A highly-compliant asymmetric 2D guided-mode resonance sensor for simultaneous measurement of dual-axis strain

We report the design, fabrication, and characterization of a high-resolution biaxial strain sensor based on guided-mode resonance (GMR) in a two-dimensional, asymmetric titanium dioxide nanograting embedded at the surface of a polydimethylsiloxane slab. The highly-compliant strain sensing technique used in this 2D GMR sensor relies on the shifting of the reflected resonant wavelengths, demonstrating a sensitivity of 4.8 nm/percent strain (%ε), which can be detected accurately by a high resolution spectrometer, thus providing exceptionally accurate strain measurements. To the best of our knowledge, this is the first demonstration of a 2D deformable GMR device, and the first demonstration of a 2D photonic strain sensor of this kind.