AP3.1 - Silicon Nanowire Arrays for the Preconcentration and Joule Heating-Based Desorption of Trace Vapors
- 17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
- Applications 3 - Indoor Gas Sensing
- P. Pehrsson, B. Giordano, D. Ratchford, K. Johnson - Chemistry Division, Naval Research Laboratory, Washington, D.C. (USA)
- 380 - 381
We preconcentrated trace nitroaromatic vapors onto silicon nanowire (SiNW) arrays and desorbed them by Joule heating the array. The ordered arrays were fabricated by nanosphere lithography (NSL) combined with metal-assisted chemical etching (MACE). The nanowires had diameters of ~350 nm, lengths of ~5 μm, and center-to-center spacing of 500 nm. Each SiNW array chip was approximately 108 individual wires. The nanowires were Joule heated by passing a current along their lengths, and the nanowire temperature was measured using the shift of the Si Raman single phonon line. The adsorption and selective desorption of 2,4-dinitrotoluene (2,4-DNT) and similar trace vapors was evaluated by coupling the array to a mass spectrometer.