MIM waveguide optical accelerometer designed with a biomimetic radial stress structure inspired by spider webs

We propose and validate an optical accelerometer that couples a spider-web-inspired radial-stress topology with a metal-insulator-metal (MIM) waveguide readout. The device comprises a hierarchically coupled central proof mass, symmetric radial beams, and a hexagonal cavity; MIM waveguides are embedded at strain hot spots to excite high-slope Fano resonances, enabling amplified force-to-optical transduction and direction-selective two-dimensional readout. Two-dimensional FEM simulations (COMSOL) reveal three narrowband resonances in the near-infrared (859, 1104, and 1518 nm): the 1104 nm mode forms a circumferentially closed, strongly coupled loop suitable for primary <i>x</i>-axis readout, while the 859 nm mode localizes at the slit and cavity-beam junction, favoring high-sensitivity <i>y</i>-axis detection. Linear calibration yields, at 1104 nm, an <i>x</i>-axis sensitivity of 0.0228 nm/g with FWHM = 7.3 nm (FOM = 0.00312 g^-1, <i>Q</i> = 151.23); and at 859 nm, a <i>y</i>-axis sensitivity of 0.1731 nm/g with FWHM = 5.79 nm (FOM = 0.02989 g^-1, <i>Q</i> = 148.36), with coefficients of determination <i>R</i>² = 0.9796 and <i>R</i>² = 0.99, respectively. When temperature increases from 273.15 K to 373.15 K, both operating wavelengths exhibit only slight peak drifts and nearly unchanged linewidths, indicating excellent thermal stability and readout consistency. These results show that deeply integrating the bio-inspired topology with MIM resonances achieves multi-axis decoupling and compact manufacturability while preserving high <i>Q</i> and low noise, offering a scalable route to high-performance, nanoscale optical inertial sensing.