Electrofluidic Fiber Muscles (Science Robotics)

Electrohydrodynamic (EHD) Fiber Pumps

Charge-injection EHD fiber pumps are mm-scale soft tubes with embedded helical electrodes that silently generate pressure and flow without moving parts, solving the longstanding problem of integrating pressure generation in portable systems.

To learn more about electrohydrodynamic fiber pumps (Science, 2023): science.org/doi/10.1126/science.ade8654

We use a custom multi-filament winding apparatus to manufacture pumps with various monofilament materials and geometries. The tool can be customized to change the pump diameter, inter-electrode gap as well as the distance between each electrode pair, all of which affect the pump's performance.

Fiber pumps directly convert electrical energy into fluid pressure and flow. Measuring less than 2 mm in diameter, these slender, power-dense pumps generate up to 900 kPa/m and can be used for compact thermal management or as embedded fluidic power sources for soft robotic systems.

Integrating fiber pumps with antagonistic fiber actuators: electrically driven muscle with power density comparable to skeletal muscle

Muscle-driven lever arm rapidly launching objects

A lever arm setup was connected to an antagonistic pair of McKibben actuators and four fiber pumps arranged fluidically in parallel configuration to increase flow rate and hence shorten response time to < 200 ms.

Woven biceps-triceps muscle pair

A key advantage of 1-mm fiber muscles is that we can intertwine them into textiles. To demonstrate this capability, we fabricated flat textile muscle pairs by weaving McKibben actuators and fiber pumps together. 

Modular scalability allows architected muscles for robotics, including compliant and back-stretchable woven muscle pairs driving robotic arms.