Mirror Magic: Mapping Material Stiffness with Light and Magnets

Meet the Optomagnetic Micromirror Arrays (OMA), a unique tool designed to figure out how stiff biomimetic materials are, even on a tiny, cellular level. Picture this: a 5. 1 by 7. 2 millimeter field filled with 50, 000 teeny-tiny magnetic mirrors, each with optical grating structures and coated with an elastic PDMS film. These mirrors are topped with biomimetic materials. When hit with a broadband white light beam, they reflect microscale rainbow light rays. Here's where it gets interesting: apply a magnetic field, and each mirror tilts differently based on the local stiffness of the materials above it. By capturing specific narrow bands of reflection light with low N. A. optics, researchers can tell how stiff the materials are by the color changes they see on the mirrors. This method offers a high-speed, high-detail way to map stiffness across tissues while keeping the resolution down to individual cells.