Harnessing self-heating in nanowires for energy efficient, fully autonomous and ultra-fast gas sensors

Self-heating effects in large arrangements of randomly oriented carbon nanofibers: Application to gas sensors

“…This so-called self-heating effect has been already studied in nanosized gas sensor devices [16][17][18][19][20], achieving very low power figures. Specifically, self-heating was first proven in one single SnO 2 nanowire, obtaining reliable devices operated with less than 10 W [18][19][20][21][22].…”

“…This so-called self-heating effect has been already studied in nanosized gas sensor devices [16][17][18][19][20], achieving very low power figures. Specifically, self-heating was first proven in one single SnO 2 nanowire, obtaining reliable devices operated with less than 10 W [18][19][20][21][22]. To the best of our knowledge, self-heating has further been studied in sensor devices with highly ordered nanostructures, such as suspended nanowires [15,19,20], or catalytically activated materials [17].…”

Localized self-heating in large arrays of 1D nanostructures

“…Before imaging, the temperature reached in self-heating operation was calibrated by monitoring the CNFs film resistance and comparing the values obtained with the heater with those obtained with self-heating. Using this standard procedure 20,25,[31][32][33][34] , the nominal self-heating temperature was that of the heater at an equivalent resistance drop. Figure 1a shows the thermal images of the CNFs film at 100 °C reached with self-heating and heater.…”

“…Later, advancements in low power instrumentation 14 showed that it was possible to control the selfheating level to the point that it could be used to set the temperature at the nanoscale, without additional heating components 15,16 . In fields requiring temperature control, such as solid state gas sensing, integrating both heating and sensing functionalities in the nanowire itself was a remarkable advantage 17 . More importantly, studies revealed that the self-heating effects in individual nanowires could be used to lower the power consumption figures more than 1000 times compared to state-of-the art microdevices 15 , due to the small dimensions of the volume heated in the nanowire.…”

“…First works with individual nanowires proposed that the minute dimensions of the structures lead to remarkably high Joule-dissipated power densities in the nanostructure, even at very low current/voltage levels. Also, the small contacts with the surroundings minimized thermal losses, providing the high thermal efficiency observed 15,17 . These arguments justified the need of individual nanostructures, and suggested that such effects were just unfeasible in large arrangements of nanowires 27 .…”