A Mems Zero Power Crop Water Stress Detector Based on Thermal Infrared Sensing

This paper reports on the first micromechanical photoswitch-based thermal-infrared sensor capable of detecting water-stress in a live plant while consuming nearzero standby power. The sensor selectively harvests the thermal radiation emitted from the leaves of a waterstressed plant and uses it to generate a digitized-output-bit. In particular, a SiO2/Pt stack was employed in the sensor as the broadband long-wavelength-infrared absorber centered at~10.6μm with a measured peak absorption~88%. The sensor was triggered only when the plant started showing water-stress (a temperature increase of 3.6°C when the relative-water-content dropped to 61%), while remaining dormant with zero-power consumption when the plant was healthy.