Site-specific growth and in situ integration of different nanowire material networks on a single chip: towards a nanowire-based electronic nose for gas detection

A new method for the site-selective synthesis of nanowires has been developed to enable material growth with defined morphology and at the same time different composition on the same chip surface. The chemical vapour deposition approach for the growth of these nanowire-based resistive devices using micromembranes can be easily modified and represents a simple, adjustable fabrica-tion process for the direct integration of nanowire meshes in multifunctional devices. This proof-of-concept study includes the deposition of SnO2, WO3 and Ge nanowires on the same chip. The individual resistors exhibit adequate gas sensing responses to-wards changing gas concentration of CO, NO2 and humidity diluted in synthetic air. The data have been processed by principal component analysis with cluster responses that can be easily separated and thus the devices described herein are in principle suita-ble for environmental monitoring.