An acoustic squeezer for assessment of multiparameter cell mechanical properties

Cells' ability to sense and respond to mechanical stimuli is fundamental to various biological processes and serves as a crucial biomarker of their physiological and pathological states. Traditional methods for assessing cell mechanical properties, such as atomic force microscopy and micropipette aspiration, are hindered by complex procedures and the risk of cellular damage due to direct contact. Here we introduce a novel non-contact acoustic squeezer that leverages focused interdigital transducers to induce cell deformation through a robust standing surface acoustic wave (SSAW) field. This approach enables the multiparametric quantification of multiple mechanical properties, including elasticity (Young's modulus, stiffness) and viscosity, without requiring labeling or physical contact, providing a comprehensive understanding of the cell mechanical properties. Our acoustic squeezer is capable of generating a maximum squeezing force of 25.70 pN, inducing a deformability of 1.27 ± 0.017. Combined with thin-shell deformation model, the quantized Young's modulus of normal red blood cells (RBCs) is approximately 919.04 ± 55.64 Pa. Furthermore, our method demonstrates that cells treated with the anti-cancer drug (doxorubicin) exhibited reduced deformability, increased Young's modulus and viscosity. Our acoustic squeezer offers a standardized, non-invasive, and highly sensitive approach for characterizing cell mechanical properties, with significant promise for clinical applications in disease diagnosis and drug development.