The robots themselves are only 5 microns thick, 40 microns wide and between 40 and 70 microns long, depending on the design. The brain and body are made up of a photovoltaic circuit, while the legs are made up of a quartet of electrochemical actuators.
“In the context of the robot’s brain, there’s a meaning in which we simply take existing semiconductor technology and make it small and releasable,” McEuen said. Cornell News. “But the legs did not exist before. There were no small, electrically activatable actuators you could use. We had to invent that and then combine it with the electronics. ”
Cornell University
The legs are layers of atomically dense strips of platinum with a titanium ‘cap’ that ends the end. When the platinum is exposed to an electric charge, negatively charged ions absorb the surrounding chemical solution on the platinum surface to neutralize the charge. That uptake causes the platinum leg to bend, although it is thin enough not to break under the stress of repeated bending. To encourage the robot to actually move, the team blows the photovoltaics into its body with laser pulses. Each set of pulses is directed to a separate circuit which in turn controls a separate set of legs.
“Although these robots are primitive in their function – they are not very fast, they do not have much computational power – the innovations we have made to make them compatible with standard microchip manufacturing open the door to make these microscopic robots smart, fast and mass-produced, “noted Cohen.” This is really just the first shot over the bow that, hey, we can do electronic integration on a small robot. “
And because they are built using the same production method as semiconductors do, they can be mass-produced in the same way that semiconductors are. Parallel and on the tune of roughly 1 million robots per 4-inch silicone wafer. The team looks forward to a day when swarms of these robots will swim through your body fluids, remove spots, repair blood vessels, even examine in your gray matter.
‘Checking a small robot is perhaps as close as you can get to shrinking yourself. I think machines like these will take us into all sorts of great worlds that are too small to see, ”Miskin concluded.
