High efficiency wireless electrochemical actuators: Design, fabrication and characterization by electrochemical impedance spectroscopy

A wirelessly-actuated high efficiency Nafion^®-coated MEMS electrochemical actuator is presented. For the first time, high flow rates were achieved (up to 141μL/min, 13mA) under wireless operation and high efficiency pumping (up to 97%) was obtained with Nafion^®-coated electrodes; coating further prevented previously reported current-induced damage to electrodes [1]. Electrochemical impedance spectroscopy (EIS) was used for electrode characterization, electrochemical cleaning, as well as investigation of delamination, electrode polymer coating and surface activation. Parylene and PEEK were investigated as flexible substrate substitutes for soda lime glass. As a result of the combined effect of the rough PEEK surface (increased electrode surface area) and the Nafion^® coating, higher efficiency was achieved compared to glass.