a Polypyrrole-dodecylbenzenesulphonate-multi-walled carbon nanotube (PPy-DBS-MWCNT) films, thick enough (48.6 µm) to be peeled off from the steel electrode, were electrogenerated. Bilayer PPy-DBS-MWCNT/tape artificial muscles were constructed and submitted to potential sweeps with parallel video-recording of their angular displacements. The coulodynamic (angle-charge) responses reveal that the composite shrinks/swells by oxidation/reduction, respectively, due to the reaction-driven cation exchange. Reversible bending movements of 106° occur under faradaic (linear) control of the consumed charge. Minor deviations and hysteresis were identified with irreversible reactions and osmotic processes. The muscle is a faradaic motor.

Thick films of polypyrrole/polyvinylsulfate (PPy/PVS) blends were electrogenerated on stainless‐steel electrodes under potentiostatic conditions from aqueous solution. The best electropolymerization potential window was determined by cyclic voltammetry. After removing the film from the back metal, self‐supported electrodes were obtained. Voltammetric, coulovoltammetric, and chronoamperometric responses from a LiClO4 aqueous solution indicated the formation of an energetically stable structure beyond a reduction threshold of the material. Its subsequent oxidation required higher anodic voltammetric overpotentials or longer chronoamperometric oxidation times. This structure was attributed to the formation of lamellar or vacuolar structures. X‐ray photoelectron spectroscopy analysis of the films under different oxidations states revealed that the electrochemical reactions drive the reversible exchange of cations between the film and the electrolyte. The electrical energy and the charge consumed by the reversible reaction of the film under voltammetric conditions between the constant potential limits are a function of the potential scan rate, that is, they sense the working electrochemical conditions.

In the dense gel that is the intracellular matrix forming part of living cells electrochemical reactions take place provoking the interchange of ions and water with the surroundings. Systems containing conducting polymers mimic this feature of biological organs. In particular, conducting polymers are being studied as dual sensing-actuating reactive materials giving new multifunctional sensing-actuators, which allow the construction and theoretical description of artificial proprioceptive devices. Here films of polypyrrole/dodecyl benzene sulfonate (PPy-DBS) coating a platinum electrode were submitted to potential sweeps at different sweep rates in order to explore if the polymer reaction senses the working electrochemical conditions. The effective consumed electrical energy per cycle follows a fast decrease when the scan rate increases described by the addition of two exponential sensing functions. Moreover, the variation of the hysteresis from the parallel charge/potential loop with the scan rate is also described by the addition of two exponential functions. In both cases the exponential functions fitting results at low scan rates are related to reaction-driven conformational movements of the polymer chains, being closer to biochemical conformational and allosteric sensors. The second exponential functions fitting results at high scan rates are related to diffusion kinetic control, being closer to present electrochemical sensors.

How would you describe to the layperson the most significant result of this study?An ew technological world of electrochemical sensorimotors mimicking biological muscles is emerging, requiring thick films of conducting polymers for theirc onstruction.H ere, we present how the best conditions to generate thick films of the polypyrrole/polyvynivlsuphonateb lend are determined, how the self-supportede lectrodes are constructed,a nd how their electrochemical and sensing properties are determined. The materialcan be applied to create sensing artificial muscles.What aspects of this project do you find most exciting?