Researchers Design Tiny RoBeetle That’s Powered by Alcohol

Researchers from the University of Southern California's Autonomous Microrobotic Systems Laboratory (AMSL) have developed a tiny autonomous robotic beetle that runs entirely on methanol. What’s more, it can travel for more than two hours on a single tank and carry 2.6 times its body weight (88 milligrams) before needing a refill. Typically, robots are powered by either a battery or tethered to an AC or DC source, which limits how far they can go, or in terms of battery power, how much weight they can carry. The aptly named RoBeetle overcomes those limitations by driving its artificial muscles with liquid fuel.

The robot’s catalytic artificial micro-muscle was made using a nickel-titanium shape-memory alloy (SMA) that shrinks and expands via temperature changes. The muscle is coated with platinum, and when the metal comes in contact with the alcohol, it produces a combustion reaction that creates heat. The small amount of temperature change causes a little vent to slide back and forth, which regulates the fuel flow, driving the robot forward.

RoBeetle can carry 95 milligrams of methanol, which is filled via a fuel-inlet hole using a syringe. The robot is a quadruped with fixed hind legs and a pair of front legs attached to a transmission, which moves them both using a rocking forward motion, followed by a backward and down motion. The transmission is hooked up to a spring that always keeps the legs pulled backward in tension, allowing the robot to stand when it isn’t in motion.

The researchers state that the RoBeetle can be leveraged to fit in spaces too tight for humans to pass through, including search and rescue operations, exploration, and other applications. There are a few challenges to overcome before the robot can be utilized, as it can only move forward at this point, and when it starts walking, it will not stop until it runs out of fuel.