Scientists at Northwestern University in Illinois have built the world’s smallest laser-guided crab robot, measuring just 0.5 mm in length. These little ones can bend, walk, crawl, spin and jump without the help of electricity or hydraulics. And all because they consist of materials with a shape memory effect. Heating makes it spread and makes it flat, and the thinnest glass coating returns the body of the bot to its original state when cooled.
Heating takes place with the help of a laser. In which direction to hold the laser, in this direction the movement occurs – the beam moves to the left, and the crabs jump to the left. The speed of movement is about half the length of the crab per second. The scientists also decided to play with geometry and created three-legged bugs that can float on water and rotate around their axis, and spiral octopuses that make small jumps.
The robots were initially assembled flat – this is their state in heating. A stretched rubber base was glued around the perimeter of the base, which was then loosened, which led to a decrease in its area, and then the robots took the final “standing” shape, and an additional glass coating was applied to secure it.
Why crabs? The assembly method and materials make it possible to create crawling robots of almost any shape and size. But the students were amused by watching the miniature crabs crawl in different directions. So the developers assure that it was more of a creative fantasy.