Lucid Motors has officially started taking orders for its electric Gravity SUV, a critically important vehicle that’s supposed to go into production by the end of this year. Interested buyers can now place $1,000 refundable deposits on the “Grand Touring” trim, which starts at $94,900, on the company’s website. Similar to the company’s current model, […]
General Motors CEO Mary Barra still believes an autonomous vehicle with no steering wheel and pedals is “definitely” in her company’s future, despite recently suspending work on the purpose-built Origin. Barra told the crowd at TechCrunch Disrupt 2024 on Tuesday that she still has an eye on a robotaxi with no steering wheel but that […]
NASHVILLE, Tenn.—Today, the reborn Scout Motors showed off a pair of new electric vehicles that revives the long-dormant maker of trucks and SUVs. Originally owned by International Harvester, Scout now belongs to Volkswagen Group, which decided to use it to create a new American-made brand for off-road-capable vehicles.
The first of these will be the Traveler SUV and Terra pickup truck, due to go into production in 2027. Despite VW's recent investment in Rivian, these are all-new, clean-sheet designs with a platform unique to Scout designed in Michigan, a platform that uses a body-on-frame construction with either purely electric or range-extended powertrains.
Scout says that pricing for the Terra and Traveler should start at "under $60,000," or "as low as $50,000 with available incentives" for the entry-level models, which are due to go into production at a new factory north of Columbia, South Carolina, in 2027.
It’s a pretty sure bet that you couldn’t get through a typical day without the direct support of dozens of electric motors. They’re in all of your appliances not powered by a hand crank, in the climate-control systems that keep you comfortable, and in the pumps, fans, and window controls of your car. And although there are many different kinds of electric motors, every single one of them, from the 200-kilowatt traction motor in your electric vehicle to the stepper motor in your quartz wristwatch, exploits the exact same physical phenomenon: electromagnetism.
For decades, however, engineers have been tantalized by the virtues of motors based on an entirely different principle: electrostatics. In some applications, these motors could offer an overall boost in efficiency ranging from 30 percent to close to 100 percent, according to experiment-based analysis. And, perhaps even better, they would use only cheap, plentiful materials, rather than the rare-earth elements, special steel alloys, and copious quantities of copper found in conventional motors.
“Electrification has its sustainability challenges,” notes Daniel Ludois, a professor of electrical engineering at the University of Wisconsin in Madison. But “an electrostatic motor doesn’t need windings, doesn’t need magnets, and it doesn’t need any of the critical materials that a conventional machine needs.”
Such advantages prompted Ludois to cofound a company, C-Motive Technologies, to build macro-scale electrostatic motors. “We make our machines out of aluminum and plastic or fiberglass,” he says. Their current prototype is capable of delivering torque as high as 18 newton meters and power at 360 watts (0.5 horsepower)—characteristics they claim are “the highest torque and power measurements for any rotating electrostatic machine.”
The results are reported in a paper, “Synchronous Electrostatic Machines for Direct Drive Industrial Applications,” to be presented at the 2024 IEEE Energy Conversion Congress and Exposition, which will be held from 20 to 24 October in Phoenix, Ariz. In the paper, Ludois and four colleagues describe an electrostatic machine they built, which they describe as the first such machine capable of “driving a load performing industrial work, in this case, a constant-pressure pump system.”
Making Electrostatic Motors Bigger
The machine, which is hundreds of times more powerful than any previous electrostatic motor, is “competitive with or superior to air-cooled magnetic machinery at the fractional [horsepower] scale,” the authors add. The global market for fractional horsepower motors is more than US $8.7 billion, according to consultancy Business Research Insights.
C-Motive’s 360-watt motor has a half dozen each of rotors and stators, shown in yellow in this cutaway illustration.C-Motive Technologies
Achieving macro scale wasn’t easy. Electrostatic motors have been available for years, but today, these are tiny units with power output measured in milliwatts. “Electrostatic motors are amazing once you get below about the millimeter scale, and they get better and better as they get smaller and smaller,” says Philip Krein, a professor of electrical engineering at the University of Illinois Urbana-Champaign. “There’s a crossover at which they are better than magnetic motors.” (Krein does not have any financial connection to C-Motive.)
For larger motors, however, the opposite is true. “At macro scale, electromagnetism wins, is the textbook answer,” notes Ludois. “Well, we’ve decided to challenge that wisdom.”
For this quest he and his team found inspiration in a lesser-known accomplishment of one of the United States’ founding fathers. “The fact is that Benjamin Franklin built and demonstrated a macroscopic electrostatic motor in 1747,” says Krein. “He actually used the motor as a rotisserie to grill a turkey on a riverbank in Philadelphia” (a fact unearthed by the late historian I. Bernard Cohen for his 1990 book Benjamin Franklin’s Science ).
Krein explains that the fundamental challenge in attempting to scale electrostatic motors to the macro world is energy density. “The energy density you can get in air at a reasonable scale with an electric-field system is much, much lower—many orders of magnitude lower—than the density you can get with an electromagnetic system.” Here the phrase “in air” refers to the volume within the motor, called the “air gap,” where the machine’s fields (magnetic for the conventional motor, electric for the electrostatic one) are deployed. It straddles the machine’s key components: the rotor and the stator.
