A Soft Electrochemical Actuator for Biomedical Robotics

Abstract

This paper presents a new biphasic electrofluidic rotary actuator relying on electrochemical mechanisms. Gas (H <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> and O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> ) is generated at two platinum (Pt) electrodes, immersed in an electrolytic solution, when a low voltage, V, is applied to them. The generated gas pressurizes a closed elastomeric chamber, that deforms under the action of the applied pressure. The chamber is shaped so that no structural failure occurs and the desired output motion is produced, without any need for additional mechanical means such as motion converters. Simple thermodynamic considerations allow estimating the electromechanical coupling factors for the most common external loads.