(583d) Flow-Guided Template Manufacturing of Nanowire-Array Sensors

Nanowires hold tremendous potentials to build next-generation sensors, electronics, and optoelectronics. Compared to the thin film planar counterparts, these devices better define the accumulation or depletion of charge carriers to attain ultrahigh sensitivity. However, their wide adoption is seriously impeded from the great challenges on the fabrication, integration, and manufacturing of nanowire-based electronics. We adopt microchannel-based templates in the fabrication of nanowire-based sensing system. A novel flow-guided assembly approach we invented, in which polymer strands are aligned and patterned along microchannels via air blowing to produce highly ordered nanowire arrays with each nanowire centimeter long and having tunable diameter.  The polymer nanowires were further converted to carbon, following a procedure which has used for years in the production of carbon nanofibers in industry. Unlike in other template synthesis processes where nanowires are randomly distributed on sensing substrates, our approach pre-defines the position and patterns of nanowires at desired locations (e.g., between the contact micropads). We are now working on its sensing performance on proteins after being built as nanowire field emission transistors. Their small lateral size, high surface-to-volume ratio, and tunable quantum confinement effect demonstrate nonlinear behaviors on the mobility of carriers and ultrahigh sensitivities.