A team of researchers from the University of Southern California have created a miniscule autonomous robot, RoBeetle, which can travel for more than two hours without a battery.

The 88-milligram, robot runs on liquid methanol, which powers its artificial muscles, and it can carry payloads 2.6 times its own body weight.

Batteries have low-energy density, meaning in order to store lots of energy, they need to be pretty big. That’s a problem for microrobots, and it’s one reason that tiny bots, like Harvard’s penny-sized HAMR-JR, are often tethered to power sources. The fact that RoBeetle doesn’t need a battery means it can be ultra-tiny and crawl around untethered.

The system’s “catalytic artificial micro-muscle” is made with a nickel-titanium shape-memory alloy, a wire that shrinks and expands with temperature changes. That wire is coated with platinum, and when the platinum interacts with RoBeetle’s methanol fuel, a combustion reaction generates heat. The temperature changes cause a tiny vent to slide back and forth, regulating the fuel flow and causing RoBeetle to propel forward.(SD-Agencies)