Numerical Modeling of an Integrable and Tunable Plasmonic Pressure Sensor with Nanostructure Grating

Plasmonic pressure sensors play a major role in advanced applications due to their unique properties including their small footprint and high sensitivity. The design of sensors with a wide pressure range and high sensitivity, especially at low pressure (0–5 KPa), is in high demand. To this end, here, a tunable, ultra-sensitive and wide-range plasmonic pressure sensor based on nanostructure gratings is proposed. We present a numerical method for designing a pressure sensor based on surface plasmon resonance (SPR) that can adjust the coupling state by varying the surface of the metal grating. The design is based on grating coupling changes according to the pressure applied. We used grating coupling for phase matching between light and surface plasmon polaritons (SPP). The light reflection output from the grating surface is proportional to the input pressure, where we illustrate that the SPR pairing state can be controlled by varying the grating pitch by changes in pressure applied to the diaphragm. In our numerical simulation, we consider solid deformation and transmission or reflection of light using the finite-difference time-domain (FDTD) and finite element method (FEM) to simulate the optical and mechanical properties, respectively. The many advantages of the proposed sensor include nanoscale, integrability, tunability, low power, low cost and wide pressure range. This sensor is capable of detecting pressure in the range of 0–1 kPa.