"A technology pioneered by Benjamin Franklin is being revived to build more efficient electric motors,"
reports the Wall Street Journal, "an effort in its nascent stage that has the potential to be massive."
A handful of scientists and engineers — armed with materials and techniques unimaginable in the 1700s — are creating modern versions of Franklin's "electrostatic motor," that are on the cusp of commercialization... Franklin's "electrostatic motor" uses alternating positive and negative charges — the same kind that make your socks stick together after they come out of the dryer — to spin an axle, and doesn't rely on a flow of current like conventional electric motors. Every few years, an eager Ph.D. student or engineer rediscovers this historical curiosity. But other than applications in tiny pumps and actuators etched on microchips, where this technology has been in use for decades, their work hasn't made it out of the lab.
Electrostatic motors have several potentially huge advantages over regular motors. They are up to 80% more efficient than conventional motors after all the dependencies of regular electric motors are added in. They could also allow new kinds of control and precision in robots, where they could function more like our muscles. And they don't use rare-earth elements because they don't have permanent magnets, and require as little as 5% as much copper as a conventional motor. Both materials have become increasingly scarce and expensive over the past decade, and supply chains for them are dominated by China.
"It's reminiscent of the early 1990s, when Sony began to produce and sell the first rechargeable lithium-ion batteries, a breakthrough that's now ubiquitous..." according to the article. "These motors could lead to more efficient air-conditioning systems, factories, logistics hubs and data centers, and — since they can double as generators — better ways of generating renewable energy. They might even show up in tiny surveillance drones."
And the article points out that C-Motive Technologies, a 16-person startup in Wisconsin, is already "reaching out to companies, hoping to get their motors out into the real world." ("So far, FedEx and Rockwell Automation, the century-old supplier of automation to factories, are among those testing their motors.")
C-Motive's founders discovered that a number of technologies had matured enough that, when combined, could yield electrostatic motors competitive with conventional ones. These enabling technologies include super fast-switching power electronics — like those in modern electric vehicles — that can toggle elements of the motor between states of positive and negative charge very quickly... Dogged exploration of combinations of various readily available industrial organic fluids led to a proprietary mix that can both multiply the strength of the electric field and insulate the motor's spinning parts from each other — all without adding too much friction — says C-Motive Chief Executive Matt Maroon.