Progress and prospective of electrochemical actuator materials

Similar to biological muscles, electrochemical actuators can function as artificial muscles by directly converting an external stimulus in the form of electrical or chemical energy into a mechanical response via reversible changes in material dimensions. Compared with traditional actuators, electrochemical actuators exhibit typical advantages of a low drive voltage, nanoscale accuracy, and lightweightness, which render it with long service life. In particular, electrochemical actuator materials can operate in liquid environments and have been widely studied in several important fields, such as flexible robots, micro-pumps, and micro-actuators. In this review we focus on the recent developments and applications of electrochemical actuator materials. First, the principles of electrochemical actuation are introduced; subsequently, the materials of electrochemical actuators are summarized based on their research status. The advantages and disadvantages of various actuator materials are discussed and some problems of electrochemical actuators in practical use are highlighted for the prospect of their development.