Low‐Voltage Driven Ionic Polymer‐Metal Composite Actuators: Structures, Materials, and Applications

Abstract

With the characteristics of low driving voltage, light weight, and flexibility, ionic polymer‐metal composites (IPMCs) have attracted much attention as excellent candidates for artificial muscle materials in the fields of biomedical devices, flexible robots, and microelectromechanical systems. Under small voltage excitation, ions inside the IPMC proton exchange membrane migrate directionally, leading to differences in the expansion rate of the cathode and the anode, which in turn deform. This behavior is caused by the synergistic action of a three‐layer structure consisting of an external electrode layer and an internal proton exchange membrane, but the electrode layer is more dominant in this process due to the migration and storage of ions. The exploration of modifications and alternatives for proton exchange membranes and recent advances in the fabrication and characterization of conductive materials, especially carbon‐based materials and conductive polymers, have contributed significantly to the development of IPMCs. This paper reviews the progress in the application of proton exchange membranes and electrode materials for IPMCs, discusses various processes currently applied to IPMCs preparation, and introduces various promising applications of cutting‐edge IPMCs with high performance to provide new ideas and approaches for the research of new generation of low‐voltage ionic soft actuators.

Soft Fiber/Textile Actuators: From Design Strategies to Diverse Applications

“…This research provides valuable insights into fabricating lightweight, low-voltage driven, and simple-structured actuators. For an in-depth review of the design of IPMC actuator structures, materials, and applications, the article by Zhang and colleagues is recommended …”

“…For an indepth review of the design of IPMC actuator structures, materials, and applications, the article by Zhang and colleagues is recommended. 153 Fiber actuators can also be actuated by electromagnetic Lorentz forces (nonmagneto thermal effect). For instance, a fiber/coil-shaped actuator actuated by electromagnetic forces was proposed.…”

“…Ionic-polymer–metal composite (IPMC) is a sandwich structure composed of electrodes, ion exchange membranes, and electrodes . IPMC is ideal for artificial muscles because of its light weight, ease of manufacture, low cost, and ability to migrate ions at low voltages (generally below 10 V). , Unlike electrochemical actuators, IPMC operates without the need for liquid electrolytes. Ma et al developed a Nafion-based IPMC actuator via isopropyl alcohol chemical plating .…”

Bioinspired Anisotropic Microstructures toward Multimodal Deformations of Low‐Voltage‐Driven Ionic Actuators

“…Electroactive polymers soft actuators are an important branch of artificial muscle, among which IPMCs are a class of low-voltage driven ionic actuators that have drawn much attention in the field DOI: 10.1002/admt.202300369 of soft robotics and biomedical devices over the decades. [1][2][3][4][5] IPMCs are composed of an ionic exchange polymer membrane and two metal electrodes symmetrically distributed on both sides of the membrane. The hydrated IPMCs can deform after a voltage is applied across the electrodes.…”

Carbon‐Based Nanomaterials Electrodes of Ionic Soft Actuators: From Initial 1D Structure to 3D Composite Structure for Flexible Intelligent Devices

“…The typical structure of the IPMC actuator is a three-layer structure with an intermediate ionic polymer membrane and asymmetrical metal electrodes on both sides. [25,26] The manufacturing process usually includes three parts: 1) polymer surface treatment (roughening); 2) adsorption of metal ions into ion exchange membranes in polymers; 3) deposition of metal electrodes on both sides of the ionic polymer film. [27] For one thing, ionic polymer membranes include cation exchange membranes and anion exchange membranes, and their conductivity, ion exchange capacity, and flexibility are some important factors affecting the IPMC driving performance.…”