Topology Optimization of Stressed Capacitive RF MEMS Switches

• Published in: Journal of microelectromechanical systems Vol. 22; no. 1; pp. 206 - 215
• Main Authors: Philippine, M. A., Sigmund, O., Rebeiz, G. M., Kenny, T. W.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.02.2013; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Circuit properties; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Geometry design; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; intrinsic stress; mechanical design; Mechanical instruments, equipment and techniques; Micromechanical devices and systems; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Optimization; Physics; Radio frequency; radio-frequency microelectromechanical systems (RF MEMS); Sensitivity; Solids; Stress; stress gradient; Switches; Topology; topology optimization; Membranes; radio-frequency microelectromechanical systems (RF MEMS); stress gradient; Geometry design; Capacitive transducer; Switches; Topology; Radiofrequency; Electrostatic devices; Optimization; mechanical design; Strain gradient; Microwave circuits; intrinsic stress; topology optimization; Reliability; Microelectromechanical device
• ISSN: 1057-7157; 1941-0158
• DOI: 10.1109/JMEMS.2012.2224640

Geometry design can improve a capacitive radio-frequency microelectromechanical system switch's reliability by reducing the impacts of intrinsic biaxial stresses and stress gradients on the switch's membrane. Intrinsic biaxial stresses cause stress stiffening, whereas stress gradients cause out-of-plane curling. We use topology optimization to systematically generate designs, by minimizing stress stiffening, minimizing curling, or minimizing stress stiffening while constraining the curling behavior. We present the corresponding problem formulations and sensitivity derivations and discuss the role of key elements in the problem formulation.