The
selective fabrication of highly ordered nanowires with high
aspect ratios was of low reproducibility, which remains a challenge
for laboratory research. In this paper, we report a novel approach
for selective fabrication of conductive nanowires on a solid surface
via diffusion mixing reaction system formed by a chemical pen. The
nanoscale-mixing region was achieved by appropriately adjusting the
viscosity of the solution and other parameters with the aid of dyes
functioned as a flow boundary indicator. Finite element simulations
and analysis were performed to understand the generation of mixing
regions and guide the improvement of the chemical pen design. Under
the optimal parameters, high aspect ratio silver nanowires (aspect
ratio ≈ 1800) were obtained. Silver nanowire arrays with uniform
width, gradient width and complex patterns were successfully fabricated.
The theoretical value of the temperature coefficient of resistance
(TCR) for silver was 0.0038 Ω/°C. A single silver wire
temperature sensor with 7-fold increase in temperature coefficient
resistance (0.0261 Ω/°C) was fabricated to show the advantages
of the chemical pen in the fabrication of nanosensors. With the freedom
of the region, simple operability and applicability, the chemical
pen was expected to a potential and advanced method for selective
nanomodification and processing on subcellular interfaces.