At the resort where the artificial-muscle conference is being held, palm trees lean over redbrick walkways and relaxed tourists mill around in colorful beach clothes. Inside a low-slung building, it´s easy to spot the Swiss team—they´re the anxious-looking engineers talking together in low murmurs. Their device sits on the floor of a conference room. It´s a black fiberglass-composite box. Gabor Kovacs, the team´s lead engineer, has been building dielectric elastomers for five years. His goal is to develop shape-shifting actuators that could be used to, among other things, reduce wind resistance in blimps. But lab tests on the material only go so far; last year he took up the arm-wrestling challenge.“We wanted to see the possibilities and limits of this technology,” he says.
After consulting biomechanics texts, Kovacs and his team, who work for a government lab, decided to simulate the torso muscles an arm wrestler uses by rotating the entire robot (the black box) around an axle (a stand-in for the shoulder joint) while holding the“arm” stiff. To make their actuators, they built a machine that stretches a sheet of silicone and sprays it on both sides with a chemical coating. The machine then wraps this three-layer film, a dielectric elastomer, around a springy steel core. To maximize the actuators´ power, the team spent months experimenting with various chemical formulations of the coating.
This afternoon, a day before the match, Kovacs expounds on his masterpiece. It took a year to build, he tells me, and cost $250,000 in Swiss government funds. It possesses 256 actuators, powered by up to 4,000 volts. But before he can finish, two young men appear. They confer in German, glancing unsmilingly at the arm ´bot. As they pick it up and prepare to leave, the only words I understand are“Home Depot.”single page
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.