Imagine you’re a baby cocoa plant, just unfurling your first tentative roots into the fertile, welcoming soil.

Somewhere nearby, a predator stirs. It has no ears to hear you, no eyes to see you. But it knows where you are, thanks in part to the weak electric field emitted by your roots.

It is microscopic, but it’s not alone. By the thousands, the creatures converge, slithering through the waterlogged soil, propelled by their flagella. If they reach you, they will use fungal-like hyphae to penetrate and devour you from the inside. They’re getting closer. You’re a plant. You have no legs. There’s no escape.

But just before they fall upon you, they hesitate. They seem confused. Then, en masse, they swarm off in a different direction, lured by a more attractive electric field. You are safe. And they will soon be dead.

If Eleonora Moratto and Giovanni Sena get their way, this is the future of crop pathogen control.

Many variables are involved in the global food crisis, but among the worst are the pests that devastate food crops, ruining up to 40 percent of their yield before they can be harvested. One of these—the little protist in the example above, an oomycete formally known as Phytophthora palmivora—has a US $1 billion appetite for economic staples like cocoa, palm, and rubber.

There is currently no chemical defense that can vanquish these creatures without poisoning the rest of the (often beneficial) organisms living in the soil. So Moratto, Sena, and their colleagues at Sena’s group at Imperial College London settled on a non-traditional approach: They exploited P. palmivora’s electric sense, which can be spoofed.

All plant roots that have been measured to date generate external ion flux, which translates into a very weak electric field. Decades of evidence suggests that this signal is an important target for predators’ navigation systems. However, it remains a matter of some debate how much their predators rely on plants’ electrical signatures to locate them, as opposed to chemical or mechanical information. Last year, Moratto and Sena’s group found that P. palmivora spores are attracted to the positive electrode of a cell generating current densities of 1 ampere per square meter. “The spores followed the electric field,” says Sena, suggesting that a similar mechanism helps them find natural bioelectric fields emitted by roots in the soil.

That got the researchers wondering: Might such an artificial electric field override the protists’ other sensory inputs, and scramble their compasses as they tried to use plant roots’ much weaker electrical output?

To test the idea, the researchers developed two ways to protect plant roots using a constant vertical electric field. They cultivated two common snacks for P. palmivora—a flowering plant related to cabbage and mustard, and a legume often used as a livestock feed plant—in tubes in a hydroponic solution.

Two electric-field configurations were tested: A “global” vertical field [left] and a field generated by two small nearby electrodes. The global field proved to be slightly more effective.Eleonora Moratto

In the first assay, the researchers sandwiched the plant roots between rows of electrodes above and below, which completely engulfed them in a “global” vertical field. For the second set, the field was generated using two small electrodes a short distance away from the plant, creating current densities on the order of 10 A/m². Then they unleashed the protists.

With respect to the control group, both methods successfully diverted a significant portion of the predators away from the plant roots. They swarmed the positive electrode, where—since zoospores can’t survive for longer than about 2 to 3 hours without a host—they presumably starved to death. Or worse. Neil Gow, whose research presented some of the first evidence for zoospore electrosensing, has other theories about their fate. “Applied electrical fields generate toxic products and steep pH gradients near and around the electrodes due to the electrolysis of water,” he says. “The tropism towards the electrode might be followed by killing or immobilization due to the induced pH gradients.”

Not only did the technique prevent infestation, but some evidence indicates that it may also mitigate existing infections. The researchers published their results in August in Scientific Reports.

The global electric field was marginally more successful than the local. However, it would be harder to translate from lab conditions into a (literal) field trial in soil. The local electric field setup would be easy to replicate: “All you have to do is stick the little plug into the soil next to the crop you want to protect,” says Sena.

Moratto and Sena say this is a proof of concept that demonstrates a basis for a new, pesticide-free way to protect food crops. (Sena likens the technique to the decoys used by fighter jets to draw away incoming missiles by mimicking the signals of the original target.) They are now looking for funding to expand the project. The first step is testing the local setup in soil; the next is to test the approach on Phytophthora infestans, a meaner, scarier cousin of P. palmivora.

