Resilient and Flexible Electrohydrodynamics Pumps for Human-Machine Interfaces

Soft fluidic systems can be a versatile tool to design human-machine interfaces such as hydraulic actuators, liquid displays, and thermal haptics. Yet the bulkiness, noise, and rigidity of pumps and valves required for fluid circulation prevent their use in flexible and portable devices. This study introduces an electrohydrodynamic (EHD) driven flexible pump with resilience against dielectric breakdown. Previous EHD pumps, despite their excellent features such as quietness and high power density, suffer from dielectric breakdowns and subsequent permanent failures. This pump with novel electrode construction has the passive resilience to recover the insulation essential for EHD without any external input in the event of dielectric breakdown. The passive resilience of our pump is demonstrated in various scenarios. Notably, this pump withstands 100 dielectric breakdowns and maintains 90% of its performance. An active resilient system is also configured to enable continuous pumping. This system automatically removes bubbles and other impurities to recover flow generation. This pumps drive various soft fluid-driven human-machine interfaces like soft actuators, prosthetic hands, and tube-format displays. The combination of passive resilience inherent in the pump and active resilience configured by the system ensures adaptability and robustness, setting the stage for the next generation of human-machine interfaces.