Threshold scaling of near-zero power micromechanical photoswitches using bias voltage

This paper reports on the first experimental demonstration of threshold scaling of near-zero standby power micromechanical photoswitches with bias voltage. By leveraging electrostatic actuation, we show that the infrared (IR) power detection threshold of a plasmonically-enhanced micromechanical photoswitch (PMP) can be improved by over one order of magnitude (from ~1.3 μW to ~76 nW) while maintaining near-zero power consumption in standby. Such an improvement of threshold directly translates to an over 4 times increased detection range when the PMP is used for standoff detection of hot exhaust plume. Furthermore, the demonstrated technique also enables post-fabrication trimming of the device contact gap for achieving desired threshold, which is particularly useful for adapting the device to detect changing IR radiation. The unprecedented combination of near-zero standby power consumption and ultralow threshold of our PMP technology paves the way for the development of unattended IR sensor nodes with dramatically extended lifetime and detection range.