UCLA

The field of mechanobiology seeks to study the interplay between cellular biophysical properties and cellular health. Of particular interest to scientists is cellular stiffness, which has been shown to play a critical role in determining cellular state. For instance, researchers have discovered that cancer cells are less stiff than their benign counterparts, and they believe that this lower stiffness enables cancerous cells to invade benign tissues and adapt to new environments. As a result, profiling cellular biomechanical state can aid in disease diagnosis, making it a crucial research area in the biomedical field.Several methods have been proposed for measuring cellular stiffness, but most of them have limitations in terms of measuring a small number of cells or having low throughput. While isolated single cell mechanical property sensing can provide informative clues for detecting changes in cellular states or diseases, most disease developments involve collective cell migration and tissue reorganization. Therefore, measuring collective cellular stiffness or even at the tissue-level is crucial for gaining a more comprehensive understanding of the process. Here, my PhD research project aims to develop a device that we name “Optomagnetic Micromirror Arrays” (OMA) for steady state and real-time stiffness mapping for biomimetic materials with similar stiffness range to real biological tissues on a 5.1 mm x 7.2 mm field of view and with cellular resolution. This innovative device enables us to extract a large area of biomimetic material stiffness with single cellular resolution from the color spectra of an array of magnetic micromirrors, which are fabricated with sub-micron grating structures embedded in an elastic PDMS substrate. By applying a magnetic field at a specific orientation, the magnetic micromirrors align themselves with the field due to magnetic shape anisotropy. The color spectra of these micromirrors undergo changes, which allows us to detect the tilting angle changes of these micromirrors. This information enables us to deduce the local stiffness of the biomimetic material located on top of the micromirror array. By harnessing the power of OMA, we aim to contribute to the advancement of toolboxes in the mechanobiology field and drive forward our understanding of biological processes.