Nanostructural Aspects of Conducting‐Polymer Actuators

Abstract

Dimensional changes in conducting polymers such as polypyrrole (PPy), polyaniline (PANI), and poly(3,4-ethylenedioxythiophene) (PEDOT) during oxidation and reduction have been used for over 15 years to create movement, an actuating effect. This has opened up the possibility of the development of a new class of polymer-based, large strain, artificial muscles, to stand alongside other prospective materials, such as dielectric elastomers, shape-memory alloys, and carbon nanotube fibers [1]. Advantages of conducting polymers over more established actuator technologies, such as piezoelectric polymers, are seen in their low operation voltages, high work densities per cycle, and force generation capabilities, but with limitations seen in cycle life and energy conversion efficiencies [2].However, a complete picture of the volume changes at work in conducting polymers has yet to be determined [3], and it is widely recognized that an understanding and better exploitation of nanostructural aspects of conducting-polymer actuators will be necessary to improve their performance as required for practical applications [4][5][6][7]. In this chapter we will outline the main mechanisms of actuation which have been investigated for conducting-polymer actuators, along with recent research to model actuator performance and develop applications. The effect of morphology and nanostructure, such as chain Nanostructured Conductive PolymersEdited by Ali Eftekhari

Electrical and Electrochemical Properties of Conducting Polymers

“…This phenomenon has been proposed to be exploitable for a new generation of actuators. CP actuation can be chemically and electrochemically controlled [ 102 ]. Representatively, the mechanism of the electrochemical actuation in CPs is illustrated in Figure 9 .…”

“…In addition to tailoring the properties of the main components, such the CP and electrolytes, it is very important to design efficient actuating systems for significant improvement of the performance of CP-based soft actuators. Several remarkable actuating systems have been designed, such as bilayer-trilayer actuators, out-of-plane actuators, and linear actuators [ 102 ].…”

Comment on “A Linear Actuation of Polymeric Nanofibrous Bundle for Artificial Muscles”

“…Sir: Gu et al have fabricated an electrochemical actuator based on a polymeric nanofibrous bundle for use as artificial muscle. It is well known that the actuation of intrinsically conducting polymers is due to the movement of ions and solvent in and out of the polymer during oxidation and reduction processes . Thus, as a part of electrochemical studies, the cyclic voltammetric behavior has been interpreted by the classic Randles−Sevcik equation.…”

A Lightweight and Low-Voltage-Operating Linear Actuator Based on the Electroactive Polymer Polypyrrole

“…This can be attributed to the electrochemical redox reaction mechanism that drives the PPy actuators. When the PPy backbone undergoes electrochemical oxidation, it becomes positively charged, and the anion from the electrolyte is incorporated into the film as a dopant, leading to elongation of the PPy main chain [ 37 , 38 , 39 , 40 , 41 , 42 ]. Accordingly, it is revealed that the polymerization conditions, especially the choice of electrolyte and solvent, have a significant impact on actuator performance.…”