Wesley L. Harris’s life is a testament to the power of mentorship and determination. Harris, born in 1941 in Richmond, Virginia, grew up during the tumultuous years of the Civil Rights Movement and faced an environment fraught with challenges. His parents, both of whom only had a third-grade education, walked to Richmond from rural Virginia counties when the Great Depression left the region’s farming communities destitute. They found work as laborers in the city’s tobacco factories but pushed their son to pursue higher education so he could live a better life.

Today, Harris is a professor of aeronautics and astronautics at MIT and heads the school’s Hypersonic Research Laboratory. More importantly, he is committed to fostering the next generation of engineers, particularly students of color.

“I’ve been keeping my head down, working with students of color—especially at the Ph.D. level—to produce more scholars,” Harris says. “I do feel good about that.”

From physics to aerospace engineering

Harris’s journey into the world of science began under the guidance of his physics teacher at the all-Black Armstrong High School, in Richmond. The instructor taught Harris how to build a cloud chamber to investigate the collision of alpha particles with water droplets. The chamber made it possible to visualize the passage of ionizing radiation emitted by radium 226, which Harris sourced from a wristwatch that used the substance to make the watch hands glow in the dark.

The project won first prize at Virginia’s statewide Black high school science fair, and he took the bold step of signing up for a separate science fair held for the state’s White students. Harris’s project received the third-place prize in physics at that event.

Those awards and his teacher’s unwavering belief in Harris’s potential pushed him to aim higher. He says that he wanted nothing more than to become a physicist like her. Ironically, it was also her influence that led him to shift his career path from physics to aeronautical engineering.

When discussing which college he should attend, she spoke to him as though he were a soldier getting his marching orders. “Wesley, you will go to the University of Virginia [in Charlottesville],” she proclaimed.

Harris applied, knowing full well that the school did not allow Black students in the 1960s to pursue degrees in mathematics, physics, chemistry, English, economics, or political science.

The only available point of entry for him was the university’s School of Engineering. He chose aerospace as his focus—the only engineering discipline that interested him. Harris became one of only seven Black students on a campus with 4,000 undergrads and the first Black student to join the prestigious Jefferson Society literary and debate club. He graduated in 1964 with a bachelor’s degree in aerospace engineering. He went on to earn his master’s and doctoral degrees in aerospace engineering from Princeton in 1966 and 1968, respectively.

Harris’s Ph.D. thesis advisor at Princeton reinforced the values of mentorship and leadership instilled by his high school teacher, urging Harris to focus not only on his research but on how he could uplift others.

Harris began his teaching career by breaking down barriers at the University of Virginia in 1968. He was the first Black person in the school’s history to be offered a tenured faculty position. He was also the university’s first Black engineering professor. In 1972, he joined MIT as a professor of aeronautics and astronautics.

Harris’s dedication to supporting underrepresented minority groups at MIT began early in his tenure. In 1975, he founded the Office of Minority Education, where he pioneered innovative teaching methods such as videotaping and replaying lectures, which helped countless students succeed. “Some of those old videotapes may still be around,” he says, laughing.

“I’ve been keeping my head down, working with students of color—especially at the Ph.D. level—to produce more scholars. I do feel good about that.”

Over the years, he has periodically stepped away from MIT to take on other roles, including Program Manager in the Fluid and Thermal Physics Office and as manager of Computational Methods at NASA’s headquarters in Washington, D.C., from 1979 to 1980. He returned to NASA in 1993 and served as Associate Administrator for Aeronautics, overseeing personnel, programs, and facilities until 1995.

He also served as Chief Administrative Officer and Vice President at the University of Tennessee Space Institute in Knoxville from 1990 to 1993 and as Dean of Engineering at the University of Connecticut, in Storrs, from 1985 to 1990.

He was selected for membership in an oversight group convened by the U.S. House of Representatives Science Subcommittee on Research and Technology to monitor the funding activities of the National Science Foundation. He has also been a member and chair of the U.S. Army Science Board.

Solving problems with aircraft

Harris is a respected aeronautical innovator. Near the end of the Vietnam War, the U.S. Army approached MIT to help it solve a problem. Helicopters were being shot down by the enemy, who had learned to distinguish attack helicopters from those used for performing reconnaissance or transporting personnel and cargo by the noise they made. The Army needed a solution that would reduce the helicopters’ acoustic signatures without compromising performance. Harris and his aeronautics team at MIT delivered that technology. In January 1978, they presented a lab report detailing their findings to the U.S. Department of Defense. “Experimental and Theoretical Studies on Model Helicopter Rotor Noise” was subsequently published in The Journal of Sound and Vibration. A year later, Harris and his colleagues at the Fluid Dynamic Research Laboratory wrote another lab report on the topic, “Parametric Studies of Model Helicopter Blade Slap and Rotational Noise.”

Harris has also heightened scientists’ understanding of the climate-altering effects of shock waves propagating upward from aircraft flying at supersonic speeds. He discovered that these high-speed airflows trigger chemical reactions among the carbon, oxides, nitrides, and sulfides in the atmosphere.

For these and other contributions to aerospace engineering, Harris, a member of the American Institute of Aeronautics and Astronautics, was elected in 1995 to the National Academy of Engineering. In 2022, he was named the academy’s vice president.

A model of educational leadership

Despite his technical achievements, Harris says his greatest fulfillment comes from mentoring students. He takes immense pride in the four students who recently earned doctorates in hypersonics under his guidance, especially a Black woman who graduated this year.

Harris’s commitment to nurturing young talent extends beyond his graduate students. For more than two decades, he has served as a housemaster at MIT’s New House residence hall, where he helps first-year undergraduate students successfully transition to campus life.

“You must provide an environment that fosters the total development of the student, not just mastery of physics, chemistry, math, and economics,” Harris says.

He takes great satisfaction in watching his students grow and succeed, knowing that he helped prepare them to make a positive impact on the world.

Reflecting on his career, Harris acknowledges the profound impact of the mentors who guided him. Their lessons continue to influence his work and his unwavering commitment to mentoring the next generation.

“I’ve always wanted to be like my high school teacher—a physicist who not only had deep knowledge of the scientific fundamentals but also compassion and love for Black folks,” he says.

Through his work, Harris has not only advanced the field of aerospace engineering but has also paved the way for future generations to soar.

Over the past 25 years, the longest driving range of an electric vehicle on a single charge has gone from about 260 kilometers to slightly over 800 km. Increasingly, these advanced battery packs have also begun storing energy from the grid or renewable sources to power homes or businesses. No wonder, then, that the global automotive battery market has surpassed US $50 billion a year, and there is increasing pressure to produce greater numbers of even better batteries.

Now, several companies are applying a well-established chemical technique called atomic layer deposition (ALD) to coat battery electrodes with metal oxides or nitrides, which they claim improves both the energy capacity and the life-span of lithium-ion batteries. The companies include Thornton, Colo.–based Forge Nano, Picosun (a wholly owned subsidiary of Santa Clara, Calif.–based Applied Materials), and Beneq, in Espoo, Finland. The companies are leveraging the technique, which was originally developed in the 1960s. After years of refining their respective processes, these companies now hope to gain a toehold in markets for EV and smartphone batteries dominated by such giants as CATL, Panasonic, and Samsung.

Of the three, Forge Nano appears to have the most-developed technology. The company recently announced that its subsidiary, Forge Battery, has begun sending samples of a prototype battery cell made with ALD-coated materials to customers for testing. Forge Nano says its proprietary ALD formulation, which it calls Atomic Armor, makes batteries’ electrodes better at storing energy and helps them last longer.

What Goes Into a Lithium-Ion Battery?

The batteries found in today’s electric vehicles and smartphones consist of three main components. The anode, or negative electrode, usually made of graphite, is where lithium ions are stored during the charging process. The cathode (positive electrode) is made of a lithium-metal oxide such as lithium cobalt oxide or lithium-iron phosphate. Then there’s the electrolyte, which is a lithium salt dissolved in an organic solvent that allows lithium ions to move between the anode and cathode. Also important is the separator, a semiporous material that allows the movement of ions between the cathode and anode during charging and discharging but blocks the flow of electrons directly between the two, which would quickly short out the battery.

