Electrochemomechanical Devices: Artificial Muscles

Abstract

Science is one of the most robust conceptual constructs developed by human beings. Theoretical physical models have been developed involving the smallest and the largest systems over the full scale of the universe. At either extreme, the models, which provide for constant interaction forces between their components, describe experimental observations and are predictive.Life evolved from systems of intermediate size in relation to the extremes of universal scale. Life, biological organs, and cells develop functions only under chemical driving conditions. Natural organs can be considered as biological devices that are very efficient in transforming chemical energy at constant temperature into functions, unlike servitude of machines to the Carnot cycle. Inside any living cell, thousands of simultaneous reactions occur. Every reaction promotes changes from reactants to products, with subsequent changes to hundreds of intramolecular and intermolecular interactions. Moreover, most of those reactions link conformational changes of biopolymers with ionic and electronic movement driving water flow. Hence, many simultaneous chemical reactions, intermolecular, and intramolecular interactions involving conformational movements are outside the possibilities of current theoretical models. Theoretical descriptions of any living cell and predictions of its behavior when unhealthy are unavailable within our scientific models. This constitutes the proximity paradox [1] because we have been able to develop good and predictive theoretical models for subatomic or galactic systems, far removed from our everyday surroundings.Actuation of natural organs such as muscles involves, moreover, the chemical reaction of ATP hydrolysis simultaneous with sensing processes that provide living creatures with a perfect consciousness of both the characteristics of their mechanical movements and their interactions with their environment: they are intelligent machines.Most of our technological developments were inspired by biological functions and organs. One of our aims is to overcome the efficiency of the biological Electropolymerization: Concepts, Materials and Applications. Edited by Serge Cosnier and Arkady Karyakin

A liquid-junction-free reference electrode based on a PEDOT solid-contact and ionogel capping membrane

“…Regarding the effect of the CP redox state, it is significant to note that previous reports have highlighted the crucial role of charging/discharging processes of the conducting polymer at the potentiometric detection limit of SC-ISEs [27]. Less obviously, the media used for the CP electro-polymerization may impact on the doping/de-doping of the CP since this process depends on the anions incorporated in the polymer skeleton backbone [29,30] Figure S4. Figure S5 shows that typically the current and the total charge passed in the oxidative region, and therefore the amount of weeks after its electrodeposition prior depositing the capping membrane.…”

Artificial muscles driven by the cooperative actuation of electrochemical molecular machines. Persistent discrepancies and challenges

“…Thus, electro-chemo-mechanical actuators or artificial muscles are Faradaic devices: the volume variation (required to lodge/expel exchanged ions and solvent molecules) and the concomitant strain is expected to be a linear function (through Equation (2)) of the charge, Q, consumed by the reaction. The movement rate to go every time from the same initial position to a final position (always the same) must be a function of the ions and solvent exchange rate, controlled (Equation (2)) by the flowing current (I) [103][104][105][106][107]. Therefore the influence of different experimental conditions (temperature, ionic concentration, concentration of active centers, pressure or mechanical conditions) on the muscular actuation will be described by the electrochemical kinetics, i.e.…”

Properties and Customization of Sensor Materials for Biomedical Applications

“…They have received ever-increasing attention since the seminal contribution of Heeger, MacDiarmid, and Shirakawa, who jointly received the Nobel prize for chemistry in 2000 (129)(130)(131)(132). While they were initially investigated as substitutes for metals, their range of applications quickly expanded covering several research fields such as electrocatalysis, energy storage, and sensing (133).…”