Microrobots powered by their environment

Researchers in the United States have developed autonomous microscopic robots that can move and react to their environment using light. These tiny machines are promising for medical and scientific applications because of their small size and low cost.

Limitations of traditional power sources

Despite their potential, microrobots are limited by their lack of autonomy. A conventional battery on a 1.7-gram robot would only last a few minutes. To achieve two hours of operation, the battery would need to make up 94% of the robot's weight.

Innovative power solution from China

Researchers at Fudan University in China proposed a new way to power microrobots by using the environment itself as a power source. In an article published in the National Science Review, they described a device that generates energy through a membrane on the robot's feet.

How the membrane generates energy

The membrane is made of a potassium polyacrylate polymer applied directly to the robot's feet. It is paired with a film of platinum and carbon that reacts with water and oxygen. When placed on a substrate like aluminum, zinc, or silicon, the robot can generate energy through a chemical reaction that produces hydroxide ions.

Additional capabilities of the membrane

The membrane also allows the robot to sense the type of surface it is on and prevents it from slipping. This stickiness enables the robot to climb inclined surfaces, although it cannot generate power on surfaces like soil, plastic, or glass.

Overcoming power limitations

To address these limitations, the researchers added a supercapacitor to the robot, allowing it to move through areas where it cannot generate power. This innovation means microrobots can operate with greater autonomy without relying on heavy batteries, though their usable environments are still somewhat limited.