Evaluation and Comparison of Reversible Water Electrolysis as a Means for Pneumatic Actuation

Abstract

This work presents an evaluation of reversible water electrolysis as a method for pneumatic actuation via the electrochemical decomposition of water into hydrogen and oxygen gas. In addition to a theoretical evaluation of the performance of electrochemically-driven pressurized hydrogen generation, pneumatic generation methods were experimentally tested across two axes: performance and compatibility. Through these experiments, the achievable pressure was shown to be at least 0.75 MPa gauge with a flow rate of 0.06 [L/min]. It was also determined that negligible losses were incurred due to switching from air to hydrogen. Despite low experimental round-trip efficiencies of 0.005%, the reversible electrolysis of water reaction was shown to be a feasible method for pneumatic actuation of soft robots, especially under scenarios where actuator bandwidth is not of concern.