Low-Power and ppm-Level Multimolecule Detection by Integration of Self-Heated Metal Nanosheet Sensors

H₂ and NH₃ detection with low power consumption was demonstrated by integrated chemiresistive Pt and PtRh nanosheet sensors on glass substrates. The self-heating effects realized low power and local heating of metal nanosheet sensors, enabling the integration of sensors with different operating temperatures. Based on different resistance changes in Pt and PtRh nanosheets toward H₂ and NH₃, the concentration of each gas was detected from a gas mixture by consuming around 1-mW power. For decreasing the power consumption and further integration of sensors, sensor scaling and pulsed operations were numerically and experimentally studied. In addition to good connectivity of metal nanosheet sensors to large-scale integration (LSI) circuits, improvements of the power consumption by sensor scaling were proven. The pulsed operations required for integrated sensor arrays maintained a sensor response, or a resistance change, of approximately 60%, even when the power consumption was reduced by 20%.