TY - JOUR N1 - Compilation and indexing terms, Copyright 2010 Elsevier Inc. M1 - Compendex TI - A high-aspect-ratio two-axis electrostatic microactuator with extended travel range JO - Sensors and Actuators, A: Physical A1 - Sun, Yu A1 - Piyabongkarn, D. A1 - Sezen, A. A1 - Nelson, B.J. A1 - Rajamani, R. AD - Department of Mechanical Engineering, University of Minnesota, 111 Church Street S.E., Minneapolis, MN 55455, United States VL - 102 IS - 1-2 PY - 2002 U1 - 2002517282362 SP - 49 EP - 60 SN - 09244247 PB - Elsevier N2 - The design, fabrication, modelling, and control of a two-axis electrostatic microactuator for precision manipulation tasks is described. A high-yield fabrication process using deep reactive ion etching (DRIE) on silicon-on-insulator (SOI) wafers forms the 3-D high aspect ratio transverse comb drives that produce a relatively large electrostatic force. The structure is suspended by removing the substrate beneath the comb drives, therefore, a ground plane is not needed in order to compensate for electrostatic levitation. Among other advantages of the developed process is a dice-free release of wafer structures, allowing fragile structures to be individually packaged. Notching or footing effects and bowing effects are well-known problems in DRIE on SOI wafers. Techniques to overcome notching and bowing effects using a PlasmaTherm SLR-770 etcher are presented that do not require hardware modifications. A capacitive position sensing mechanism, capable of measuring displacements up to 4.5 m with a resolution of 0.01 m in both X and Y is integrated to provide position feedback. A nonlinear model inversion technique is proposed for nonlinear electrostatic microactuation system identification and improving system linearity and response. Pull-in instability limits the travel distance of transverse comb drive actuators. Using a nonlinear model inversion technique, a stable travel distance of 3.7 m with a 4.5 m gap has been achieved. 2002 Elsevier Science B.V. All rights reserved. KW - Electrostatic actuators KW - Aspect ratio KW - Atomic force microscopy KW - Microelectromechanical devices KW - Nonlinear control systems KW - Reactive ion etching KW - Silicon on insulator technology KW - Silicon wafers U2 - Deep reactive ion etching (DRIE) L2 - http://dx.doi.org/10.1016/S0924-4247(02)00298-4 ER -