Plastic Deformation Study of Vertical Zinc Oxide Nanowires for Polymer Cantilever-Based Sensor Applications

In this letter, the mechanical properties of piezoelectric ZnO nanowire (NW) films have been measured using a nanoindentation technique. We demonstrated a fabrication process to embed this NW film inside a polymeric (SU-8) cantilever. Mechanical properties of this SU-8/ZnO NW film and cantilever have been measured. The ZnO NWs have been grown vertically using a low-temperature chemical synthesis. The observed value of Young's modulus for ZnO NW is in the range 72–93 GPa. After embedding this NW film inside a polymer matrix, the Young's modulus value was reduced to the range 5–19 GPa. The mechanical behavior of the NW-embedded cantilever has also been investigated using the nanoindentation technique. These cantilevers have been shown to be suitable for surface stress-sensing applications.