A cathode coating is deposited for R&D battery cells by Forge Nano.Forge Nano

Coating the materials that make up the anode, cathode, and separator at the molecular level, these companies say, boosts batteries’ performance and durability without an appreciable increase in their weight or volume.

The films are formed by a chemical reaction between two gaseous precursor substances, which are introduced to the substrate by turns. The first one reacts with the substrate surface at active sites, the points on the precursor molecules and on the surface of the substrate where the two materials chemically bond. Then, after all the nonreacted precursor gas is pumped away, the next precursor is introduced and bonds with the first precursor at their respective active sites. ALD technology is self-terminating, meaning that when all active sites are filled, the reaction stops. The film forms one atomic layer at a time, so its thickness can be set with precision as fine as a few tenths of a nanometer simply by cutting off exposure of the substrate to the precursors once the desired coating thickness is reached.

In a conventional lithium-ion battery, with a graphite anode, silicon (and sometimes other materials) is added to the graphite to improve the anode’s ability to store ions. The practice boosts energy density, but silicon is much more prone to side reactions with the electrolyte and to expansion and contraction during charging and discharging, which weakens the electrode. Eventually, the mechanical degradation diminishes the battery’s storage capacity. ALD technology, by coating anode molecules with a protective layer, enables a higher proportion of silicon in the anode while also inhibiting the expansion-contraction cycles and thereby slowing the mechanical degradation. The result is a lighter, more energy-dense battery that is more durable than conventional lithium-ion batteries.

Picosun says its ALD technology has been used to create coated nickel oxide anodes with more than twice the energy storage capacity and three times the energy density of those relying on traditional graphite.

How big is the benefit? Forge Nano says that although the third-party testing and validation are underway, it’s too soon to make definitive statements about the coating-enhanced batteries’ life-spans. But a company spokesperson told IEEE Spectrum the data it has received thus far indicates that specific energy is improved by 15 percent compared with that of comparable batteries currently on the market.

The company has made a big bet that the players all along the battery-production chain—from fabricators of anodes and cathodes to Tier 1 battery suppliers, and even electric-vehicle manufacturers—will view its take on ALD as a must-have step in battery manufacturing. Forge Battery is building a 25,700-square-meter gigafactory in North Carolina that it says will turn out 1 gigawatt-hour of its Atomic Armor–enhanced lithium-ion cells and finished batteries when it becomes operational in 2026.

NASCAR, the stock car racing sanctioning body known for its high-octane events across the United States, is taking a significant step toward a greener future. In July, during the Chicago Street Race event, NASCAR unveiled a prototype battery-powered race car that marks the beginning of its push to decarbonize motorsports. This move is part of NASCAR’s broader strategy to achieve net-zero emissions by 2035.

The electric prototype represents a collaborative effort between NASCAR and its traditional Original Equipment Manufacturer (OEM) partners—Chevrolet, Ford, and Toyota—along with ABB, a global technology leader. Built by NASCAR engineers, the car features three 6-Phase motors from Stohl Advanced Research and Development, an Austrian specialist in electric vehicle powertrains. These motors together produce 1,000 kilowatts at peak power, equivalent to approximately 1,300 horsepower. The energy is supplied by a 78-kilowatt-hour liquid-cooled lithium-ion battery, operating at 756 volts, though the specific battery chemistry remains a closely guarded secret.

C.J. Tobin, Senior Engineer of Vehicle Systems at NASCAR and the lead engineer on the EV prototype project, explained the motivation behind the development. He told IEEE Spectrum that “The push for electric vehicles is continuing to grow, and when we started this project one and a half years ago, that growth was rapid. We wanted to showcase our ability to put an electric stock car on the track in collaboration with our OEM partners. Our racing series have always been a platform for OEMs to showcase their stock cars, and this is just another tool for them to demonstrate what they can offer to the public.”

Eleftheria Kontou, a professor of civil and environmental engineering at the University of Illinois Urbana-Champaign whose primary research focus is transportation engineering, said in an interview that “It was an excellent introduction of the new technology to NASCAR fans, and I hope that the fans will be open to seeing more innovations in that space.”

John Probst, NASCAR’s SVP of Innovation and Racing Development speaks during the unveiling of the new EV prototype. Jared C. Tilton/Getty Images

The electric race car is not just about speed; it’s also about sustainability. The car’s body panels are made from ampliTex, a sustainable flax-based composite supplied by Bcomp, a Swiss manufacturer specializing in composites made from natural fibers. AmpliTex is lighter, more moldable, and more durable than traditional materials like steel or aluminum, making the car more efficient and aerodynamic.

Regenerative braking is another key feature of the electric race car. As it slows down, the car can convert some of its kinetic energy into electric charge that feeds back into the battery. This feature most advantageous on road courses like the one in Chicago and on short oval tracks like Martinsville Speedway in Virginia.

“The Chicago Street Race was a great introduction for the EV prototype because it happens in a real-world setup where electric vehicles tend to thrive,” says Kontou, who also serves on the Steering Committee of the Illinois Alliance for Clean Transportation. “[It was a good venue for the car’s unveiling] because navigating the course requires more braking than is typical at many speedway tracks.”
Though the electric prototype is part of a larger NASCAR sustainability initiative, “There are no plans to use the electric vehicle in competition at this time,” a spokesman said. “The internal combustion engine plays an important role in NASCAR and there are no plans to move away from that.” So, die-hard stock-car racing fans can still anticipate the sounds and smells of V-8 engines burning gasoline as they hurtle around tracks and through street courses.

“The Chicago Street Race was a great introduction for the EV prototype because it happens in a real-world setup where electric vehicles tend to thrive.” —Eleftheria Kontou, University of Illinois

In its sustainability efforts, NASCAR lags well behind Formula One, its largest rival atop the world’s motorsports hierarchy. Since 2014, Formula One’s parent organization, the Fédération Internationale de l’Automobile (FIA), has had an all-electric racing spinoff, called Formula E. For the current season, which began in July, the ABB FIA Formula E World Championship series boasts 11 teams competing in 17 races. This year’s races feature the league’s third generation of electric race cars, and a fourth generation is planned for introduction in 2026.

Asked how NASCAR plans to follow through on its pledge to make its core operations net-zero emissions by its self-imposed target date, the spokesman pointed to changes that would counterbalance the output of traditional stock cars, which are notorious for their poor fuel efficiency and high carbon emissions. Those include 100 percent renewable electricity at NASCAR-owned racetracks and facilities, and tradeoffs such as recycling and on-site charging stations for use by fans with EVs.

The spokesman also noted that NASCAR and its OEM partners are developing racing fuel that’s more sustainable in light of the fact that stock cars consume, on average, about 47 liters for every 100 km they drive (5 miles per gallon). For comparison, U.S. federal regulators announced in June that they would begin enforcing an industry-wide fleet average of approximately 5.6 liters per 100 kilometers (50.4 miles per gallon) for model year 2031 and beyond. Fortunately for NASCAR, race cars are exempt from fuel-efficiency and tailpipe-emissions rules.

While some may be tempted to compare NASCAR’s prototype racer with the cars featured in the ABB FIA Formula E World Championship, Tobin emphasized that NASCAR’s approach in designing the prototype was distinct. “Outside of us seeing that there was a series out there racing electric vehicles and seeing how things were run with Formula E, we leaned heavily on our OEMs and went with what they wanted to see at that time,” he said.

The apparently slow transition to electric vehicles in NASCAR is seen by some in the organization as both a response to environmental concerns and a proactive move to stay ahead of potential legislation that could threaten the future of motorsports. “NASCAR and our OEM partners want to be in the driver’s seat, no matter where we’re going,” says Tobin. “With the development of [the NextGen EV prototype], we wanted to showcase the modularity of the chassis and what powertrains we can build upon it—whether that be alternative fuels, battery electric power, or something unforeseen in the future…We want to continue to push the envelope.”

According to the International Maritime Organization, shipping was responsible for over 1 billion tonnes of carbon dioxide emissions in 2018. A significant share of those emissions came from seaport activities, including ship berthing, cargo handling, and transportation within port areas. In response, governments, NGOs, and environmental watchdog groups are sounding alarms and advocating for urgent measures to mitigate pollution at the world’s ports.

