Artificial muscle like behavior of polypyrrole polyethylene oxide independent of applied potential ranges

Abstract

The development of artificial muscles replicating natural muscles is envisaged for the construction of soft devices and robots working at low voltages. Here we present the parallel electrosynthesis, characterization, and isometric and isotonic study of Electro-Chemo-Mechanical-Deformations from polypyrrole doped with dodecylbenzenesulfonate (DBS À ) with addition of 10 wt.% polyethylene oxide (PEO) forming PPy-PEO/DBS films and PPy/DBS films. They were submitted to potential cycling or consecutive potential steps (0.0025 Hz-0.1 Hz) using different potential ranges (0.8 to À0.4 V, 0.65 to À0.6 V and ±1.0 V) in a solution of bis(trifluoromethane) sulfonimide lithium in propylene carbonate (LiTFSI-PC). The PPy-PEO/DBS linear films showed anion-driven actuation while PPy/DBS revealed mixed ion (cation and anion) actuation. The PPy-PEO/DBS film samples present the higher strain range of 20% (stress over 1 MPa) with 2 times higher strain and stress variations than the PPy/DBS films. The potential range 0.8 to À0.4 V showed best results for PPy-PEO/DBS in long-term cycling stability up to 1000 cycles of 4.2% strain and 0.35 MPa stress, suitable for artificial muscle like applications. Material characterization considered before and after actuation cycles was made with scanning electron microscopy, energy-dispersive X-ray, and Raman spectroscopy.

Effects of Side-Chain Length and Functionality on Polar Poly(dioxythiophene)s for Saline-Based Organic Electrochemical Transistors

“…The electrochemical functionality of π-conjugated polymers has been leveraged to develop devices with a broad range of applications, including optical displays, , energy storage devices, , neuromorphic computing elements, , and bioelectronic interfaces. , In recent years, the field of organic bioelectronics has undergone significant advancements, as it has become increasingly apparent that π-conjugated polymers offer highly desirable properties for interfacing with living systems’ mechanical conformability, low-voltage operation, facile chemical modification, and compatibility with biological media. This has led to a renewed interest in developing active materials for bioelectrochemical devices, such as organic electronic ion pumps, neural probes, , artificial muscles, , and organic electrochemical transistors (OECTs) . In particular, OECTs have garnered significant attention due to their ability to transduce cellular ion fluxes (e.g., protons, metal cations, and neurotransmitters) into exogenous electrical signals with extremely high signal fidelity. , …”

Linear sensing actuators of polypyrrole nanofiber scaffolds

“…The PPyDBS and PPyDBS‐CNS samples are compared given linear actuation properties (strain). Different PRs are applied because of previous works 32 describing mixed actuation (anion‐driven and cation‐driven) using PPyDBS and large PRs. Here, the electropolymerization was driven at −40°C in order to get dense and packed films 33 .…”

“…The samples were submitted to different electrochemical methodologies: cyclic voltammetry (scan rate 5 mV s −1 ), consecutive square potential waves at different frequencies (0.0025–0.1 Hz) with combined strain measurements. Going on recent research, 32 here, we will investigate the influence of different applied PRs named PR1 (1.0 to −0.55 V), PR2 (0.8 to −0.4 V), and PR3 (0.65 V to −0.6 V). For PR2, chronopotentiometric (square wave current) measurements were conducted using constant currents (from ±0.05 to ±2 mA).…”

Role of Polyoxometalate Contents in Polypyrrole: Linear Actuation and Energy Storage

“…Here, we show the effect of PPy/DBS-PT films in an organic electrolyte while keeping in mind that pristine PPy/DBS changed the actuation direction from cation-driven in the aqueous electrolyte to anion-driven in an organic electrolyte [ 18 , 24 ]. Besides the applied solvent in electropolymerization [ 20 ], the potential window also plays a role in the actuation direction [ 25 ]. Here, we have chosen the potential window of 1.0 to −0.55 V, which shows, in most cases of pristine PPy/DBS films, the main expansion upon oxidation, while small expansion upon reduction was also observed depending on the applied electrolytes [ 26 ].…”