You know how balloons can stick to walls after rubbing them on your clothes or carpet? That's exactly how the upgraded RoboBee sticks to surfaces. The engineers attached a shock-absorbing foam and an electrode patch on top of the machine. This patch's negative charge pushes some of the surface's electrons away, and when that happens, the robot can stick to it. To keep the charge from disappearing and the robot from falling off, the patch emits a continuous supply of energy.

Harvard says the robot uses 1,000 times less power when it's attached to something than when it's hovering, fulfilling the engineers' goal of extending its battery life. The system is far from being perfect, though. It can only attach RoboBee to ceilings or the underside of structures like tables, leaves or open windows, and it doesn't stick as well to rough or uneven surfaces. The team plans to tweak it further so that RoboBee can vertically perch on walls of any texture. For now, they published their experiment and findings on Science and demoed their work in the video below.