This tiny robotic beetle travels for two hours without a battery

A team of researchers from the University of Southern California have created a miniscule autonomous robotic beetle, RoBeetle, that can travel for more than two hours without a battery. The 88-milligram, insect-inspired robot runs on liquid methanol, which powers its artificial muscles, and it can carry payloads 2.6 times its own body weight. As you may know, 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.