One of the most promising solutions for the decarbonization of port operations involves electrifying these facilities. This plan envisions ships plugging into dockside electric power rather than running their diesel-powered auxiliary generators for lighting, cargo handling, heating and cooling, accommodation, and onboard electronics. It would also call for replacing diesel-powered cranes, forklifts, and trucks that move massive shipping containers from ship to shore with battery-powered alternatives.

To delve deeper into this transformative approach, IEEE Spectrum recently spoke with John Prousalidis, a leading advocate for seaport electrification. Prousalidis, a professor of marine electrical engineering at the National Technical University of Athens, has played a pivotal role in developing standards for seaport electrification through his involvement with the IEEE, the International Electrical Commission (IEC), and the International Organization for Standardization (ISO). As vice-chair of the IEEE Marine Power Systems Coordinating Committee, he has been instrumental in advancing these ideas. Last year, Prousalidis co-authored a key paper titled “Holistic Energy Transformation of Ports: The Proteus Plan” in IEEE Electrification Magazine. In the paper, Prousalidis and his co-authors outlined their comprehensive vision for the future of port operations. The main points of the Proteus plan have been integrated in the policy document on Smart and Sustainable Ports coordinated by Prousalidis within the European Public Policy Committee Working Group on Energy; the policy document was approved in July 2024 by the IEEE Global Policy Committee.

Professor John ProusalidisJohn Prousalidis

What exactly is “cold ironing?”

John Prousalidis: Cold ironing involves shutting down a ship’s propulsion and auxiliary engines while at port, and instead, using electricity from shore to power onboard systems like air conditioning, cargo handling equipment, kitchens, and lighting. This reduces emissions because electricity from the grid, especially from renewable sources, is more environmentally friendly than burning diesel fuel on site. The technical challenges include matching the ship’s voltage and frequency with that of the local grid, which, in general, varies globally, while tackling grounding issues to protect against short circuits.

IEEE, along with IEC and ISO, have developed a joint standard, 80005, which is a series of three different standards for high-voltage and low-voltage connection. It is perhaps (along with Wi-Fi, the standard for wireless communication) the “hottest” standard because all governmental bodies tend to make laws stipulating that this is the standard that all ports need to follow to supply power to ships.

How broad has adoption of this standard been?

Prousalidis: The European Union has mandated full compliance by January 1, 2030. In the United States, California led the way with similar measures in 2010. This aggressive remediation via electrification is now being adopted globally, with support from the International Maritime Organization.

Let’s talk about another interesting idea that’s part of the plan: regenerative braking on cranes. How does that work?

Prousalidis: When lowering shipping containers, cranes in regenerative braking mode convert the kinetic energy into electric charge instead of wasting it as heat. Just like when an electric vehicle is coming to a stop, the energy can be fed back into the crane’s battery, potentially saving up to 50 percent in energy costs—though a conservative estimate would be around 20 percent.

What are the estimated upfront costs for implementing cold ironing at, say, the Port of Los Angeles, which is the largest port in the United States?

Prousalidis: The cost for a turnkey solution is approximately US $1.7 million per megawatt, covering grid upgrades, infrastructure, and equipment. A rough estimate using some established rules of thumb would be about $300 million. The electrification process at that port has already begun. There are, as far as I know, about 60 or more electrical connection points for ships at berths there.

How significant would the carbon reduction from present levels be if there were complete electrification with renewable energy at the world’s 10 biggest and busiest ports?

Prousalidis: If ports fully electrify using renewable energy, the European Union’s policy could achieve a 100-percent reduction in ship emissions in the port areas. According to the IMO’s approach, which considers the energy mix of each country, it could lead to a 60-percent reduction. This significant emission reduction means lower emissions of CO₂, nitrogen oxides, sulfur oxides, and particulate matter, thus reducing shipping’s contribution to global warming and lowering health risks in nearby population centers.

If all goes according to plan, and every country with port operations goes full bore toward electrification, how long do you think it will realistically take to completely decarbonize that aspect of shipping?

Prousalidis: As I said, the European Union is targeting full port electrification by 1 January 2030. However, with around 600 to 700 ports in Europe alone, and the need for grid upgrades, delays are possible. Despite this, we should focus on meeting the 2030 deadline rather than anticipating extensions. This recalls the words of Gemini and Apollo pioneer astronaut, Alan Shepard, when he explained the difference between a test pilot and a normal professional pilot: “Suppose each of them had 10 seconds before crashing. The conventional pilot would think, In 10 seconds I’m going to die. The test pilot would say to himself, I’ve got 10 seconds to save myself and save the craft.” The point is that, in a critical situation like the fight against global warming, we should focus on the time we have to solve the problem, not on what happens after time runs out. But humanity doesn’t have an eject button to press if we don’t make every effort to avoid the detrimental consequences that will come with failure of the “save the planet” projects.

There were early signs that Muhammad Hamza Ihtisham was born to excel in engineering or computer science, but family tradition initially steered him toward a career in medicine. Ihtisham’s mother and other family members were medical professionals. His father is a businessman.

Even though his father had dreamed of having a son in the engineering field, it was assumed that Ihtisham would become a doctor. And he almost did. But when he didn’t pass the medical qualifying exams in high school, he saw it as a sign to switch professions.

Muhammad Hamza Ihtisham

Employer:

Jazz in Lahore, Pakistan

Title:

Network experience specialist in radio

Member grade:

IEEE member

Alma mater:

University of the Punjab

“I asked my parents and my principal for permission to switch my focus from medicine to computer science,” he says. Although the change took effect only three months before he had to take exams, he scored high enough to place third among the computer science students at his school. He has never looked back.

Ihtisham is now a network experience specialist in radio at the largest telecommunications provider in Pakistan: Lahore-based Jazz. Ihtisham monitors, supervises, and troubleshoots nationwide wireless networks and is a team player who implements smart systems and AI-based solutions to optimize network performance.

“We are working with 2G, 3G, and 4G network supervision,” he says, “and we’re also evolving for 5G and optical fiber networks.”

Muhammad Hamza Ihtisham chats with 2018 IEEE President Jim Jefferies.Muhammad Hamza Ihtisham

Early evidence of STEM affinity

Ihtisham didn’t need much encouragement to become an engineer, he says, adding that he always has wanted to work with technology.

When he was young, his father bought him a computer with a Pentium II CPU “at a time when there were very few computers in my town,” he says.

Ihtisham’s curiosity led him to dismantle and explore its components, fostering a deeper interest in technology.

“I destroyed many motherboards and processors when I pulled them out of the computer to see how they worked,” he says. It was part of his innate tendency to get to the bottom of how things worked. “I still have that spark in me, that inner child who wants to open things up and investigate how they work.”

He earned a bachelor’s degree in electrical engineering with a specialization in telecommunications from the University of the Punjab in 2018. He returned to pursue a master’s degree in industrial engineering and management—which he received in 2022.

Thanks to his IEEE connections, Ihtisham secured his position at Jazz even before getting his bachelor’s degree. As the university’s IEEE student branch chair, Ihtisham invited an engineer from Jazz to speak to students on campus. When Ihtisham later showed up at the company for a job interview, that same engineer was the department head and immediately recognized him.

Since his college days, Ihtisham has poured time and energy into giving back to the profession through participation in IEEE. He founded his school’s student chapter and today serves as chair of the IEEE Lahore Section’s Young Professionals group. He is also the deputy lead of the global technical and operation committee of the IEEE Young Professionals mentoring program, which connects experts with mentees to help them learn and further their career.

Active IEEE student leader

Ihtisham entered college thinking he would become a computer scientist, but before long he became convinced that his true passion lay in engineering. Noticing a gap in student activities within the school’s EE department, he joined IEEE in his third semester.

Although the university was more than 150 years old, electrical engineering was a relatively new course of study there.

“My graduating class had only the 10th cohort of graduates to earn that degree from the university,” he says.

As founder of the school’s IEEE student branch, Ihtisham set about adding activities and opportunities for would-be engineers that he felt were missing. He was the branch’s first chair, organizing activities, boosting membership, and overseeing initiatives that impacted his university and the wider IEEE Lahore Section. He was then appointed a student representative for the section.

