Modeling in-plane misalignments in lateral combdrive transducers

• Published in: Journal of micromechanics and microengineering Vol. 13; no. 6; pp. 809 - 815
• Main Authors: Avdeev, Ilya V, Lovell, Michael R, Jr, Dipo Onipede
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.11.2003; Institute of Physics
• Subjects: Exact sciences and technology; General equipment and techniques; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mechanical instruments, equipment and techniques; Micromechanical devices and systems; Physics; Transducers; Interdigital transducers; Capacitive transducer; Pull in voltage; Numerical method; Micromachine; Finite element method; Three dimensional model; Virtual work principle; Analytical method; Modelling; Miniaturization; Alignment defect; Microelectromechanical device
• ISSN: 0960-1317; 1361-6439
• DOI: 10.1088/0960-1317/13/6/303

The misalignment of lateral combdrive fingers was studied using analytical and finite element modeling techniques. Based on the principle of virtual work, the required driving force, and the forces and moments that develop during in-plane combdrive misalignment were analytically calculated. Electrostatic uncoupled 2D and 3D finite element models were then used to perform energy computations during misalignment. Finally, a stability analysis of misaligned combdrive fingers was performed using a coupled 2D finite element approach. The analytical and numerical results were compared and found to vary due to fringing in the electrostatic fields. The significance of the fringing fields and stability equilibrium states were subsequently discussed with respect to the design of precision MEMS devices.