Active opening force and passive contact force electrostatic switches for soft metal contact materials
2006 (English)In: Journal of microelectromechanical systems, ISSN 1057-7157, E-ISSN 1941-0158, Vol. 15, no 5, 1235-1242 p.Article in journal (Refereed) Published
This paper reports on a mechanically bi-stable, electrostatically actuated switch mechanism with a large active opening force and a small passive closing force, designed to fit the contact and opening force requirements of soft contact materials such as gold. So far, most microelectromechanical systems (MEMS) switch designs have been optimized for a large contact force without paying too much attention to the opening force. In the conventional, most commonly used electrostatic microswitch concept, the force of the actuator is used to close the switch contacts, and the switch is opened by the passive restoring force of the deflected cantilever or membrane. This concept results in a large contact force, but the opening force is typically too small to overcome the contact adhesion force of soft metals, which makes this concept less suitable for contact materials such as gold with its low contact resistance at low contact forces. The switch concept presented in this paper is based on two cantilevers laterally moving by curved electrode actuators. The tips of the cantilevers are endowed with hooks which can be mechanically interlocked. In the latched state, the spring forces of the deflected cantilevers also act as the passive contact force between the switch contacts. The opening force is actively created by the curved-electrode actuators, which are utilized close to their best electromechanical operating point resulting in a maximum contact separation force. The theoretical discussion of the new concept as compared to conventional switch designs is supported by simulation results, measurements on fabricated devices, and by an analysis of exemplary switches published in the literature.
Place, publisher, year, edition, pages
2006. Vol. 15, no 5, 1235-1242 p.
contact material, curved-electrode actuator, microelectromechanical systems (MEMS) switch, microswitch, RF MEMS, mems switches, actuators, gold
IdentifiersURN: urn:nbn:se:kth:diva-16075DOI: 10.1109/JMEMS.2006.882810ISI: 000241410600022ScopusID: 2-s2.0-33750004656OAI: oai:DiVA.org:kth-16075DiVA: diva2:334117
QC 201005252010-08-052010-08-05Bibliographically approved