Low-voltage and low-power field-ionization gas sensor based on micro-gap between suspended silver nanowires electrodes for toluene detection

Abstract

We have demonstrated field-ionization gas sensor using suspended silver nanowires as electrodes. The tight gap of 1.5 μm between two facing sets of suspended in-plane nanowires on top of silicon microelectrodes, as well as the sharp protrusion of nanowires, allows the generation of high and non-uniform electric field. This produces field emission of electrons that result in ionization of gas molecules at a very low voltage applied. The fabricated sensor could detect toluene at 1.5 V of operational voltage, which is 10 times lower than the existing ionization gas sensors. Resultantly, extremely low power consumption of 75 nW for toluene sensing is also achieved, which implies the proposed field-ionization gas sensor could be a strong candidate for mobile device application.