ABSTRACT
Microelectromechanical Systems (MEMS) based metal-to-metal ohmic contact switches show many advantages in comparison to solid-state switches, such as lower power consumption, smaller size, less weight, lower insertion loss, etc. [1,
2]. MEMS ohmic contact switches are commercially available and their reported lifetime is improving each year [3, 4]. However, there are currently no analyses or models which can predict or estimate contact performance as a function of number of switch cycles or which would enable the characterization of switch lifetime performance and behavior. This is due to lack of experimental data which could enable the development of such model(s). Previous studies have investigated the performance of micro-contacts in the pristine state (e.g., [5]), but only a limited number of studies have investigated the mechanics of microcontact under cyclic condition (i.e., during their operation) or have made measurements of microcontact parameters (e.g., [6, 7]). Maugis studied the separation mechanics of contacts in terms of surface forces, deformation, etc. [8, 9]. Chen used silicon cantilevers coated with contact material in a Scanning Probe Microscope setup and studied adhesion and modes of microcontact separation [10, 11]. Gregori et al. used a nanoindenter to monitor changes in contact adhesion of an actual microswitch [7]. Dickrell and Dugger used a nanoindenter with a 3.2 mm diameter probe to study resistance degradation under the hot-switching condition [12]. The physical and electrical processes involved over the lifetime of metal-to-metal microcontacts have also been reported [6, 13-15].