“That was a turning point for me,” he says.

He originally started volunteering with IEEE for a pragmatic purpose that served the entire engineering student body, he says, but as he settled into his new leadership roles, volunteering became a source of personal fulfillment and development.

“When I started my IEEE journey, I was not prepared. But I worked on my leadership, my behavior, and improving my soft skills. So, you could say my involvement with IEEE has transformed my personality and served as leadership training.”

For his efforts, he has been recognized with several awards including the IEEE Lahore Section’s 2018 Outstanding Volunteer for organizing student activities and conferences.

“When I started my IEEE journey, I was not well groomed,” Ihistham says. “But I worked on my leadership, my behavior, and improving my soft skills. So, you could say my involvement with IEEE has transformed my personality and served as leadership training.”

The communications and negotiating skills he picked up by networking with IEEE members across the globe have benefited him at Jazz, he says.

His dedication to IEEE didn’t end with his student years. Today his roles involve mentoring, networking, and leading initiatives to foster growth and collaboration in the engineering community.

Now his leadership skills help him manage and motivate other volunteers and mentor engineering students. He received the 2021 IEEE MGA Young Professionals Achievement Award for organizing YP activities and the 2021 IEEE IAS Young Member Service Award for virtually engaging IEEE Industry Applications Society members during the COVID-19 pandemic.

Advice for aspiring engineers

To students considering a career in electrical engineering, Ihtisham emphasizes the importance of finding the right mentors and embracing open-source collaboration. He advises discussing ideas with experts to gain valuable insights and foster innovative thinking.

His success story underscores the value of mentorship, continuous learning, and community engagement. While he was in graduate school working toward his master’s degree, he began doing research to develop an effective and reliable brain-computer interface. He talked with the medical professionals in his family for information about how the brain works but then found himself at an impasse because there were not enough datasets in Pakistan for training his machine-learning software.

He reached out to the IEEE community and found a mentor for the project at the University of New South Wales in Sydney. Their collaboration was fruitful enough that Ihtisham was invited to present a TEDx talk on what he had learned about addiction and neurofeedback.

Based on that project, he took home third prize in the IEEE IAS Chapters and Membership Department Zucker Undergraduate Student Design Contest in 2019.

Ihtisham’s journey with IEEE exemplifies the impact of dedication, mentorship, and continued learning on building an interesting and successful engineering career.

“My success is having an impact on my younger cousins,” he says. “If they want to pursue a career in engineering or another STEM field, they have someone in the family who can guide them.”

Stop for a second and think about the Internet without digital images or video. There would be no faces on Facebook. Instagram and TikTok probably wouldn’t exist. Those Zoom meetings that took the place of in-person gatherings for school or work during the height of the COVID-19 pandemic? Not an option.

Digital audio’s place in our Internet-connected world is just as important as still images and video. It has changed the music business—from production to distribution to the way fans buy, collect, and store their favorite songs.

What do those millions of profiles on LinkedIn, dating apps, and social media platforms (and the inexhaustible selection of music available for download online) have in common? They rely on a compression algorithm called the discrete cosine transform, or DCT, which played a major role in allowing digital files to be transmitted across computer networks.

“DCT has been one of the key components of many past image- and video-coding algorithms for more than three decades,” says Touradj Ebrahimi, a professor at Ecole Polytechnique Fédérale de Lausanne, in Switzerland, who currently serves as chairman of the JPEG standardization committee. “Only a few image-compression standards not using DCT exist today,” he adds.

The Internet applications people use every day but largely take for granted were made possible by scientists and engineers who, for the most part, toiled in anonymity. One such “hidden figure” is Nasir Ahmed, the Indian-American engineer who figured out an elegant way to cut down the size of digital image files without sacrificing their most critical visual details.

Ahmed published his seminal paper about the discrete cosine transform compression algorithm he invented in 1974, a time when the fledgling Internet was exclusively dial-up and text-based. There were no pictures accompanying the words, nor could there have been, because Internet data was transmitted over standard copper telephone landlines, which was a major limitation on speed and bandwidth.

“Only a few image-compression standards not using DCT exist today.” –Touradj Ebrahimi, EPFL

These days, with the benefit of superfast chips and optical-fiber networks, data download speeds for a laptop with a fiber connection reach 1 gigabit per second. So, a music lover can download a 4-minute song to their laptop (or more likely a smartphone) in a second or two. In the dial-up era, when Internet users’ download speeds topped out at 56 kilobits per second (and were usually only half that fast), pulling down the same song from a server would have taken nearly all day. Getting a picture to appear on a computer’s screen was a process akin to watching grass grow.

Ahmed was convinced there had to be a way to cut down the size of digital files and speed up the process. He set off on a quest to represent with ones and zeros what is critical to an image being legible, while tossing aside the bits that are less important. The answer, which built on the earlier work of mathematician and information-theory pioneer Claude Shannon, took a while to come into focus. But because of Ahmed’s determination and unwavering belief in the value of what he was doing, he persevered even after others told him that it was not worth the effort.

Raised to Love Technology

It seemed almost preordained that Ahmed would have a career in one of the STEM fields. Nasir, who was born in Bengaluru, India, in 1940, was raised by his maternal grandparents. Ahmed’s grandfather was an electrical engineer who told him that he had been sent to the United States in 1919 to work at General Electric‘s location in Schenectady, N.Y. He shared tales of his time in the United States with his grandson and encouraged young Nasir to emigrate there. In 1961, after earning a bachelor’s degree in electrical engineering at the University of Visvesvaraya College of Engineering, in Bengaluru, Ahmed did just that, leaving India that fall for graduate school at the University of New Mexico, in Albuquerque. Ahmed earned a master’s degree and a Ph.D. in electrical engineering in 1963 and 1966, respectively.

During his first year in Albuquerque, he met Esther Parente, a graduate student from Argentina. They soon became inseparable and were married while he was working toward his doctorate. Sixty years later, they are still together.

The Seed of an Idea

In 1966, Ahmed, fresh out of grad school with his Ph.D., was hired as a principal research engineer at Honeywell’s newly created computer division. While there, Ahmed was first exposed to Walsh functions, a technique for analyzing digital representations of analog signals. The fast algorithms that could be created based on Walsh functions had many potential applications. Ahmed focused on using these signal-processing and analysis techniques to reduce the file size of a digital image without losing too much of the visual detail in the uncompressed version.

That research focus remained his primary interest when he returned to academia, taking a job as a professor in the electrical and computer engineering department at Kansas State University, in 1968.

Ahmed, like dozens of other researchers around the globe, was obsessed with finding the answer to a single question: How do you create a mathematical formula for deciphering which of the ones and zeros that represent a digital image need to be kept and which can be thrown away? The things he’d learned at Honeywell gave him a framework for understanding the elements of the problem and how to attack it. But the majority of the credit for the eventual breakthrough has to go to Ahmed’s steely determination and willingness to take a gamble on himself.

In 1972, he sought grant funding that would let him afford to spend the months between Kansas State’s spring and fall semesters furthering his ideas. He applied for a U.S. National Science Foundation grant, but was denied. Ahmed recalls the moment: “I had a strong intuition that I could find an efficient way to compress digital signal data. But to my surprise, the reviewers said the idea was too simple, so they rejected the proposal.”

Undaunted, Ahmed and his wife worked to make the salary he earned during the nine-month school year last through the summer so he could focus on his research. Money was tight, the couple recalls, but that moment of financial belt-tightening only seemed to heighten Ahmed’s industriousness. They persevered, and Ahmed’s long days and late nights in the lab eventually yielded the desired result.

DCT Compression Comes Together

Ahmed took a technique for turning the array of image-processing data representing an image’s pixels into a waveform, effectively rendering it as a series of waves with oscillating frequencies, and combined it with cosine functions that were already being used to model phenomena such as light waves, sound waves, and electric current. The result was a long string of numbers with values bounded by 1 and –1. Ahmed realized that by quantizing this string of values and performing a Fourier transformation to break the function into its constituent frequencies, each pixel’s data could be represented in a way that was helpful for deciding what data points must be kept and what could be omitted. Ahmed observed that the lower-frequency waves corresponded to the necessary or “high information” regions of the image, while the higher-frequency waves represented the bits that were less important and could therefore be approximated. The compressed-image files he and his team produced were one-tenth the size of the originals. What’s more, the process could be reversed, and a shrunken data file would yield an image that was sufficiently similar to the original.

