Tiny robots can jump, swim, and move exactly where needed using bubbles. This new way could change medicine, machines, and small device repairs.
A team of scientists from China and the U.S. have developed bubble-powered robots that could one day deliver drugs into the body without needles. They created a method that uses energy from collapsing bubbles in liquid, a process called cavitation, to propel tiny robots. In tests, these millimeter-sized devices were launched 1.5 meters into the air at takeoff speeds exceeding 12 meters per second.
The robots are made from titanium dioxide, polypyrrole, and titanium carbide. They heat up quickly when hit by a laser, triggering bubble formation and collapse in the surrounding liquid. The rapid release of energy during cavitation generates bursts of power and acceleration, giving the devices high kinetic energy.
Researchers demonstrated that the launch direction and distance can be precisely controlled by adjusting where the laser strikes the device. The mechanism is not limited to lasers; it can also be triggered by ultrasound or an electrical spark. The team also created “swimmers” capable of moving on water at 12 centimeters per second. Compared to traditional spring-based systems, this approach allows faster energy release and greater versatility.
While the jumpers are still a proof-of-concept far from practical drug delivery in the human body, challenges remain, such as controlling cavitation in complex environments and ensuring material biocompatibility.
Beyond medicine, the technology could have broader applications, including precise assembly of tiny parts in electronics and biomedical devices, and inspecting or repairing pipelines and machinery in confined spaces.
Once considered a destructive force, cavitation is now being harnessed to power a new generation of micro-robots.
