An in-plane thermal unimorph using confined polymers

Journal article (2007)

Authors

GK Lau Computational Design and Mechanics - Mechanical, Maritime and Materials Engineering
T Chu Duc Electronic Components, Technology and Materials - EEMCS
J.F.L. Goosen Computational Design and Mechanics - Mechanical, Maritime and Materials Engineering
Pasqualina M Sarro Electronic Components, Technology and Materials - EEMCS
A. van Keulen Computational Design and Mechanics - Mechanical, Maritime and Materials Engineering
Research Group
Computational Design and Mechanics (Mechanical, Maritime and Materials Engineering) (TU Delft)
Elektrotechniek Techniek
More Info
expand_more

Published Date

2007

Language

Undefined/Unknown

Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Faculty

Mechanical, Maritime and Materials Engineering

Department

Precision and Microsystems Engineering

Research Group

Computational Design and Mechanics

Abstract

This paper presents the design, simulation and characterization of a new type of in-plane thermal unimorph, which utilizes composite SU-8/silicon microstructures. The unimorph consists of a silicon skeleton and SU-8 photoresist, which encapsulates the silicon skeleton. The silicon skeleton is asymmetric in shape, consisting of a straight segment and a meandering segment. Gaps and surrounds of the skeleton are filled with the SU-8 polymer. Bonds between the polymer filling and the sidewalls of the silicon microstructure enhance thermal expansion and stiffness of the polymer in a transverse direction. Therefore, this unimorph design delivers excellent actuation performance. The composite actuator bends laterally when electro-thermally activated. A 530 µm long, 90 µm wide and 50 µm thick micro-machined device achieves a maximum lateral displacement of 25 µm at a 1.75 V driving voltage and at 17.8 mW input power, at an average temperature below 200 degrees C. It has a simulated lateral stiffness of 1.2 kN m-1. At 1.75 V, it is estimated to produce a 30 mN lateral blocked force that is high compared to other micro-actuators.