Miniaturized Plasmonic Sensor With Dual-Function Capability for Pressure and Flow Rate Detection at Subwavelength Levels

This article introduces a nanoscale plasmonic sensor with dual-function capabilities for detecting both pressure and flow rate, designed using a metal-insulator–metal (MIM) bus waveguide coupled with a resonator featuring a horizontal slot and multiple stubs. The sensor demonstrates high pressure sensitivity, achieving 1100.70 nm/MPa for pressure detection, with a figure of merit (FOM) of 4.6054, and effectively measures flow rates from 58.544 to 356.43 pL/s using an optical spectrum analyzer (OSA). Finite-element method (FEM) simulations were employed to analyze the pressure-induced wavelength shifts, enhancing the sensor’s versatility in integrated sensing applications. The sensor’s compact footprint, simplicity, and ease of fabrication make it ideal for integration into laboratory-on-a-chip devices. Its dual functionality provides a novel solution for precise, real-time monitoring in biomedical and microfluidic engineering applications.