Researchers at MIT have developed artificial tendons made from tough, flexible hydrogel, a move that significantly improves the performance of biohybrid robots that use lab-grown muscle as actuators, says Tech Xplore. By attaching these hydrogel tendons to both ends of a small muscle sample and connecting them to a robotic gripper skeleton, the team created a “muscle–tendon unit.” When the muscle contracts, the tendons transmit force to the gripper, enabling much stronger, faster motion than the muscle alone.
Tests showed that with artificial tendons, the gripper closed its fingers three times faster and generated 30 times more force compared with a similar design lacking tendons. The enhanced design also sustained performance over 7,000 cycles and achieved an 11-fold boost in power-to-weight ratio, meaning robots can do more work with less muscle tissue.
This tendon-based design addresses a core challenge in biohybrid robotics: the mismatch between soft biological muscle and rigid synthetic skeletons. Without tendons, muscle often tears or fails to transmit enough force; the hydrogel connectors bridge this stiffness gap, making force transmission reliable and repeatable.
The researchers believe this modular muscle–tendon unit could be used across a wide range of biohybrid robots—from micrometer-scale surgical tools to autonomous machines operating in hostile environments. This advance brings such robots closer to real-world use by improving power, durability, and adaptability.