The invention is a microfluidic device that can measure compressive stresses on blood stem and progenitor cells and assess their functional capacity. The device can be used to improve protocols for expanding blood stem cells outside of the body. It is also adaptable for use with other non-adherent cells. The device captures and immobilizes a heterogeneous cell population, applies mechanical stress through shear rate and controlled compression, and allows for downstream biological assays. The impact of the mechanical stimulus is observed through microscopy, and the cells can be retrieved for further analysis.