After another two years of laborious testing, with he and his two collaborators running computer programs written on decks of data punch cards, the trio published a paper in IEEE Transactions On Computers titled “Discrete Cosine Transform” in January 1974. Though the paper’s publication did not make it immediately clear, the worldwide search for a reliable method of doing the lossy compression that Claude Shannon had postulated in the 1940s was over.

JPEGs, MPEGs, and More

It wasn’t until 1983 that the International Organization for Standardization (ISO) began working on the technology that would allow photo-quality images to accompany text on the screens of computer terminals. To that end, ISO established the Joint Photographic Experts Group, better known by the ubiquitous acronym JPEG. By the time the first JPEG standard was published in 1992, DCT and advances made by a cadre of other researchers had come to be recognized by the group as basic elements of their method for the digital compression and coding of still images. “This is the beauty of standardization, where several dozen bright minds are behind the success of advances such as JPEG,” says Ebrahimi.

And because video can be described as a succession of still images, Ahmed’s technique was also well suited to making video files smaller. DCT was the compression technique of choice when ISO and the international Electrotechnical Commission (IEC) established the Moving Picture Experts Group, or MPEG, for the compression and coding of audio, video, graphics, and genomic data in 1988. When the first MPEG standard was published in 1993, the World Wide Web that now includes Google Maps, dating apps, and e-commerce businesses was just four years old.

The ramping up of computer speeds and network bandwidth during that decade—along with the ability to transmit pictures and video via much smaller files—quickly transformed the Internet before anyone knew that Amazon would eventually let readers judge millions of books by their covers.

Having solved the problem that had monopolized his time and attention for several years, Ahmed resumed his career in academia. In 1993, the year the first MPEG standard went on the books, Ahmed left Kansas State and returned to the University of New Mexico. There he was a presidential professor of electrical and computer engineering until 1989, when he was promoted to chair of the ECE department. Five years after that, he became dean of UNM’s school of engineering­. Ahmed held that post for two years until he was named associate provost for research and dean of graduate studies. He stayed in that job until he retired from the university in 2001 and was named professor emeritus.

In July, two companies announced a collaboration aimed at helping to decarbonize maritime fuel technology. The companies, Brooklyn-based Amogy and Osaka-based Yanmar, say they plan to combine their respective areas of expertise to develop power plants for ships that use Amogy’s advanced technology for cracking ammonia to produce hydrogen fuel for Yanmar’s hydrogen internal combustion engines.

This partnership responds directly to the maritime industry’s ambitious goals to significantly reduce greenhouse gas emissions. The International Maritime Organization (IMO) has set stringent targets. It is calling for a 40 percent reduction in shipping’s carbon emissions from 2008 levels by 2030. But will the companies have a commercially available reformer-engine unit available in time for shipping fleet owners to launch vessels featuring this technology by the IMO’s deadline? The urgency is there, but so are the technical hurdles that come with new technologies.

Shipping accounts for less than 3 percent of global human-caused CO₂ emissions, but decarbonizing the industry would still have a profound impact on global efforts to combat climate change. According to the IMO’s 2020 Fourth Greenhouse Gas Study, shipping produced 1,056 million tonnes of carbon dioxide in 2018.

Amogy and Yanmar did not respond to IEEE Spectrum‘s requests for comment about the specifics of how they plan to synergize their areas of focus. But John Prousalidis, a professor at the National Technical University of Athens’s School of Naval Architecture and Marine Engineering, spoke with Spectrum to help put the announcement in context.

“We have a long way to go. I don’t mean to sound like a pessimist, but we have to be very cautious.” —John Prousalidis, National Technical University of Athens

Prousalidis is among a group of researchers pushing for electrification of seaport activities as a means of cutting greenhouse gas emissions and reducing the amount of pollutants such as nitrogen oxides and sulfur oxides being spewed into the air by ships at berth and by the cranes, forklifts, and trucks that handle shipping containers in ports. He acknowledged that he hasn’t seen any information specific to Amogy and Yanmar’s technical ideas for using ammonia as ships’ primary fuel source for propulsion, but he has studied maritime sector trends long enough—and helped create standards for the IEEE, the International Electrotechnical Commission (IEC), and the International Organization for Standardization (ISO)—in order to have a strong sense of how things will likely play out.

“We have a long way to go,” Prousalidis says. “I don’t mean to sound like a pessimist, but we have to be very cautious.” He points to NASA’s Artemis project, which is using hydrogen as its primary fuel for its rockets.

“The planned missile launch for a flight to the moon was repeatedly postponed because of a hydrogen leak that could not be well traced,” Prousalidis says. “If such a problem took place with one spaceship that is the singular focus of dozens of people who are paying attention to the most minor detail, imagine what could happen on any of the 100,000 ships sailing across the world?”

What’s more, he says, bold but ultimately unsubstantiated announcements from companies are fairly common. Amogy and Yanmar aren’t the first companies to suggest tapping into ammonia for cargo ships—the industry is no stranger to plans to adopt the fuel to move massive ships across the world’s oceans.

“A couple of big pioneering companies have announced that they’re going to have ammonia-fueled ship propulsion pretty soon,” Prousalidis says. “Originally, they announced that it would be available at the end of 2022. Then they said the end of 2023. Now they’re saying something about 2025.”

Shipping produced 1,056 million tonnes of carbon dioxide in 2018.

Prousalidis adds, “Everybody keeps claiming that ‘in a couple of years’ we’ll have [these alternatives to diesel for marine propulsion] ready. We periodically get these announcements about engines that will be hydrogen-ready or ammonia-ready. But I’m not sure what will happen during real operation. I’m sure that they performed several running tests in their industrial units. But in most cases, according to Murphy’s Law, failures will take place at the worst moment that we can imagine.”

All that notwithstanding, Prousalidis says he believes these technical hurdles will someday be solved, and engines running on alternative fuels will replace their diesel-fueled counterparts eventually. But he says he sees the rollout likely mirroring the introduction of natural gas. At the point when a few machines capable of running on that type of fuel were ready, the rest of the logistics chain was not. “We need to have all these brand-new pieces of equipment, including piping, that must be able to withstand the toxicity and combustibility of these new fuels. This is a big challenge, but it means that all engineers have work to do.”

Spectrum also reached out to researchers at the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy with several questions about what Amogy and Yanmar say they are looking to pull off. The DOE’s e-mail response: “Theoretically possible, but we don’t have enough technical details (temperature of coupling engine to cracker, difficulty of manifolding, startup dynamics, controls, etc.) to say for certain and if it is a good idea or not.”

This article was updated on 5 August 2024 to correct global shipping emission data.

Schoolchildren around the world are told that they have the potential to be great, often with the cheery phrase: “The sky’s the limit!”

Gladys West took those words literally.

While working for four decades as a mathematician and computer programmer at the U.S. Naval Proving Ground (now the Naval Surface Warfare Center) in Dahlgren, Va., she prepared the way for a satellite constellation in the sky that became an indispensable part of modern life: the Global Positioning System, or GPS.

The second Black woman to ever work at the proving ground, West led a group of analysts who used satellite sensor data to calculate the shape of the Earth and the orbital routes around it. Her meticulous calculations and programming work established the flight paths now used by GPS satellites, setting the stage for navigation and positioning systems on which the world has come to rely.

For decades, West’s contributions went unacknowledged. But she has begun receiving overdue recognition. In 2018 she was inducted into the U.S. Air Force Space and Missile Pioneers Hall of Fame. In 2021 the International Academy of Digital Arts and Sciences presented her its Webby Lifetime Achievement Award, while the U.K. Royal Academy of Engineering gave her the Prince Philip Medal, the organization’s highest individual honor.

West was presented the 2024 IEEE President’s Award for “mathematical modeling and development of satellite geodesy models that played a pivotal role in the development of the Global Positioning System.” The award is sponsored by IEEE.

