Development of hazardous gas sensors based on ultra-low power and highly reliable nanoheater

Abstract

The major challenges restricting the semiconducting metal-oxide gas sensors to be implemented in mobile devices have been the high energy usage of microheaters and low reliability of fabrication that does not meet the industry-level. In this paper, we propose a perfectly-aligned nanowire array as a basic heater element to overcome the prevailing power consumption issue of microheaters, and the developed heater platform was monolithically integrated with gas sensing nanowires to demonstrate its full utility as the gas sensing devices. The proposed structure significantly suppressed heat loss through beam conduction, which enables achieving unprecedented ultra-low power operation surpassing the conventional limits. Prior to employment the nanomaterials, reliable fabrication technologies applicable to the industry-level were developed

the uniformity of thin-film based devices batch-fabricated in a large area was evaluated. By simply replacing the flat substrate to a nanograting substrate, we successfully demonstrated ultra-low power and highly reliable nanoheater integrated gas sensors composed of the perfectly-aligned nanowire array. The heater provided the required temperature to activate the gas sensing mechanism with less than 5 mW, and the sensor was able to detect 1 ppm of low concentration of carbon monoxide gas. The present techniques offer a promising pathway toward realizing always-on gas sensors driven by battery-powered mobile devices, which will ensure a hazardous gas-free safe environment in our daily life.