Design and Characterization of a MEMS Thermal Actuator and a Locking Switch for Telecommunication Applications

D. Dellaert, J. Doutreloigne
Ghent University, BE

Keywords: MEMS, thermal actuator, locking switch, automated distribution frame

Summary:

This paper describes the design and characterization of a novel thermal actuator used in a locking switch. Because of the locking mechanism, no energy is needed to stay in the open or closed state. The switch can be used in an automated MEMS-based distribution frame for telecommunication networks. The proposed thermal actuator achieves asymmetric heating by a polysilicon resistor underneath the structural layer, making a high drive resistance while still obtaining a low resistivity signal path in nickel. Making use of a nitride connection, both thermal and electrical isolation is achieved. With a drive resistance of more than 1kohm, displacements up to 70μm are possible at 14V. By placing two of the proposed actuators perpendicular to each other, a locking switch can be obtained. The contacts were plated with gold, resulting in an on-resistance of 0.35ohm. This contact resistance remains below 2ohm, even after 10^5 cycles and a measuring current of 50mA. The breakdown voltage of the switch was measured to be in the range of 450V-600V.