Stem cell therapy is developing rapidly, but existing expansion techniques are insufficient for the use of a large number of cells. The surface chemistry and surface morphology characteristics of materials play a critical role in cellular behaviors and functions and have guiding significance for the design of biomaterials. Many studies have proven that these factors are essential to affect cell adhesion and growth. How to design a suitable biomaterial interface is the focus of recent studies. Here, the mechanosensing of human adipose-derived stem cells (hASC) on a set of materials and materials with various porosity is systematically studied. Guided by the mechanism discoveries, three-dimensional (3D) microparticles with optimized hydrophilicity and morphology are designed via liquid–liquid phase separation technology. The microparticles support scalable stem cell culture and extracellular matrix (ECM) collection, exhibiting great potential for stem cell applications.