Multimaterial fiber microelectromechanical systems based on electrostrictive P(VDF-TrFE-CFE)

Abstract

The miniaturization of electromechanical transducers using bulk and surface micromachining processes has enabled the deployment of microelectromechanical systems (MEMS) in a variety of applications, from cell phones and ink-jet printers to drug delivery devices. A recently developed approach for the fabrication of multimaterial fiber devices presents a unique opportunity to realize MEMS in a novel form. In this paper a thermally drawn MEMS fiber device based on P(VDF-TrFE-CFE) ferrorelaxor terpolymer is presented. Electromechanical actuation capabilities of this fiber device are established with a maximum strain of 0.78% and a maximum transverse deflection of 7[mu]m under an applied voltage of 300VDC. The potential of this approach to realize complex electromechanical systems in fibers is illustrated by the fabrication of an electrostrictive device capable of modulating a light source reflected off the surface of the fiber. Amplitude modulation of incident light through electric field induced deflection is demonstrated up to the second harmonic frequency of the fiber at 158.3Hz, and a modulation depth of 22.5% is reported; for an array of such fibers in PDMS, amplitude modulation is demonstrated at low frequencies with a modulation depth of 25.8%. These results pave the way to the realization of sophisticated MEMS in fiber, with potential applications in large surface area devices such as interactive haptic displays, acoustic modulators, and energy harvesting systems.