Abstract
Common quasi-static electrostatic micro actuators have significant limitations in deflection due to electrode separation and unstable drive regions. State-of-the-art electrostatic actuators achieve maximum deflections of approximately one third of the electrode separation. Large electrode separation and high driving voltages are normally required to achieve large actuator movements. Here we report on an electrostatic actuator class, fabricated in a CMOS-compatible process, which allows high deflections with small electrode separation. The concept presented makes the huge electrostatic forces within nanometre small electrode separation accessible for large deflections. Electrostatic actuations that are larger than the electrode separation were measured. An analytical theory is compared with measurement and simulation results and enables closer understanding of these actuators. The scaling behaviour discussed indicates significant future improvement on actuator deflection. The presented driving concept enables the investigation and development of novel micro systems with a high potential for improved device and system performance.
Highlights
Common quasi-static electrostatic micro actuators have significant limitations in deflection due to electrode separation and unstable drive regions
In the approach we present here, the high electrostatic forces generated by small electrode gaps are transformed into high deflection magnitudes
The role of the elementary actuator cells is to transform the electrostatic forces into lateral mechanical forces, which leads to a bending of the cantilever
Summary
Common quasi-static electrostatic micro actuators have significant limitations in deflection due to electrode separation and unstable drive regions. Recent publications have reported various attempts to enhance the controllable travelling range of static or quasi-static out-of-plane operating electrostatic actuators[4] Among these are electrical control strategies[7], leverage methods[8], active or passive suspension spring stiffening methods[9,10], mechanical non-linearities within the actuated micro component[11,12], a non-constant electrode separation[13,14] and the usage of electrostatic fringing fields[15]. With this novel electrostatic actuator concept, the cantilever tip deflection depends on electrostatic forces instead of the electrostatically generated electrode deflection This enables reasonable actuator deflection to be achieved with very small electrode separation, and enables travel ranges widely beyond the pull-in limit. The concept proposed of a novel electrostatic actuator class operates with electrode gaps far below micrometre, will be referred to as nano electrostatic drive (NED)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