Let’s unpack that. A conventional electric motor works because a rotating magnetic field, set up in a fixed structure called a stator, engages with the magnetic field of another structure called a rotor, causing that rotor to spin. The force involved is called the Lorentz force. But what makes an electrostatic machine go ‘round is an entirely different force, called the Coulomb force. This is the attractive or repulsive physical force between opposite or like electrical charges.
Overcoming the Air Gap Problem
C-Motive’s motor uses nonconductive rotor and stator disks on which have been deposited many thin, closely spaced conductors radiating outward from the disk’s center, like spokes in a bicycle wheel. Precisely timed electrostatic charges applied to these “spokes” create two waves of voltage, one in the stator and another in the rotor. The phase difference between the rotor and stator waves is timed and controlled to maximize the torque in the rotor caused by this sequence of attraction and repulsion among the spokes. To further wring as much torque as possible, the machine has half a dozen each of rotors and stators, alternating and stacked like compact discs on a spindle.
The 360-watt motor is hundreds of times more powerful than previous electrostatic motors, which have power output generally measured in milliwatts.C-Motive Technologies
The machine would be feeble if the dielectric between the charges was air. As a dielectric, air has low permittivity, meaning that an electric field in air can not store much energy. Air also has a relatively low breakdown field strength, meaning that air can support only a fairly weak electric field before it breaks down and conducts current in a blazing arc. So one of the team’s greatest challenges was producing a dielectric fluid that has a much higher permittivity and breakdown field strength than air, and that was also environmentally friendly and nontoxic. To minimize friction, this fluid also had to have very low viscosity, because the rotors would be spinning in it. A dielectric with high permittivity concentrates the electric field between oppositely charged electrodes, enabling greater energy to be stored in the space between them. After screening hundreds of candidates over several years, the C-Motive team succeeded in producing an organic liquid dielectric with low viscosity and a relative permittivity in the low 20s. For comparison, the relative permittivity of air is 1.
Another challenge was supplying the 2,000 volts their machine needs to operate. High voltages are necessary to create the intense electric fields between the rotors and stators. To precisely control these fields, C-Motive was able to take advantage of the availability of inexpensive and stupendously capable power electronics, according to Ludois. For their most recent motor, they developed a drive system based on readily available 4.5-kilovolt insulated-gate bipolar transistors, but the rate of advancement in power semiconductors means they have many attractive choices here, and will have even more in the near future.
Ludois reports that C-Motive is now testing a 750-watt (1 hp) motor in applications with potential customers. Their next machines will be in the range of 750 to 3,750 watts (1 to 5 hp), he adds. These will be powerful enough for an expanded range of applications in industrial automation, manufacturing, and heating, ventilating, and air conditioning.
It’s been a gratifying ride for Ludois. “For me, a point of creative pride is that my team and I are working on something radically different that, I hope, over the long term, will open up other avenues for other folks to contribute.”
A French cycling official confronts a rider suspected of doping and ends up jumping onto the hood of a van making a high-speed getaway. This isn’t a tragicomedy starring Gérard Depardieu, sending up the sport’s well-earned reputation for cheating. This scenario played out in May at the Routes de l’Oise cycling competition near Paris, and the van was believed to contain evidence of a distinctly 21st-century cheat: a hidden electric motor.
Cyclists call it “motor doping.” At the Paris Olympics opening on Friday, officials will be deploying electromagnetic scanners and X-ray imaging to combat it, as cyclists race for gold in and around the French capital. The officials’ prey can be quite small: Cycling experts say just 20 or 30 watts of extra power is enough to tilt the field and clinch a race.
Motor doping has been confirmed only once in professional cycling, way back in 2016. And the sport’s governing body, the Union Cycliste Internationale (UCI), has since introduced increasingly sophisticated motor-detection methods. But illicit motors remain a scourge at high-profile amateur events like the Routes de l’Oise. Some top professionals, past and present, continue to raise an alarm.
“It’s 10 years now that we’re speaking about this…. If you want to settle this issue you have to invest.” —Jean-Christophe Péraud, former Union Cycliste Internationale official
Riders and experts reached by IEEE Spectrum say it’s unlikely that technological doping still exists at the professional level. “I’m confident it’s not happening any more. I think as soon as we began to speak about it, it stopped. Because at a high level it’s too dangerous for a team and an athlete,” says Jean-Christophe Péraud, an Olympic silver medalist who was UCI’s first Manager of Equipment and the Fight against Technological Fraud.
Many—including Péraud—say more vigilance is needed. The solution may be next-generation detection tech: onboard scanners that provide continuous assurance that human muscle alone is powering the sport’s dramatic sprints and climbs.
How Officials Have Hunted for Motor Doping in Cycling
Rumors of hidden motors first swirled into the mainstream in 2010 after a Swiss cyclist clinched several European events with stunning accelerations. At the time the UCI lacked means of detecting concealed motors, and its technical director promised to “speed up” work on a “quick and efficient way” to do so.
