An ionic electro-active actuator made with graphene film electrode, chitosan and ionic liquid

Abstract

A newly developed ionic electro-active actuator composed of an ionic electrolyte layer sandwiched between two graphene film layers was investigated. Scanning electronic microscopy observation and x-ray diffraction analysis showed that the graphene sheets in the film stacked in a nearly face-to-face fashion but did not restack back to graphite, and the resulting graphene film with low sheet resistance (10 Ω sq −1 ) adheres well to the electrolyte membrane. Contact angle measurement showed the surface energy (37.98 mJ m −2 ) of the ionic electrolyte polymer is 2.67 times higher than that (14.2 mJ m −2 ) of the Nafion membrane, contributing to the good adhesion between the graphene film electrode and the electrolyte membrane. An electric double-layer is formed at the interface between the graphene film electrode and the ionic electrolyte membrane under the input potential, resulting in a higher capacitance of 27.6 mF cm −2 . We report that this ionic actuator exhibits adequate bending strain, ranging from 0.032 to 0.1% (305 to 945 μm) as functions of voltage.

Review on Improvement, Modeling, and Application of Ionic Polymer Metal Composite Artificial Muscle

“…4. These cracks on the electrode cause water molecules to leak out of the electrodes, which affects the IPMC hydration degree, causes energy loss, significantly reduces the conductivity of the electrode, and degrades the IPMC actuation performance [84]. Moreover, platinum nanoparticles are unstable and become active catalysts, which is attributed to the change in atomic configuration and electron spin caused by the activity of atoms on the nanosurface [85].…”

Improvement in electromechanical performance of degradable bio‐inspired soft ionic actuators with high energy density conductive electrodes

“…where C is the specific capacitance of ion actuators (mF g −1 ), I is the current density (A g −1 ), Δt is the charge and discharge time, m is the mass of active substances on the electrode, and ΔV is the voltage drop during discharge. Figure 5A-E shows the GCD curves of different types of electrode membranes at different current densities (1,2,5,8, and 10 Ag −1 ). The charge-discharge curve exhibits relatively weak symmetry and exhibits an imperfect linear shape, indicating some irreversible changes in the charge and discharge process of the electrode.…”

“…Since the conductive polymer (CP) material has both a polymer structure and electrical conductivity, it has many properties unmatched by other materials. In the following 40 years, CP materials with similar properties, such as polypyrrole (PPY), polyaniline (PANI), polythiophene (PTH) and its derivatives (PEDOT) have been discovered. Among them, PPY and PANI are both N‐type conjugated CPs, and PEDOT is an S‐type conjugated CP.…”

Active Tube-Shaped Actuator with Embedded Square Rod-Shaped Ionic Polymer-Metal Composites for Robotic-Assisted Manipulation

“…When an electric field is applied, the actuation mode of a strip IPMC generates 1-dimensional bending toward the anode. An extensive study has been conducted in improving the performance of IPMCs [ 14 ], including the development of novel ionic polymer membranes through a polymer blending method and nanocomposite membranes [ 15 – 23 ], the replacement of traditional metallic electrodes by nonmetal electrodes such as carbon nanotube-based electrodes [ 24 , 25 ], and the optimization of the electrode interface [ 26 ], increasing the thickness of Nafion membranes through a solution casting method and a hot pressing technique [ 27 , 28 ]. Although the performance of IPMCs has been improved, the 1-dimensional bending motion of traditional strip-type IPMCs limits its applications.…”