MIT engineers have demonstrated a paper-thin swimming robot propelled entirely by living muscle. Developed in Associate Professor Ritu Raman's laboratory in the Department of Mechanical Engineering, with graduate researcher Maheera Bawa as first author, the robot was reported in Advanced Functional Materials. Its skeleton is a flexible gel film about the size of a stick of gum, split into two fins, each coated with a layer of genetically engineered muscle cells thinner than a hair that twitch when exposed to light.
Flashing light on one fin or the other steers the device, and in trials the robot navigated a watery maze, covering roughly four body lengths per minute at its fastest: slow by human standards but comparable, the team notes, to a cow shark. To coax more force from the biological tissue, the researchers tuned the gel's composition, stiffness and surface grooves, and conditioned the muscles with repeated light stimulation, in effect exercising them.
The result points towards a class of flat, two-dimensional biohybrid machines that could prove cheaper and more efficient than designs built around bulky lab-grown muscle blocks. Supported in part by the Office of Naval Research, the work opens a path to small, soft swimmers suited to delicate tasks such as environmental monitoring, with the team now optimising the body plan for greater speed.