The UCI began with infrared cameras, but they are useless for pre- and post-race checks when a hidden motor is cold. Not until 2015, amidst further motor doping rumors and allegations of UCI inaction, did the organization begin beta testing a better tool: an iPad-based “magnetometric tablet” scanner.
According to the UCI, an adapter plugged into one of these tablet scanners creates an ambient magnetic field. Then, a magnetometer and custom software register disruptions to the field that may indicate the presence of metal or magnets in and around a bike’s carbon-fiber frame.
UCI’s tablets delivered in their debut appearance, at the 2016 Cyclocross World Championships held that year in Belgium. Scans of bikes at the rugged event—a blend of road and mountain biking—flagged a bike bearing the name of local favorite Femke Van den Driessche. Closer inspection revealed a motor and battery lodged within the hollow frame element that angles down from a bike’s saddle to its pedals, and wires connecting the seat tube’s hidden hardware to a push-button switch under the handlebars.
In 2016, a concealed motor was found in a bike bearing Belgian cyclist Femke Van Den Driessche’s name at the world cyclo-cross championships. (Van Den Driessche is shown here with a different bike.)AFP/Getty Images
Van den Driessche, banned from competition for six years, withdrew from racing while maintaining her innocence. (Giovambattista Lera, the amateur cyclist implicated earlier this year in France, also denies using electric assistance in competition.)
The motor in Van den Driessche’s bike engaged with the bike’s crankshaft and added 200 W of power. The equipment’s Austrian manufacturer, Vivax Drive, is now defunct. But anyone with cash to spare can experience 200 W of extra push via a racer equipped by Monaco-based HPS-Bike, such as the HPS-equipped Lotus Type 136 racing bike from U.K. sports car producer Lotus Group, which starts at £15,199 (US $19,715).
HPS founder & CEO Harry Gibbings says the company seeks to empower weekend riders who don’t want to struggle up steep hills or who need an extra boost here and there to keep up with the pack. Gibbings says the technology is not available for retrofits, and is thus off limits to would-be cheats. Still, the HPS Watt Assist system shows the outer bounds of what’s possible in discreet high-performance electric assist.
The 30-millimeter-diameter, 300-gram motor, is manufactured by Swiss motor maker Maxon Group, and Gibbings says it uses essentially the same power-dense brushless design that’s propelling NASA’s Perseverance rover on Mars. HPS builds the motor into a bike’s downtube, the frame element angling up from a bike’s crank toward its handlebars.
Notwithstanding persistent media speculation about electric motors built into rear hubs or solid wheels, Gibbings says only a motor placed in a frame’s tubes can add power without jeopardizing the look, feel, and performance of a racing bike.
UCI’s New Techniques to Spot Cheating in Cycling
Professional cycling got its most sophisticated detection systems in 2018, after criticism of UCI motor-doping policies helped fuel a change of leadership. Incoming President David Lappartient appointed Péraud to push detection to new levels, and five months later UCI announced its first X-ray equipment at a press conference in Geneva.
Unlike the tablet scanners, which yield many false positives and require dismantling of suspect bikes, X-ray imaging is definitive. The detector is built into a shielded container and driven to events.
UCI told the cycling press that its X-ray cabinet would “remove any suspicion regarding race results.” And it says it maintains a high level of testing, with close to 1,000 motor-doping checks at last year’s Tour de France.
UCI declined to speak with IEEE Spectrum about its motor-detection program, including plans for the Paris Olympics. But it appears to have stepped up vigilance. Lappartient recently acknowledged that UCI’s controls are “not 100 percent secure” and announced a reward for whistleblowers who deliver evidence of motor fraud. In May, UCI once again appointed a motor-doping czar—a first since Péraud departed amidst budget cuts in 2020. Among other duties, former U.S. Department of Homeland Security criminal investigator Nicholas Raudenski is tasked with “development of new methods to detect technological fraud.”
Unlike the tablet scanners, X-ray imaging is definitive.
Péraud is convinced that only real-time monitoring of bikes throughout major races can prove that motor fraud is in the past, since big races provide ample opportunities to sneak in an additional bike and thus evade UCI’s current tools.
UCI has already laid the groundwork for such live monitoring, partnering with France’s Alternative Energies and Atomic Energy Commission (Commissariat à l’énergie atomique et aux énergies alternatives, or CEA) to capitalize on the national lab’s deep magnetometry expertise. UCI disclosed some details at its 2018 Geneva press conference, where a CEA official presented its concept: an embedded, high-resolution magnetometer to detect a hidden motor’s electromagnetic signature and wirelessly alert officials via receivers on race support vehicles.
As of June 2018, CEA researchers in Grenoble had identified an appropriate magnetometer and were evaluating the electromagnetic noise that could challenge the system—“from rotating wheels and pedals to passing motorcycles and cars.”
Mounting detectors on every bike would not be cheap, but Péraud says he is convinced that cycling needs it: “It’s 10 years now that we’re speaking about this…. If you want to settle this issue you have to invest.”
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