  Silicon nanowires (SiNWs) are known to exhibit large piezoresistance (PZR)
effect, making it suitable for various sensing applications. Here, we report
the results of a PZR investigation on randomly distributed and interconnected
vertical silicon nanowire arrays as a pressure sensor. The samples were
produced from p-type (100) Si wafers using a silver catalysed top-down etching
process. The piezoresistance response of these SiNW arrays was analysed by
measuring their I-V characteristics under applied uniaxial as well as isostatic
pressure. The interconnected SiNWs exhibit increased mechanical stability in
comparison with separated or periodic nanowires. The repeatability of the
fabrication process and statistical distribution of measurements were also
tested on several samples from different batches. A sensing resolution down to
roughly \SI{1}{\milli\bar} pressure was observed with uniaxial force
application, and more than two orders of magnitude resistance variation was
determined for isostatic pressure below atmospheric pressure.