How the “hidden figure” overcame barriers

West’s path to becoming a technology professional and an IEEE honoree was an unlikely one. Born in 1930 in Sutherland, Va., she grew up working on her family’s farm. To supplement the family’s income, her mother worked at a tobacco factory and her father was employed by a railroad company.

Physical toil in the hot sun from daybreak until sundown with paltry financial returns, West says, made her determined to do something other than farming.

Every day when she ventured into the fields to sow or harvest crops with her family, her thoughts were on the little red schoolhouse beyond the edge of the farm. She recalls gladly making the nearly 5-kilometer trek from her house, through the woods and over streams, to reach the one-room school.

She knew that postsecondary education was her ticket out of farm life, so throughout her school years she made sure she was a standout student and a model of focus and perseverance.

Her parents couldn’t afford to pay for her college education, but as valedictorian of her high school class, she earned a full-tuition scholarship from the state of Virginia. Money she earned as a babysitter paid for her room and board.

West decided to pursue a degree in mathematics at Virginia State College (now Virginia State University), a historically Black school in Petersburg.

At the time, the field was dominated by men. She earned a bachelor’s degree in the subject in 1952 and became a schoolteacher in Waverly, Va. After two years in the classroom, she returned to Virginia State to pursue a master’s degree in mathematics, which she earned in 1955.

Gladys West at her desk, meticulously crunching numbers manually in the era before computers took over such tasks.Gladys West

Setting the groundwork for GPS

West began her career at the Naval Proving Ground in early 1956. She was hired as a mathematician, joining a cadre of workers who used linear algebra, calculus, and other methods to manually solve complex problems such as differential equations. Their mathematical wizardry was used to handle trajectory analysis for ships and aircraft as well as other applications.

She was one of four Black employees at the facility, she says, adding that her determination to prove the capability of Black professionals drove her to excel.

As computers were introduced into the Navy’s operations in the 1960s, West became proficient in Fortran IV. The programming language enabled her to use the IBM 7030—the world’s fastest supercomputer at the time—to process data at an unprecedented rate.

Because of her expertise in mathematics and computer science, she was appointed director of projects that extracted valuable insights from satellite data gathered during NASA missions. West and her colleagues used the data to create ever more accurate models of the geoid—the shape of the Earth—factoring in gravitational fields and the planet’s rotation.

One such mission was Seasat, which lasted from June to October 1978. Seasat was launched into orbit to test oceanographic sensors and gain a better understanding of Earth’s seas using the first space-based synthetic aperture radar (SAR) system, which enabled the first remote sensing of the Earth’s oceans.

SAR can acquire high-resolution images at night and can penetrate through clouds and rain. Seasat captured many valuable 2D and 3D images before a malfunction caused the satellite to be taken down.

Enough data was collected from Seasat for West’s team to refine existing geodetic models to better account for gravity and magnetic forces. The models were important for precisely mapping the Earth’s topography, determining the orbital routes that would later be used by GPS satellites, as well as documenting the spatial relationships that now let GPS determine exactly where a receiver is.

In 1986 she published the “Data Processing System Specifications for the GEOSAT Satellite Radar Altimeter” technical report. It contained new calculations that could make her geodetic models more accurate. The calculations were made possible by data from the radio altimeter on the GEOSAT, a Navy satellite that went into orbit in March 1985.

West’s career at Dahlgren lasted 42 years. By the time she retired in 1998, all 24 satellites in the GPS constellation had been launched to help the world keep time and handle navigation. But her role was largely unknown.

A model of perseverance

Neither an early bout of imposter syndrome nor the racial tensions that were an everyday element of her work life during the height of the Civil Rights Movement were able to knock her off course, West says.

In the early 1970s, she decided that her career advancement was not proceeding as smoothly as she thought it should, so she decided to go to graduate school part time for another degree. She considered pursuing a doctorate in mathematics but realized, “I already had all the technical credentials I would ever need for my work for the Navy.” Instead, to solidify her skills as a manager, she earned a master’s degree in 1973 in public administration from the University of Oklahoma in Norman.

After retiring from the Navy, she earned a doctorate in public administration in 2000 from Virginia Tech. Although she was recovering from a stroke at the time that affected her physical abilities, she still had the same drive to pursue an education that had once kept her focused on a little red schoolhouse.

A formidable legacy

West’s contributions have had a lasting impact on the fields of mathematics, geodesy, and computer science. Her pioneering efforts in a predominantly male and racially segregated environment set a precedent for future generations of female and minority scientists.

West says her life and career are testaments to the power of perseverance, skill, and dedication—or “stick-to-it-iveness,” to use her parlance. Her story continues to inspire people who strive to push boundaries. She has shown that the sky is indeed not the limit but just the beginning.

Autonomous vehicles have been highly anticipated because of the possibility that they will greatly reduce or perhaps eliminate the collisions that cause more than a million deaths each year. But safety isn’t the only potential benefit self-driving cars can offer: Teams of researchers around the world are showing that autonomous vehicles can also drive more efficiently than humans can. A U.S. Department of Energy program called NEXTCAR (Next-Generation Energy Technologies for Connected and Automated On-Road Vehicles), for example, is betting that a mix of new smart-vehicle technologies can boost fuel efficiency by as much as 30 percent.

As part of the NEXTCAR program, San Antonio, Texas–based Southwest Research Institute (SwRI) showcased advances in autonomous vehicle technology that will improve vehicles’ fuel economy—including the fuel efficiency of nonautonomous automobiles that just so happen to be in traffic with autonomous ones. The demonstration was held at the ARPA-E Energy Inovation Summit in Dallas in late May.

Making an Efficient Autonomous Vehicle

The SwRI team retrofitted a 2021 Honda Clarity hybrid with basic autonomous features such as perception and localization. On the day of the summit, they drove the vehicle along a route encircling the parking lot of the convention center where the summit was held. SWRI’s Ranger localization system, which the researchers installed on the Honda, has a downward-facing camera that captures images of the ground. By initially mapping the driving surface, Ranger can later localize the vehicle with centimeter-level accuracy, using the ground’s unique “fingerprint” combined with GPS data. This precision ensures the vehicle drives with exceptional control.

“It’s almost like riding on rails,” says Stas Gankov, a researcher in SwRI’s power-train engineering group. For this project, his group collaborated with other divisions at the institute, such as the intelligence-systems division, which developed the autonomy software stack added to the Honda Clarity.

Just as important, however, was the addition of an ecodriving module, a key innovation by SwRI. The ecomode determines the most economical driving speed by considering various factors such as traffic lights and surrounding vehicles. This system employs predictive control algorithms to help solve a tricky optimization problem: How can cars minimize energy consumption while maintaining efficient traffic flow? SwRI’s ecomode aims to reduce unnecessary acceleration and deceleration in order to optimize energy usage without impeding other vehicles.

“Autonomous vehicles operating in ecomode influence the driving behavior of all the cars behind them.” —Stas Gankov, Southwest Research Institute

To illustrate how the technology works, the team installed a traffic signal along the demonstration pathway. Gankov says an actual traffic-light timer from a traffic-signal cabinet was connected to a TV screen, providing a visual for attendees. A dedicated short range communications (DRSC) radio was also attached, broadcasting the signal’s phase and timing information to the vehicle. This setup enabled the vehicle to anticipate the traffic light’s actions far more accurately than a human driver could.

For instance, Gankov says, if the Honda Clarity was approaching a red light that was about to turn green, it would know the light was due to change and so avoid wasting energy by braking and then accelerating again. Conversely, if the car was approaching the signal as it was about to turn from green to yellow to red, the vehicle would release the accelerator and let friction slow it to a crawl, avoiding unnecessary acceleration in an attempt to beat the light.

These autonomous driving strategies can lead to significant energy savings, benefiting not just the autonomous vehicles themselves, but also the entire traffic ecosystem.

“In a regular traffic situation, autonomous vehicles operating in ecomode influence the driving behavior of all the cars behind them,” says Gankov. “The result is that even vehicles with Level 0 autonomy use fuel more sparingly.”

