Asymmetric Bilayer Muscles. Cooperative and Antagonist Actuation. (20th March 2016)

• Record Type: Journal Article
• Authors: Fuchiwaki, Masaki; Martinez, Jose G.; Otero, Toribio F.
• Is Part Of: Electrochimica acta. Volume 195(2016)
• Page Start: 9
• Page End: 18
• Publication Date: 2016-03-20
• Subjects: Conducting polymer -- Asymmetric bilayer muscle -- Cooperative actuation -- Antagonist actuation; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2016.02.104
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Highlights: Bilayers CPi /tape and the asymmetric bilayer CP1 /CP2 have been constructed and characterized. Coulo-dynamic (charge-angle) responses give reaction-driven ionic exchanges during actuation. Synergic and cooperative dynamical effects of the two constitutive CPs layers improve actuation. Antagonist effects from the two constitutive CPs layers reduce the actuation amplitude. Abstract: Thick films of polypyrrole-paraphenolsulfonic acid (PPy-HpPS), polypyrrole-dodecylbenzensulfonic acid (PPy-DBS) and a bilayer PPy-HpPS/PPy-DBS (asymmetric bilayer) were electrogenerated from aqueous solutions. Two bilayers: PPy-HpPS/tape and tape/PPyDBS were constructed. The angular displacement of those three bilayer muscles was characterized in NaCl aqueous solution by cyclic voltammetry and parallel video recording of the bending movement. The attained coulo-voltammetric (charge-potential), dynamo-voltammetric (angle-potential) and coulo-dynamic (charge-angle) responses until different cathodic potential limits were analyzed. The dynamo-voltammetric and coulo-dynamic responses from the PPy-HpPS/tape and tape/PPyDBS muscles inform about the reaction driven ionic exchanges in the two PPy films. Electrochemo-dynamical responses from the asymmetric PPy-HpPS/PPy-DBS bilayer muscles are explained using those reactions. Cooperative dynamic effects exist when both layers follow complementary reaction-driven volume changes (swelling/shrinking, or shrinking/swelling) due to complementary entrance/expulsion of ions. The cooperative amplitude of the angle described by the asymmetric bilayer muscle is one order of magnitude larger than those attained from each of the conducting polymer/tape bilayer muscles. Antagonist dynamic actuation occurs when the two films swell, or shrink, simultaneously originating narrower angular displacements. Improving cooperative actuation or eliminating antagonist actuation and creeping by suitable selection of polymers and electrolytes seem the way to get most efficient polymeric motors and industrial products.