Please use this identifier to cite or link to this item:
Title: Characterization of proton irradiated copolymer thin films for microelectromechanical system applications
Authors: Lam, Tin-yan
Lau, Sien Ting
Chao, Chen
Chan, Helen L. W.
Choy, Chung-loong
Cheung, W. Y.
Wong, S. P.
Subjects: Polymer blends
Polymer films
Proton effects
Light interferometry
Issue Date: 25-Jan-2007
Publisher: American Institute of Physics
Source: Applied physics letters, 25 Jan. 2007, v. 90, 043511, p. 1-3
Abstract: The electrostrictive response of proton irradiated poly vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] thin films, deposited on silicon (Si) substrates, has been characterized. By applying an ac field to the copolymer films, the induced surface displacement of the film along the thickness direction was measured using a laser interferometer. After the proton irradiation, the electric field induced strain response of the copolymer film is enhanced. Since the copolymer films are laterally clamped by the rigid substrate, the films cannot vibrate freely. At a proton dose of 50 Mrad, the effective electrostrictive coefficient M[sub eff,33] of P(VDF-TrFE) thin film on Si is 0.07 10[sup -18] V²/m² which is ~25 times smaller than that of bulk sample under the same irradiation dose (M[sub 33]=1.76x10[sup −18] V²/m²). Using bulk micromachining to etch away most of the Si substrate, an actuator in the form of a suspended membrane was fabricated. The effective electrostrictive coefficient at the center of the membrane M[sub eff,33] increased to 0.67x10[sup −18] V²/m² due to the weakening of the substrate clamping effect. The resonance characteristics of the actuators based on these irradiated copolymer films were studied.
Rights: © 2007 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in T.Y. Lam et al. Appl. Phys. Lett. 90, 043511 (2007) and may be found at
Type: Journal/Magazine Article
ISSN: 0003-6951
Appears in Collections:MRC Journal/Magazine Articles
AP Journal/Magazine Articles

Files in This Item:
File Description SizeFormat 
microelectromechanical_07.pdf177.38 kBAdobe PDFView/Open

All items in the PolyU Institutional Repository are protected by copyright, with all rights reserved, unless otherwise indicated. No item in the PolyU IR may be reproduced for commercial or resale purposes.