https://phys.org/news/2018-12-hydraulic-actuator-robots-tougher.html

Tokyo Tech School of Engineering professor Koichi Suzumori and colleagues developed a hydraulic actuator to solve these issues. The actuator offers greatly increased power and shock resistance compared with conventional electric motors. It also grants a smaller size, higher output (force-to-mass ratio), and smoother control compared with conventional hydraulic actuators. Providing high power, durability, and excellent control, the actuator will allow robots to operate in the harshest of environments and perform tough work with a gentle touch.

This hydraulic actuator is the result of the Tough Robotics Challenge, organized by the Impulsing Paradigm Change through Disruptive Technologies Program (ImPACT) of the Cabinet Office of Japan. Tokyo Tech; JPN Co., Ltd.; Bridgestone Corporation; and KYB Corporation; along with other universities and enterprises concerned with hydraulic equipment, have participated in development of the hydraulic actuator for tough robots since 2014. To promote adoption of the technology, H-MUSCLE will ship samples of its hydraulic cylinders and hydraulic motors to domestic manufacturers, expand its lineup of actuators for future sale, and explore further applications.