New 'liquibots' are the first ever to work without any electricity

Researchers from the Department of Energy's Lawrence Berkeley National Laboratory and the University of Massachusetts Amherst were responsible for the breakthrough.

The two-millimeter wide, self-powered aqueous robots, dubbed 'liquibots,' can deliver chemicals while partially submerged in a solution. They can potentially be used for drug delivery in pharmaceutical applications or as part of an automated chemical synthesis framework.

Previous liquibots have been made but could only carry out an autonomous task once, only able to continue indefinitely with electricity. These new liquibots can harvest the energy they need to continue working from the chemicals in their environment.

"We have broken a barrier in designing a liquid robotic system that can operate autonomously by using chemistry to control an object's buoyancy," said senior author Tom Russell, a professor of polymer science and engineering from the University of Massachusetts Amherst.

The liquibots absorb salt to become heavier than the solution they are immersed in, causing them to cluster together in the center and fill up with certain chemicals. This leads to a reaction within the liquibots that produces oxygen bubbles, making them more buoyant and carrying them to the edges of the fluid to deposit the chemicals they are carrying, repeating this process until the chemical fuel in the immediate environment is used up.

You can read more from the team's study here.