New tendon tech makes living muscle robots faster and far stronger

MIT engineers have developed a groundbreaking biohybrid robotic system that integrates lab-grown muscles with artificial tendons made from tough, flexible hydrogels. These hydrogel tendons act as rubber band–like connectors between muscle actuators and robotic skeletons, significantly enhancing the speed, strength, and durability of muscle-powered robots. The tendon-enhanced robotic gripper demonstrated a threefold increase in speed and a 30-fold increase in force compared to muscle-only systems, while also achieving an 11-fold improvement in power-to-weight ratio. This modular design allows for more efficient force transmission and reduces muscle requirements, addressing previous challenges of tearing and detachment in biohybrid robots. Led by MIT’s Ritu Raman, the team engineered the tendons by modeling the system as three springs—muscle, tendon, and skeleton—to optimize stiffness and flexibility. The hydrogel tendons, developed in collaboration with co-author Xuanhe Zhao, adhere well to both biological and synthetic materials, enabling robust and repeatable