The Grand Vehicle Energy Plan

SwRI has been a participant in the NEXTCAR initiative since 2017. The program’s initial phase involved 11 teams, including SwRI, Michigan Technological University, Ohio State University, and the University of California, Berkeley. SwRI, in collaboration with the University of Michigan, focused on optimizing a Toyota Prius Prime, already known for its fuel efficiency, to achieve a 20 percent improvement in energy usage through optimization algorithms and wireless communicating with its surroundings. This was accomplished without modifying the Toyota’s power train or compromising its emissions. The team utilized power split optimization, balancing the use of the gas engine and battery-propulsion system for maximum efficiency.

Building on the success of NEXTCAR’s first phase, the program entered its second phase in 2021, with just SwRI, Michigan Tech, Ohio State, and UC Berkeley remaining. The focus of NEXTCAR 2 has been determining how much automation could further enhance energy efficiency. Gankov explains that while the first phase demonstrated a 20 percent energy-efficiency improvement over a baseline 2016 or 2017 model-year vehicle with no autonomous driving capabilities, through the addition of vehicle-to-everything connectivity alone, the second phase is exploring the potential for an additional 10 percent improvement by incorporating autonomous features.

Gankov says SwRI initially intended to partner with Honda for NEXTCAR’s second phase, but when contracting issues arose, the nonprofit proceeded independently. Utilizing an autonomy platform developed by SwRI’s intelligence-systems division, the NEXTCAR team equipped the Honda Clarity with what amounted to Level 4 autonomy in a box. This autonomy system features a drive-by-wire system, allowing the vehicle to automatically adjust its speed and steering based on inputs from the autonomy software stack and the ecodriving module. This ensures the vehicle prioritizes safety while optimizing for energy efficiency.

Employing techniques like efficient highway merging were key strategies in their approach to making the most of each tank of fuel or battery charge. “For example, in heavy traffic on the highway, calculating the most optimal way to merge onto the highway without negatively affecting the energy efficiency of the vehicles already on the highway is crucial,” Gankov noted.

As NEXTCAR 2 enters its final year, the demonstration at the ARPA-E Summit served as a testament to the progress made in autonomous-vehicle technology and its potential to dramatically improve energy efficiency in transportation.

Tsunenobu Kimoto, a professor of electronic science and engineering at Kyoto University, literally wrote the book on silicon carbide technology. Fundamentals of Silicon Carbide Technology, published in 2014, covers properties of SiC materials, processing technology, theory, and analysis of practical devices.

Kimoto, whose silicon carbide research has led to better fabrication techniques, improved the quality of wafers and reduced their defects. His innovations, which made silicon carbide semiconductor devices more efficient and more reliable and thus helped make them commercially viable, have had a significant impact on modern technology.

Tsunenobu Kimoto

Employer

Kyoto University

Title

Professor of electronic science and engineering

Member grade

Fellow

Alma mater

Kyoto University

For his contributions to silicon carbide material and power devices, the IEEE Fellow was honored with this year’s IEEE Andrew S. Grove Award, sponsored by the IEEE Electron Devices Society.

Silicon carbide’s humble beginnings

Decades before a Tesla Model 3 rolled off the assembly line with an SiC inverter, a small cadre of researchers, including Kimoto, foresaw the promise of silicon carbide technology. In obscurity they studied it and refined the techniques for fabricating power transistors with characteristics superior to those of the silicon devices then in mainstream use.

Today MOSFETs and other silicon carbide transistors greatly reduce on-state loss and switching losses in power-conversion systems, such as the inverters in an electric vehicle used to convert the battery’s direct current to the alternating current that drives the motor. Lower switching losses make the vehicles more efficient, reducing the size and weight of their power electronics and improving power-train performance. Silicon carbide–based chargers, which convert alternating current to direct current, provide similar improvements in efficiency.

But those tools didn’t just appear. “We had to first develop basic techniques such as how to dope the material to make n-type and p-type semiconductor crystals,” Kimoto says. N-type crystals’ atomic structures are arranged so that electrons, with their negative charges, move freely through the material’s lattice. Conversely, the atomic arrangement of p-type crystals’ contains positively charged holes.

Kimoto’s interest in silicon carbide began when he was working on his Ph.D. at Kyoto University in 1990.

“At that time, few people were working on silicon carbide devices,” he says. “And for those who were, the main target for silicon carbide was blue LED.

“There was hardly any interest in silicon carbide power devices, like MOSFETs and Schottky barrier diodes.”

Kimoto began by studying how SiC might be used as the basis of a blue LED. But then he read B. Jayant Baliga’s 1989 paper “Power Semiconductor Device Figure of Merit for High-Frequency Applications” in IEEE Electron Device Letters, and he attended a presentation by Baliga, the 2014 IEEE Medal of Honor recipient, on the topic.

“I was convinced that silicon carbide was very promising for power devices,” Kimoto says. “The problem was that we had no wafers and no substrate material,” without which it was impossible to fabricate the devices commercially.

In order to get silicon carbide power devices, “researchers like myself had to develop basic technology such as how to dope the material to make p-type and n-type crystals,” he says. “There was also the matter of forming high-quality oxides on silicon carbide.” Silicon dioxide is used in a MOSFET to isolate the gate and prevent electrons from flowing into it.

The first challenge Kimoto tackled was producing pure silicon carbide crystals. He decided to start with carborundum, a form of silicon carbide commonly used as an abrasive. Kimoto took some factory waste materials—small crystals of silicon carbide measuring roughly 5 millimeters by 8 mm­—and polished them.

He found he had highly doped n-type crystals. But he realized having only highly doped n-type SiC would be of little use in power applications unless he also could produce lightly doped (high purity) n-type and p-type SiC.

Connecting the two material types creates a depletion region straddling the junction where the n-type and p-type sides meet. In this region, the free, mobile charges are lost because of diffusion and recombination with their opposite charges, and an electric field is established that can be exploited to control the flow of charges across the boundary.

“Silicon carbide is a family with many, many brothers.”

By using an established technique, chemical vapor deposition, Kimoto was able to grow high-purity silicon carbide. The technique grows SiC as a layer on a substrate by introducing gasses into a reaction chamber.

At the time, silicon carbide, gallium nitride, and zinc selenide were all contenders in the race to produce a practical blue LED. Silicon carbide, Kimoto says, had only one advantage: It was relatively easy to make a silicon carbide p-n junction. Creating p-n junctions was still difficult to do with the other two options.

By the early 1990s, it was starting to become clear that SiC wasn’t going to win the blue-LED sweepstakes, however. The inescapable reality of the laws of physics trumped the SiC researchers’ belief that they could somehow overcome the material’s inherent properties. SiC has what is known as an indirect band gap structure, so when charge carriers are injected, the probability of the charges recombining and emitting photons is low, leading to poor efficiency as a light source.

While the blue-LED quest was making headlines, many low-profile advances were being made using SiC for power devices. By 1993, a team led by Kimoto and Hiroyuki Matsunami demonstrated the first 1,100-volt silicon carbide Schottky diodes, which they described in a paper in IEEE Electron Device Letters. The diodes produced by the team and others yielded fast switching that was not possible with silicon diodes.

“With silicon p-n diodes,” Kimoto says, “we need about a half microsecond for switching. But with a silicon carbide, it takes only 10 nanoseconds.”

The ability to switch devices on and off rapidly makes power supplies and inverters more efficient because they waste less energy as heat. Higher efficiency and less heat also permit designs that are smaller and lighter. That’s a big deal for electric vehicles, where less weight means less energy consumption.

Kimoto’s second breakthrough was identifying which form of the silicon carbide material would be most useful for electronics applications.

“Silicon carbide is a family with many, many brothers,” Kimoto says, noting that more than 100 variants with different silicon-carbon atomic structures exist.

The 6H-type silicon carbide was the default standard phase used by researchers targeting blue LEDs, but Kimoto discovered that the 4H-type has much better properties for power devices, including high electron mobility. Now all silicon carbide power devices and wafer products are made with the 4H-type.

Silicon carbide power devices in electric vehicles can improve energy efficiency by about 10 percent compared with silicon, Kimoto says. In electric trains, he says, the power required to propel the cars can be cut by 30 percent compared with those using silicon-based power devices.

