Researchers developed soft actuators for building entirely soft robots for a wide range of soft robotic applications.
Soft robots can interact with some delicate objects in ways that traditional rigid robots can’t. These soft robots are mostly driven by pressurized fluids. However, building entirely soft robots is a challenge because many of the components required to power these devices are, themselves, rigid. These rigid regulation systems significantly limit the adaptability and mobility of the soft robots.
Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed electrically-driven soft valves to control hydraulic soft actuators. This opens up new possibilities for soft on-board controls for future fluidic soft robots. The soft valves can be used in a wide range of applications such as in assistive and therapeutic devices, bio-inspired soft robots, soft grippers, surgical robots, and more.
Soft valves aren’t new but the pressure or flow rates required by many existing hydraulic actuators have not been achieved yet. To solve these issues, the researchers developed new electrically powered dynamic dielectric elastomer actuators (DEAs) that have ultra-high power density, are lightweight, and can run for hundreds of thousands of cycles. The team combined this actuator with a soft channel, resulting in a soft valve for fluidic control.
“These soft valves have a fast response time and are able to control fluidic pressure and flow rates that match the needs of hydraulic actuators,” said Siyi Xu, a graduate student at SEAS and first author of the paper. “These valves give us fast, powerful control of macro-and small-scale hydraulic actuators with internal volume ranging from hundreds of microliters to tens of milliliters.”
“This compact and light-weight DEA valve is capable of unprecedented electrical control of hydraulic actuators, showing the potential for future on-board motion control of soft fluid-driven robots,” said Xu.
The research appeared in the Proceedings of the National Academy of Sciences.