Spencer Publishes MEM Switch Contact Research

Microelectromechanical (MEM) switches are tiny devices—imagine the diameter of a single strand of hair or smaller—that are crucial parts of cell phones and radios. A study of the changes in conductivity of specific types of MEM switch contacts is the subject of a paper co-authored by engineering professor Matthew Spencer and his students Ethan Falicov ’21 and Jessica Marvin ’23 (first and second author, respectively).

The paper “Breakdown and Healing of Tungsten-Oxide Films on Microelectromechanical Relay Contacts” was published in the Institute of Electrical and Electronics Engineers’ Journal of Microelectromechanical Systems.

“This work examined a type of MEM switch with tungsten contacts, which were used in this application to improve the endurance of MEM switch contacts,” says Spencer. “We observed that the resistance of tungsten contacts increases quickly in atmosphere, and we studied how to restore low resistance with electrical stress. This let us trace the source of these resistance changes, which occur because of the behavior of charge traps in tungsten oxides that form on the switch surfaces.”

While the current practical application of MEM switches is for cell phones and radios, Spencer says MEM switches with tungsten contacts could have high endurance, which could enable them to be used in new applications, like low-power computing.

“This work could be extended by studying the resistance changes at different temperatures or under different atmospheric conditions, like humidity or gas composition,” he says. “Studying the resistance change under these conditions could inform types of packaging and environmental sealing that improve MEM switch properties.”