Numerical study of near-optimal parameters of polymeric encapsulation layer containing a periodic array of piezoelectric nanowires used for force sensing

This paper presents the results of finite element modeling and analysis of a dynamically loaded array of individually addressable vertical ZnO nanowires (piezo-pixels) encapsulated in a polymer, which is intended to function as a pressure sensor having the purpose of identification of fingerprints with very high spatial resolution. Two multiphysics models were implemented by formulating different conditions of mechanical interfacial coupling between the nanowires and the surrounding polymer (with and without contact interactions). Parametric simulations were conducted in order to predict near-optimal values of polymer Young's modulus and layer thickness in terms of magnitude and variability of electrical signals generated by the nanowires. Numerical results also revealed the impact of different system parameters and load conditions on the electrical response of the nanowires.