This is some seriously cool research. Scientists at the EPFL (Ecole Polytechnique Federale de Lausanne) have made tiny, tiny, tiny robots using shape memory alloys, or SMA’s for short. They weigh less than 4 grams and move like an inchworm!
Unlike regular robots that feature rigid structures and electric actuators, the researchers opted to take more of an origami like approach — so much so, they call it robogami. Their very first attempt was years ago, and was rather large. Since then they’ve shrunk it down to about the size of a compact flash card. The way it works is quite simple. SMA’s shrink when heated (either externally heated or by an internal current) and in doing so, produce extremely high forces.
So by patterning these in a shape (like that of an inchworm) the researchers are able to trigger each “limb” separately to induce movement. They can also jump seven times their height thanks to the super high power-density of SMA’s.
SMA’s are available to the public, but sadly we haven’t seen many hacks that make use of them.