Wireless Dual Stimuli Actuation of Dye Sensitized Conducting Polymer Hybrids

Abstract

Actuators controlled by external stimuli have received a lot of attention in recent years. Herein a polymer based dual stimuli actuator is reported, triggered by light and an electric field. This allows better control of actuation, enlarging the field of potential applications, like, for example, in the frame of soft robotics. The actuator is composed of polypyrrole and TiO 2 modified with methylene blue. In an aqueous solution, the resulting freestanding hybrid film shows reversible actuation due to the synergy of light and an applied electric field. Illumination with light produces electron-hole pairs in the TiO 2 layer, which are shuttled to the opposite ends of the actuator by the potential gradient present in the solution. This results in electrochemical oxidation and reduction reactions at the two extremities and consequently in site selective swelling of the polymer, which finally leads to a controlled motion of the actuator, following the principles of logic gate operations. Such synergistically induced switching allows developing original actuation schemes for performing complex mechanical tasks triggered by more than one stimulus.

Recent Advances in Bipolar Electrochemistry with Conducting Polymers

“…In a recent approach, actuators that respond to a double stimulus such as an electric field and light were proposed. A hybrid Ppy‐TiO 2 film, modified with methylene blue as a sensitizer, was used as BPE for the design of a wireless on/off switch [60] . Under illumination electron‐hole pairs are produced in the TiO 2 layer, which, in the presence of a potential gradient, move towards the Ppy extremities.…”

Cover Feature: Recent Advances in Bipolar Electrochemistry with Conducting Polymers (ChemElectroChem 1/2022)

“…A hybrid Ppy-TiO2 film, modified with methylene blue as a sensitizer, was used as BPE for the design of a wireless on/off switch. [60] Under illumination electron-hole pairs are produced in the TiO2 layer, which, in the presence of a potential gradient, move towards the Ppy extremities. This triggers the oxidation and reduction at both sides of the BPE, leading to the deformation of the polymer.…”

Photothermal modulated dielectric elastomer actuator for resilient soft robots

“…Co-stimulation of actuators has been explored at which two stimuli are applied concurrently to achieve a particular function 18 , 19 . Such co-activation is analogous to athletes warming up their muscles before an exercise.…”