ZnO Nanowire Embedded Strain Sensing Cantilever: A New Ultra-Sensitive Technology Platform

A novel ultra sensitive micro-cantilever-based technology platform was developed in this letter for strain sensing applications. Sensing mechanism is based on electrical conduction through the ZnO nanowires embedded inside a SU-8 polymer cantilever beam. The lower Young's modulus of the polymer and the higher strain sensitivity of ZnO nanowires are used to improve the performance of these micro-cantilever devices. Deflection sensitivity of this technology is measured to be 128 ppm/nm. Besides the electromechanical characterization, mechanical characterization has also been performed to measure the resonant frequency of these microcantilever devices, which is shown to be in a few tens of kilohertz range, suitable for nanomechanical sensing applications.