Flexible micropillar array tests mechanical signal transduction in human stem cells on nanoscale

Between fluid shear, tensile forces, and stiffness of the surrounding extracellular matrix, a cell’s microenvironment is replete with mechanical signals that influence a wide range of cellular activities. The intrinsic mechanisms for how these signals influence cell behavior, however, remain incompletely understood. New work on devices that detect nanoscale mechanical compression, called micropillar arrays, looks to shed light on these processes.

Feng et al. have developed a flexible micropillar array device that investigates the mechanical properties of human bone marrow mesenchymal stem cells. Combining micropillar deflection analysis, atomic force microscopy, and immunofluorescence staining, they establish a new relationship between cell morphology, stiffness, and adhesion force. The group explored how microtopographical parameters influence cytoskeletal organization, focal adhesion formation, and other cellular mechanics.

“The innovative aspect of this work lies in the development of a flexible micropillar array that simultaneously functions as a cell adhesion force sensor and a microtopographical regulator,” said author Yanyan Wang. “Unlike conventional systems that separately study topography-induced behaviors and force measurements, this integrated platform enables real-time quantification of cell adhesion forces while modulating cellular morphology and mechanics through controlled micropillar density.”

Prior studies primarily focused either on measuring cellular adhesion forces or investigating how substrate topography affects cell morphology and behavior.

The group found cell adhesion was stronger in low-density arrays and predominantly localized around the nucleus, as opposed to around sticky, finger-like projections used in cell locomotion, called pseudopods. The lower-density arrays also facilitated an increase in pseudopods, making for stronger and stiffer adhesions compared to more densely packed arrays.

The group next looks to develop tools that mechanically measure the spatial dynamics of organoids.

Source: “Cellular behavior regulation and adhesion force measurement based on flexible micropillar arrays,” by Ruoyu Feng, Hang Qi, Xuexin Duan, and Yanyan Wang, Nanotechnology and Precision Engineering (2025). The article can be accessed at https://doi.org/10.1063/5.0270649 .