P. infestans attacks a more varied diet of crops—you may be familiar with its work during the Irish potato famine. The close genetic similarities imply another promising candidate for electrical pest control. This investigation, however, may require more funding. P. infestans research can be undertaken only under more stringent laboratory security protocols.

The work at Imperial ties into the broader—and somewhat charged—debate around electrostatic ecology; that is, the extent to which creatures including ticks make use of heretofore poorly understood electrical mechanisms to orient themselves and in other ways enhance their survival. “Most people still aren’t aware that naturally occurring electricity can play an ecological role,” says Sam England, a behavioral ecologist with Berlin’s Natural History Museum. “So I suspect that once these electrical phenomena become more well known and understood, they will inspire a greater number of practical applications like this one.”

Over the past 20 years, technological advances have enabled inventors to go from strength to strength. And yet, according to the legendary inventor Dean Kamen, innovation has stalled. Kamen made a name for himself with inventions including the first portable insulin pump for diabetics, an advanced wheelchair that can climb steps, and the Segway mobility device. Here, he talks about his plan for enabling innovators.

How has inventing changed since you started in the 1990s?

Dean Kamen: Kids all over the world can now be inventing in the world of synthetic biology the way we played with Tinkertoys and Erector Sets and Lego. I used to put pins and smelly formaldehyde in frogs in high school. Today in high school, kids will do experiments that would have won you the Nobel Prize in Medicine 40 years ago. But none of those kids are likely in any short time to be on the market with a pharmaceutical that will have global impact. Today, while invention is getting easier and easier, I think there are some aspects of innovation that have gotten much more difficult.

Can you explain the difference?

Kamen: Most people think those two words mean the same thing. Invention is coming up with an idea or a thing or a process that has never been done that way before. [Thanks to] more access to technology and 3D printers and simulation programs and virtual ways to make things, the threshold to be able to create something new and different has dramatically lowered.

Historically, inventions were only the starting point to get to innovation. And I’ll define an innovation as something that reached a scale where it impacted a piece of the world, or transformed it: the wheel, steam, electricity, Internet. Getting an invention to the scale it needs to be to become an innovation has gotten easier—if it’s software. But if it’s sophisticated technology that requires mechanical or physical structure in a very competitive world? It’s getting harder and harder to do due to competition, due to global regulatory environments.

[For example,] in proteomics [the study of proteins] and genomics and biomedical engineering, the invention part is, believe it or not, getting a little easier because we know so much, because there are development platforms now to do it. But getting a biotech product cleared by the Food and Drug Administration is getting more expensive and time consuming, and the risks involved are making the investment community much more likely to invest in the next version of Angry Birds than curing cancer.

A lot of ink has been spilled about how AI is changing inventing. Why hasn’t that helped?

Kamen: AI is an incredibly valuable tool. As long as the value you’re looking for is to be able to collect massive amounts of data and being able to process that data effectively. That’s very different than what a lot of people believe, which is that AI is inventing and creating from whole cloth new and different ideas.

How are you using AI to help with innovation?

Kamen: Every medical school has incredibly brilliant professors and grad students with petri dishes. “Look, I can make nephrons. We can grow people a new kidney. They won’t need dialysis.” But they only have petri dishes full of the stuff. And the scale they need is hundreds and hundreds of liters.

I started a not-for-profit called ARMI—the Advanced Regenerative Manufacturing Institute—to help make it practical to manufacture human cells, tissues, and organs. We are using artificial intelligence to speed up our development processes and eliminate going down frustratingly long and expensive [dead-end] paths. We figure out how to bring tissue manufacturing to scale. We build the bioreactors, sensor technologies, robotics, and controls. We’re going to put them together and create an industry that can manufacture hundreds of thousands of replacement kidneys, livers, pancreases, lungs, blood, bone, you name it.

So ARMI’s purpose is to help would-be innovators?

Kamen: We are not going to make a product. We’re not even going to make a whole company. We’re going to create baseline core technologies that will enable all sorts of products and companies to emerge to create an entire new industry. It will be an innovation in health care that will lower costs because cures are much cheaper than chronic treatments. We have to break down the barriers so that these fantastic inventions can become global innovations.

This article appears in the November 2024 print issue as “The Inventor’s Inventor.”