This paper presents the synthesis and characterisation of ZnO nanowire array using hydrothermal method. Synthesis of nanowire array on Elgiloy, a metallic alloy substrate was carried out for two different durations (5 hours and 10 hours) and characterised using Scanning Electron Microscope (SEM) to study the effect of growth duration on nanowire morphology. The SEM image indicated tapering of nanowire tip for growth duration of 10 hours. The as-synthesised nanowire array was tested for its performance as a pressure sensor using a laboratory test set-up with a fully blown balloon. This study demonstrates that the hydrothermally grown nanowire array is a good candidate for the development of pressure sensors.