Scientists have created swarms of tiny, non-mechanical robots out of bubbles that they control with nothing more than an infrared laser. The bubblebots were used, for example, to move around glass beads in a dish to spell the letters “U” and “H” for University of Hawaii, where the concept was developed by researchers in Aaron Ohta's lab. They've also been used to move live yeast cells encased in hydrogel blocks, linking together a puzzle-like chain. To move the bubble robots, controllers shine a laser through the bubble, which generates a force. The bubble follows the position of the laser; its velocity corresponds to the intensity of the light. For a more technical description, read IEEE's post on the technology. The key advantage to such a control mechanism is the potential to independently move around individual bubbles in a swarm of microbots with simplicity. Other researchers have achieved independent motion in robot swarms via slightly different construction of the robots, allowing for slightly different motion when they respond to a signal, or sophisticated algorithms. Less sophisticated microbot swarms all respond the same to a signal, such as magnetically steered robots that all go in the same direction as the magnetic field. The laser control opens new possibilities, IEEE explains: “Eventually, it may be possible to conjure swarms of microscopic bubble robots out of nothing, set them to work building microstructures with an array of thermal lasers, and then when they're finished, give each one a little pop to wipe it completely out of existence without any mess or fuss.”
