Linear sensing actuators of polypyrrole nanofiber scaffolds

In the search for renewable materials for linear actuators, polypyrrole (PPy) glucose-glycerin nanofiber scaffolds were used here to provide the actuator with a basic fibrillary structure, mimicking natural muscles. Each nanofiber was coated with a chemically synthesized PPy film, getting conductive nanofiber scaffolds (CNS), used then as electrodes to attain a second polypyrrole doped with dodecylbenzensulfonate (PPyDBS) coat forming PPyDBS-CNS material structure. PPyDBS bulk films obtained by electropolymerization on stainless steel under the same condition were used to compare the linear actuation properties of both materials. Cyclic voltammetry, square potential waves, and square potential currents, in combination with linear actuation measurements, studied the samples. Three different potential ranges (PRs) were selected for those methodologies: 1.0 to -0.55 V (PR1), 0.8 to -0.4 V (PR2), and 0.65 to -0.55 V (PR3), revealing that PPyDBS-CNS has anion-driven actuation independent of the applied PR1-3, while in comparison PPyDBS films had in PR3 mixed ion actuation. The best strain from PPyDBS, 24.6%, was attained at PR1, and from PPyDBS-CSN, 17.5% strain in the same PR. Further characterizations are conducted, such as scanning electron microscopy, Fourier transform infrared spectroscopy, and element determination using energy dispersive x-ray spectroscopy. PPyDBS and PPyDBS-CNS with SEM images (scale bar 10 mu m) and strain potential E curves at potential range PR1-3 of PPyDBS and PPyDBS-CNS. image