PEDOT-Based Conducting Polymer Actuators

Abstract

Conducting polymers, particularly poly(3,4-ethylenedioxythiophene) (PEDOT) and its complex with poly(styrene sulfonate) (PEDOT:PSS), provide a promising materials platform to develop soft actuators or artificial muscles. To date, PEDOT-based actuators are available in the field of bionics, biomedicine, smart textiles, microactuators, and other functional applications. Compared to other conducting polymers, PEDOT provides higher conductivity and chemical stability, lower density and operating voltages, and the dispersion of PEDOT with PSS further enriches performances in solubility, hydrophility, processability, and flexibility, making them advantageous in actuator-based applications. However, the actuators fabricated by PEDOT-based materials are still in their infancy, with many unknowns and challenges that require more comprehensive understanding for their current and future development. This review is aimed at providing a comprehensive understanding of the actuation mechanisms, performance evaluation criteria, processing technologies and configurations, and the most recent progress of materials development and applications. Lastly, we also elaborate on future opportunities for improving and exploiting PEDOT-based actuators.

Template-Assisted Self-Assembly of Conductive Polymer Electrodes for Ionic Electroactive Polymers

“…As noted previously, CP electrodes also have the problem of delamination when attached to a SPE (Bhandari et al, 2012;Lee et al, 2013;Kotal et al, 2016;Rasouli et al, 2017;Hu et al, 2019). This can be highly problematic under minimally invasive surgeries where the actuators would be introduced to wet conditions since these conditions would reduce the adhesion between CP electrodes and the SPE (Inoue et al, 2020).…”

“…This is possible because EAP-based actuators have one continuous body which means that there are less parts needed to be assembled, and it also simplifies the programming of its movements (Alici, 2018). Ionic polymer metal composite (IPMC) actuators are EAPs that have been studied extensively in literature, but these devices require its electrodes to be made with either gold or platinum and therefore are too expensive to mass produce (Bhandari et al, 2012;Lee et al, 2013;Kotal et al, 2016;Rasouli et al, 2017;Hu et al, 2019). Alternatively, conductive polymer (CP) actuators can be used instead.…”

“…Alternatively, conductive polymer (CP) actuators can be used instead. Since these actuators are not constrained to metallic electrodes, they are more affordable, and can produce higher actuation strains (Hu et al, 2019).…”

“…Nafion-based solid polymer electrolyte (SPE) with electrodes have been extensively used since Nafion is widely available and is biocompatible (Lee et al, 2013;Kotal et al, 2016;Rasouli et al, 2017). However, many studies have reported that combining Nafion with CP electrodes will result in poor actuations at low voltages (Lee et al, 2013;Vreeland et al, 2015;Rasouli et al, 2017;Hu et al, 2019). One study coated the Nafion surface with carbon nanotubes (CNTs) and carbon black (CB) ink before polymerizing the membrane with CP electrodes, but found this method showed unnoticeable tip displacements below 2.0 V (Rasouli et al, 2017).…”

A facile template-free strategy for synthesizing hydroxymethyl-poly(3,4-ethylenedioxythiophene) nanospheres

“…To further create different micro-and nanostructures, some studies on controlled polymerization of conducting polymers have been furtherly performed. The controlled morphologies of conducting polymers have been developed by soft templates such as DNA scaffolds 6 , amphiphilic peptides 7 , small molecules 8 , biomembrances 9 , and cellulose derivatives 10 as well as hard templates such as anodic aluminum oxide 11 , mesoporous silica 12 , hydrogel bio electronics [13][14][15] and actuator 16 . On the other hand, there are a few reports on one-step synthetic strategies to produce PEDOT 3D nanostructures.…”