Directed Assembly of Metal Oxide Nanobelts With Microsystems Into Integrated Nanosensors

Single-crystalline tin dioxide (SnO2) nanobelts have been assembled with microfabricated suspended heaters as low-power, sensitive gas sensors. With less than 4 mW power consumption of the micro-heater, the nanobelt can be heated up to 500°C. The electrical conductance of the heated nanobelt was found to be highly stable and sensitive to toxic and inflammable gas species including dimethyl methyl phosphonate (DMMP), nitrogen dioxide (NO2), and ethanol. The experiment is a step towards the large scale integration of nanomaterials with microsystems, and such integration via a directed assembly approach can potentially enable the fabrication of low-power, sensitive, and selective integrated nanosensor systems.