Actuation efficiency of polyvinylidene fluoride-based co- and ter-polymers. (7th November 2018)

• Record Type: Journal Article
• Authors: Lheritier, Pierre; Noel, Sébastien; Vaxelaire, Nicolas; Domingues Dos Santos, Fabrice; Defay, Emmanuel
• Is Part Of: Polymer. Volume 156(2018)
• Page Start: 270
• Page End: 275
• Publication Date: 2018-11-07
• Subjects: Electromechanical coupling -- Ter-polymer -- Thin films; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2018.10.003
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: Poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) (P(VDF-TrFE-CTFE)) ter-polymers reach strain up to 4% with the application of an electric field. This is several times larger than PVDF-TrFE co-polymers. However this large strain comes with reduced stiffness, which is detrimental to ter-polymers integration in heterogeneous structures. Here we compare the actuation capabilities of cantilevers with P(VDF-TrFE-CTFE) and P(VDF-TrFE) as active layer. Our ter-polymers exhibit CTFE composition ranging from 0 to 9.7%. We compared the electrical and mechanical displacements as well as the electromechanical coupling of these devices. We found that ter-polymer devices with CTFE ratio below 8% are ferroelectric whereas they become relaxor beyond 8% of CTFE. The maximum deflections of all cantilevers at high electric field are comparable, though slightly larger for the ter-polymer with 5% CTFE. The main finding of this paper concerns the effective electromechanical coupling of ter-polymers that is at best only half of the co-polymer one. Graphical abstract: Highlights: Below 8% CTFE, P(VDF-TrFE-CTFE) terpolymers are still ferroelectric. Terpolymers with a CTFE content around 5% possess the best performances at high electrical fields. The electromechanical coupling of terpolymer based actuator is half that of copolymer based ones.