NEMS diaphragm sensors integrated with triple-nano-ring resonator

Abstract

Two types of circular diaphragm, made by Si and Si/SiO2, integrated with hexagonal photonic crystal (PhC) lattice with triple-nano-ring (TNR) resonator created at the centre are proposed as nano-scale force and pressure sensor. The optimized channel drop effect of the TNR resonator brings a strong forward drop resonant peak in both the cases and with Q-factor of 1602 and 1737, respectively. The resonant wavelength peak experience red shifts upon the applied load on the circular diaphragm along the normal direction, in terms of a 2nd-order polynomial relationship. The devices can detect a wide range of applied load. Si diaphragm based micro force sensor gives minimum detectable force of 0.847 μN in the region of applied force from 10 to 20 μN. Si/SiO2 diaphragm based pressure sensor gives minimum detectable pressure of 4.17 MPa in the region of applied pressure from 20 to 40 MPa. From the derived wavelength shift versus a given centre displacement of the diaphragm, Si diaphragm based sensor shows higher sensitivity than Si/SiO 2 diaphragm sensor. © 2011 Elsevier B.V. All rights reserved.