Challenges remain, he acknowledges. Although silicon carbide power transistors are used in Teslas, other EVs, and electric trains, their performance is still far from ideal because of defects present at the silicon dioxide–SiC interface, he says. The interface defects lower the performance and reliability of MOS-based transistors, so Kimoto and others are working to reduce the defects.

A career sparked by semiconductors

When Kimoto was an only child growing up in Wakayama, Japan, near Osaka, his parents insisted he study medicine, and they expected him to live with them as an adult. His father was a garment factory worker; his mother was a homemaker. His move to Kyoto to study engineering “disappointed them on both counts,” he says.

His interest in engineering was sparked, he recalls, when he was in junior high school, and Japan and the United States were competing for semiconductor industry supremacy.

At Kyoto University, he earned bachelor’s and master’s degrees in electrical engineering, in 1986 and 1988. After graduating, he took a job at Sumitomo Electric Industries’ R&D center in Itami. He worked with silicon-based materials there but wasn’t satisfied with the center’s research opportunities.

He returned to Kyoto University in 1990 to pursue his doctorate. While studying power electronics and high-temperature devices, he also gained an understanding of material defects, breakdown, mobility, and luminescence.

“My experience working at the company was very valuable, but I didn’t want to go back to industry again,” he says. By the time he earned his doctorate in 1996, the university had hired him as a research associate.

He has been there ever since, turning out innovations that have helped make silicon carbide an indispensable part of modern life.

Growing the silicon carbide community at IEEE

Kimoto joined IEEE in the late 1990s. An active volunteer, he has helped grow the worldwide silicon carbide community.

He is an editor of IEEE Transactions on Electron Devices, and he has served on program committees for conferences including the International Symposium on Power Semiconductor Devices and ICs and the IEEE Workshop on Wide Bandgap Power Devices and Applications.

“Now when we hold a silicon carbide conference, more than 1,000 people gather,” he says. “At IEEE conferences like the International Electron Devices Meeting or ISPSD, we always see several well-attended sessions on silicon carbide power devices because more IEEE members pay attention to this field now.”

Earlier this month, China announced that it is pouring 6 billion yuan (about US $826 million) into a fund meant to spur the development of solid-state batteries by the nation’s leading battery manufacturers. Solid-state batteries use electrolytes of either glass, ceramic, or solid polymer material instead of the liquid lithium salts that are in the vast majority of today’s electric vehicle (EV) batteries. They’re greatly anticipated because they will have three or four times as much energy density as batteries with liquid electrolytes, offer more charge-discharge cycles over their lifetimes, and be far less susceptible to the thermal runaway reaction that occasionally causes lithium batteries to catch fire.

But China’s investment in the future of batteries won’t likely speed up the timetable for mass production and use in production vehicles. As IEEE Spectrum pointed out in January, it’s not realistic to look for solid-state batteries in production vehicles anytime soon. Experts Spectrum consulted at the time “noted a pointed skepticism toward the technical merits of these announcements. None could isolate anything on the horizon indicating that solid-state technology can escape the engineering and ‘production hell’ that lies ahead.”

“To state at this point that any one battery and any one country’s investments in battery R&D will dominate in the future is simply incorrect.” —Steve W. Martin, Iowa State University

Reaching scale production of solid-state batteries for EVs will first require validating existing solid-state battery technologies—now being used for other, less demanding applications—in terms of performance, life-span, and relative cost for vehicle propulsion. Researchers must still determine how those batteries take and hold a charge and deliver power as they age. They’ll also need to provide proof that a glass or ceramic battery can stand up to the jarring that comes with driving on bumpy roads and certify that it can withstand the occasional fender bender.

Here Come Semi-Solid-State Batteries

Meanwhile, as the world waits for solid electrolytes to shove liquids aside, Chinese EV manufacturer Nio and battery maker WeLion New Energy Technology Co. have partnered to stake a claim on the market for a third option that splits the difference: semi-solid-state batteries, with gel electrolytes.

CarNewsChina.com reported in April that the WeLion cells have an energy density of 360 watt-hours per kilogram. Fully packaged, the battery’s density rating is 260 Wh/kg. That’s still a significant improvement over lithium iron phosphate batteries, whose density tops out at 160 Wh/kg. In tests conducted last month with Nio’s EVs in Shanghai, Chengdu, and several other cities, the WeLion battery packs delivered more than 1,000 kilometers of driving range on a single charge. Nio says it plans to roll out the new battery type across its vehicle lineup beginning this month.

But the Beijing government’s largesse and the Nio-WeLion partnership’s attempt to be first to get semi-solid-state batteries into production vehicles shouldn’t be a temptation to call the EV propulsion game prematurely in China’s favor.

So says Steve W. Martin, a professor of materials science and engineering at Iowa State University, in Ames. Martin, whose research areas include glassy solid electrolytes for solid-state lithium batteries and high-capacity reversible anodes for lithium batteries, believes that solid-state batteries are the future and that hybrid semi-solid batteries will likely be a transition between liquid and solid-state batteries. However, he says, “to state at this point that any one battery and any one country’s investments in battery R&D will dominate in the future is simply incorrect.” Martin explains that “there are too many different kinds of solid-state batteries being developed right now and no one of these has a clear technological lead.”

The Advantages of Semi-Solid-State Batteries

The main innovation that gives semi-solid-state batteries an advantage over conventional batteries is the semisolid electrolyte from which they get their name. The gel electrolyte contains ionic conductors such as lithium salts just as liquid electrolytes do, but the way they are suspended in the gel matrix supports much more efficient ion conductivity. Enhanced transport of ions from one side of the battery to the other boosts the flow of current in the opposite direction that makes a complete circuit. This is important during the charging phase because the process happens more rapidly than it can in a battery with a liquid electrolyte. The gel’s structure also resists the formation of dendrites, the needlelike structures that can form on the anode during charging and cause short circuits. Additionally, gels are less volatile than liquid electrolytes and are therefore less prone to catching fire.

Though semi-solid-state batteries won’t reach the energy densities and life-spans that are expected from those with solid electrolytes, they’re at an advantage in the short term because they can be made on conventional lithium-ion battery production lines. Just as important, they have been tested and are available now rather than at some as yet unknown date.

Semi-solid-state batteries can be made on conventional lithium-ion battery production lines.

Several companies besides WeLion are actively developing semi-solid-state batteries. China’s prominent battery manufacturers, including CATL, BYD, and the state-owned automakers FAW Group and SAIC Group are, like WeLion, beneficiaries of Beijing’s plans to advance next-generation battery technology domestically. Separately, the startup Farasis Energy, founded in Ganzhou, China, in 2009, is collaborating with Mercedes-Benz to commercialize advanced batteries.

The Road Forward to Solid-State Batteries

U.S. startup QuantumScape says the solid-state lithium metal batteries it’s developing will offer energy density of around 400 Wh/kg. The company notes that its cells eliminate the charging bottleneck that occurs in conventional lithium-ion cells, where lithium must diffuse into the carbon particles. QuantumScape’s advanced batteries will therefore allow fast charging from 10 to 80 percent in 15 minutes. That’s a ways off, but the Silicon Valley–based company announced in March that it had begun shipping its prototype Alpha-2 semi-solid-state cells to manufacturers for testing.

Toyota is among a group of companies not looking to hedge their bets. The automaker, ignoring naysayers, aims to commercialize solid-state batteries by 2027 that it says will give an EV a range of 1,200 km on a single charge and allow 10-minute fast charging. It attributes its optimism to breakthroughs addressing durability issues. And for companies like Solid Power, it’s also solid-state or bust. Solid Power, which aims to commercialize a lithium battery with a proprietary sulfide-based solid electrolyte, has partnered with major automakers Ford and BMW. ProLogium Technology, which is also forging ahead with preparations for a solid-state battery rollout, claims that it will start delivering batteries this year that combine a ceramic oxide electrolyte with a lithium-free soft cathode (for energy density exceeding 500 Wh/kg). The company, which has teamed up with Mercedes-Benz, demonstrated confidence in its timetable by opening the world’s first giga-level solid-state lithium ceramic battery factory earlier this year in Taoyuan, Taiwan.