The compressive electrical field electrostrictive coefficient M₃₃ of electroactive polymer composites and its saturation versus electrical field, polymer thickness, frequency, and fillers

Abstract

Electroactive polymers are widely studied because of their large electrical‐field‐induced strain. Their flexibility and their ability to be deposited on large surfaces make them promising candidates as electroactive materials for actuators or energy‐harvesting devices. For actuation purposes, the material efficiency is directly related to the electrical‐field‐related electrostrictive coefficient M33 through S33 = M33E2, where S33 is the electrical‐field‐induced strain and E is the applied electrical field. Numerous studies concern the increase of M33, but very few have been devoted to its saturations versus electrical field. To this end, the present paper describes the variation of M33 versus thickness, composition, frequency, and electrical field for polyurethane‐based composites. Based on the saturation of the electrical‐field‐induced polarization within the studied polymer composites, a model of the M33 behavior was also proposed, and it was found to show a good agreement with the experimental data. In addition, this model predicts the dielectric constant and the saturation electrical field to be the key parameters ruling the M33 saturation. Copyright © 2011 John Wiley & Sons, Ltd.

Modeling of segmented pure polyurethane electrostriction behaviors based on their nanostructural properties

“…Thus, the films were embedded in an Epofix® resin and ultrathin sections were obtained by cryoultramicrotomy with a Reichert Ultracut S. The sample temperature was set to 200 K and the 35° diamond knife speed to 1 mm/s. The field-induced thickness strain Sexp was measured on circulars sample (25mm of diameter) with a homemade setup based on a double-beam laser interferometer measurement (Agilent 10889B) [15,16,17]. Samples were placed between two cylindrical brass masses acting as conductive electrodes.…”

Dielectric properties of segmented polyurethanes for electromechanical applications

“…polyurethane [224]. On the contrary, the Young's modulus is known to increase as a function of frequency because large translational motions are restricted and because relaxation processes can occur when the frequency is increased.…”

Electrostrictive Energy Conversion of Polyurethane with Different Hard Segment Aggregations

“…These properties allow PU to be used in numerous applications such as medical materials, sport goods, and coatings [1][2][3]. In the field of electroactive polymers, PUs are of great interest for actuation and energy conversion since they are capable of generating an electric-field-induced strain above 10% under an electric field 20 MV/m [4] and have an effective piezoelectric strain coefficient of 184 pC/N under a bias electric field of 25 MV/m comparable to that of a commercial piezoelectric PZT ceramic [5]. In addition, Guyomar and coworkers [6][7][8][9] proposed an analytical modeling based on the electrostrictive equations in order to explain the energy harvesting of PU elastomers, PU composites, and an electrostrictive poly(vinylidene fluoride-trifluoroethylenechlorofluoroethylene) terpolymer.…”