MIT Engineers Build a Paper-Thin Swimming Robot Powered by Living Muscle Cells
October 23, 2026 — Massachusetts Institute of Technology
Summary
MIT engineers have built a paper-thin swimming robot powered by living muscle cells that contract in response to flashes of light, allowing it to swim and steer through water. The breakthrough could pave the way for tiny, self-healing biological robots capable of exploring fragile environments that conventional machines cannot safely navigate.
A New Approach to Underwater Propulsion
A swimming robot does not necessarily need a bulky motor or powerful mechanical parts to move through water. MIT researchers have demonstrated that a single, carefully engineered layer of living muscle cells can generate enough force to propel a tiny robot forward.
The engineers developed an extremely thin swimming robot that uses living muscle tissue to move its fins. Described in a new study published in Advanced Functional Materials, the device features a flexible gel framework roughly the length and width of a stick of gum. The gel forms two fins, each coated with a layer of muscle cells far thinner than a human hair. These cells have been genetically modified to contract when exposed to light.
By directing light onto either fin, the researchers can trigger muscle contractions that make the fin flap and push the robot through water. Adjusting which fin receives light and how frequently it is illuminated allows the team to control both the robot's speed and direction.
Performance in Testing
In experiments, the remarkably thin robot successfully swam and turned through a simple underwater maze. At maximum speed, it covered approximately four times its body length per minute. Although that is far slower than an Olympic swimmer—who can travel up to 65 body lengths per minute—it is comparable to the leisurely swimming pace of a cow shark moving through the ocean.
"It takes a lot of force to move through water versus air," says study author Ritu Raman, associate professor of mechanical engineering at MIT. "The robot's quite strong, given its size."
A New Generation of Robots Powered by Living Muscle
The device represents the first demonstration of a very thin, two-dimensional robot that can move from place to place using living muscle tissue.
Most existing biohybrid robots rely on relatively large, three-dimensional structures made from laboratory-grown skeletal muscle. By contrast, this approach uses a single layer of engineered cells, enabling an exceptionally thin and lightweight design that could open new possibilities for microscale robotics.
As of 2026, the field of biohybrid and soft robotics has accelerated rapidly, with researchers increasingly integrating living tissues—muscle, neurons, and other cell types—into synthetic scaffolds to achieve locomotion and sensing capabilities that purely mechanical systems struggle to replicate. Optogenetic control, in which cells are genetically modified to respond to light, has become a preferred method for precisely steering these living machines without tethers or bulky onboard electronics. MIT's latest device advances this trend by demonstrating that even a two-dimensional, paper-thin architecture can generate meaningful propulsion, a finding that may inform future work on self-healing, biodegradable robots designed for environmental monitoring, drug delivery, and exploration of delicate aquatic ecosystems.
Source: Massachusetts Institute of Technology
Image credit: Melanie Gonick, MIT