Fall 2010 IAB
September 15 to 17
A Gas Sensor Based on Tunneling Field Ionization on
Tailored Nanoneedle Arrays
E-Noses employ an array of gas detectors each tailored to respond differently to a range of chemicals. In the presence of a particular gaseous compound, the responses of sensors form a signature that is analyzed in the signal transduction process. This method of detection mimics the function of mammalian noses. The gas sensing cells operate by a variety of fundamentally different mechanisms, but generally, catalyst based sensors suffer from issues such as poor selectivity and slow response time. This talk will introduce a novel highly selective sensing technology that fingerprints gases based on their unique ionization characteristics such as field ionization threshold and electric breakdown voltages. We designed and fabricated devices by synthesizing silicon nanowires with ultra-sharp tips to provide strong electric field at their tips to assist the rapid gas ionization process at very low bias voltages.