Such robots would have a long and challenging list of requirements. For example, they would need to survive in bodily fluids, such as stomach acids, and be controllable, so they could be directed precisely to targeted sites. They also must release their medical cargo only when they reach their target, and then be absorbable by the body without causing harm.

Now, microrobots that tick all those boxes have been developed by a Caltech-led team. Using the bots, the team successfully delivered therapeutics that decreased the size of bladder tumors in mice.

A paper describing the work titled “Imaging-guided bioresorbable acoustic hydrogel microrobots” appears in the journal Science Robotics.