Different Approaches to Increasing the Continuous Operation Time of IPMC Actuators

IPMC actuators have great potential in robotics due to low control voltages and high output displacements. A major limitation is the use of aqueous electrolytes, which reduces the time of their continuous operation in air due to water evaporation and electrolysis. To increase it, two approaches have been investigated: encapsulation and the use of non-aqueous electrolytes. It was experimentally found that the continuous operation time of the water-impregnated IPMC actuator after encapsulation with a 15 μm-thick parylene layer increased by 10 times at a control signal of 4 V 1 Hz. However, this approach does not solve the problem of water electrolysis in DC mode. The use of nonvolatile ionic liquids with a wide electrochemical stability window made it possible to solve this problem. By replacing water with EMIM-BF
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ionic liquid, the continuous operation time of IPMC actuators increased to more than 24 h.