We have reported before on robots inspired by insects including cockroach-inspired mighty robots. Scientists it seems are always looking to nature to equip their robots with the skills that insects possess making them formidable tiny machines.
Now, engineers at the University of California, Berkeley, have used the principle behind the specialized sticky footpads that can be seen on spiders to create an insect-scale robot that has the ability to traverse complex terrain and efficiently avoid unexpected obstacles. The principle is called electrostatic adhesion and it makes for a very agile robot that can swerve and pivot with impressive speed and range of motion.
The research team added two electrostatic footpads to the robot and proceeded to apply a voltage to them. This voltage increases the electrostatic force between the footpad and a surface, making that footpad stick more firmly and forcing the rest of the robot to rotate around the foot. This allowed the engineers to better control the robot despite it moving very fast.
"Our original robot could move very, very fast, but we could not really control whether the robot went left or right, and a lot of the time it would move randomly, because if there was a slight difference in the manufacturing process -- if the robot was not symmetrical - it would veer to one side," said Liwei Lin, a professor of mechanical engineering at UC Berkeley. "In this work, the major innovation was adding these footpads that allow it to make very, very fast turns."
The robot is also extremely robust being able to survive being stepped on by a 120-pound human. These types of robots are ideal for conducting search and rescue operations or investigating other dangerous circumstances where humans should not venture.
For these kinds of missions, the researchers demonstrated a battery power-operated version of the tiny robots that could last for up to 19 minutes and 31 meters while carrying a gas sensor.
"One of the biggest challenges today is making smaller scale robots that maintain the power and control of bigger robots," Lin said. "With larger-scale robots, you can include a big battery and a control system, no problem. But when you try to shrink everything down to a smaller and smaller scale, the weight of those elements becomes difficult for the robot to carry and the robot generally moves very slowly. Our robot is very fast, quite strong, and requires very little power, allowing it to carry sensors and electronics while also carrying a battery."
The study is published in ScienceRobotics.