May 26 (UPI) -- A team of Northwestern University engineers announced the invention of the world's smallest remote-controlled walking robot, which measures only one-half millimeter wide.
The engineers said in research published in the journal Science Robotics that their crab-like robot is smaller than the thickness of a penny.
John A. Rogers, an engineering professor at the Evanston, Ill., school and co-author of the research study, said it took his team a year and a half to develop the tiny robots.
The robots can walk, twist, turn and jump. They are made of a malleable shape-memory alloy, which moves by changing shape when heat is applied. Rogers said the necessary heat comes from lasers.
"A laser is a convenient way to do it because we can focus the light to a very tiny spot, and we can scan that spot around to illuminate different parts of the robot's body in a time sequence," Rogers told CNN.
He said the robots could be used eventually for surgical purposes or making repairs to small-scale machines.