Dynamic gap structure for high-throughput measurement of cellular mechanical properties

Precise quantification of cellular mechanical properties, such as Young's modulus, is essential for understanding cellular physiology, disease progression, and therapeutic responses. In contrast to existing deformability cytometry approaches that rely on fixed constrictions, extensional flows, or hydrodynamic shear, we present an all-glass microfluidic platform incorporating a Dynamic Gap Structure (DGS), formed by an 30 μm ultra-thin glass membrane integrated within a rigid microchannel. This design enables high-throughput mechanical characterization of suspended cells under well-defined compressive loading. The DGS allows large populations of cells to pass through a tunable constriction under precisely controlled pressure, accommodating cell-to-cell heterogeneity while exhibiting robust clog resistance. By correlating the applied pressure with the resulting whole-cell deformation during passage through the gap, we estimate the apparent Young's modulus of A549, C6, and NIH3T3 cells. Furthermore, pharmacological perturbation using latrunculin A at different concentrations demonstrates clear, dose-dependent changes in cell stiffness, confirming the platform achieves a minimum resolvable stiffness difference of approximately 0.1-0.2 kPa for cytoskeletal alterations. Compared with atomic force microscopy (AFM), the proposed method offers substantially higher throughput and improved measurement consistency, resulting in narrower modulus distributions. This label-free platform enables robust mechanical phenotyping of cells and shows potential for applications in cancer diagnostics, drug screening, and mechanobiology. However, the present study is limited to proof-of-concept validation using model cell lines, and extension to primary or clinical samples requires further investigation.