Stretchable Dielectric Fluid Pumps for Soft Fluid Power Systems

Soft fluid power systems offer advantages of flexible output designs, ease of control, and simple structures, which enable them to facilitate a wide range of intriguing applications in soft and interactive human-machine interfaces. Fluid pumps play a pivotal role in fluid power systems. However, the performance of soft fluid pumps developed for fluid power systems remains limited, requiring further research to improve their mechanical compliance and output capabilities. Here, a stretchable dielectric fluid pump (DFP) is presented that can provide silent and flexible controls of pressurized fluids to power hydraulic circuits. The device can provide pressures up to 8 kPa and instantaneous flow rates up to 304 mL min⁻¹ with a minimum thickness of 2.2 mm. An equivalent circuit model is proposed to provide new insights into the working mechanism of stretchable pumps driven by electrostatic actuation. As a peristaltic pump, it is capable to drive loads consistently in the hydraulic circuit and can be easily augmented through design of the hydraulic circuit to lift substantial loads. With its advantages of quiet operation, lightweight design, and large compliance, the DFP is expected to advance next-generation soft fluid power technologies for soft robots, wearable machines, and electro-fluidic hybrid systems.