Singapore, Mar 19: Scientists at the National University of Singapore (NUS) have engineered a self-training platform that allows lab-grown muscle tissues to exercise autonomously, producing record-breaking strength for biohybrid robots. The research team used these strengthened muscles to power OstraBot, an ostraciiform swimming robot, which reached speeds of 467 millimeters per minute — the fastest ever recorded for a skeletal muscle-driven robot. The study was published on March 18, 2026, in Nature Communications.
The breakthrough solves a long-standing bottleneck in biohybrid robotics, where weak cultured muscles have limited robot movement, force output, and functional applications. Inspired by arm-wrestling, the researchers mechanically coupled two muscle tissues so that each contraction stretches the other, creating a continuous, autonomous workout. This training requires no external stimulation, control system, or manual intervention.
“As the cells naturally contract during early maturation, connecting two tissues allows them to exercise round the clock,” said Assistant Professor Tan Yu Jun, Department of Mechanical Engineering, College of Design and Engineering at NUS, who led the study. “This approach removes a fundamental barrier in muscle-powered robotics and enables high-performance biohybrid systems designed with sustainability in mind.”
The self-trained muscles produced a maximum force of 7.05 millinewtons and a stress of 8.51 millinewtons per square millimeter, more than ten times higher than conventional muscle cultures. The NUS team then incorporated the trained muscle into OstraBot, whose design was guided by a physiology-based model of muscle activation. Using a single muscle to drive two flexible tails, the robot swam three times faster than counterparts powered by standard cultured muscle.
OstraBot also demonstrated precise controllability: its speed could be adjusted by changing electrical stimulation, and a sound-triggered system enabled it to start and stop in response to clapping signals. “The robot is not just alive — it is controllable,” noted Asst Prof Tan. “This combination of strength and regulation is critical for real-world applications of biohybrid robots.”
Looking ahead, the NUS team plans to integrate biodegradable materials into the robot’s structure, creating machines that safely degrade after completing their tasks. Potential applications include environmental monitoring in sensitive ecosystems and temporary implantable biomedical devices that eliminate the need for surgical removal.
“The ultimate goal is to create biohybrid robots that are high-performance, energy-efficient, and environmentally responsible,” Asst Prof Tan said.
