Tiny, untethered instruments like these microrobots may one day execute standard medical procedures.
At Johns Hopkins University, in Baltimore, David Gracias and his colleagues have developed these microgrippers—star-shaped devices that can be smaller than a millimeter from tip to tip. The grippers are temperature sensitive, with arms that react when exposed to body heat. If placed well, the arms will close around tissue, performing an automated biopsy.
When placed in large enough numbers, grippers like these might provide a less invasive way to screen for colon cancer. Here, a swarm of these starfish-like robots collect samples inside a pig’s gastrointestinal tract.