Silicon Electrothermal Microactuators as Zero Standby Power Local Temperature Switches

The bent-beam structure is a well-known elec-trothermal actuator based on asymmetric thermal expansion, but is less commonly used for sensors. In this work, a silicon-based bent-beam structure was fabricated on Silicon-on-Insulator (SOl) wafers to realise a local temperature-sensitive switch. The novel sensor-switch closes a
$0.7\mu \mathrm{m}$
gap when locally heated above 80°C, yet is unperturbed when the ambient temperature is raised up to 150°C. We used thermal imaging to analyse the temperature distributions for different heating schemes and modelled the results with finite-element simulations. The results show that these structures are attractive candidates for zero standby power, surface-sensitive temperature switches.