Filler-polymer interactions dictate tissue-like compression stiffening in composite hydrogels

Mammalian tissues such as adipose, brain, and liver exhibit stiffening in their shear moduli with increasing compressive normal strain. Though this compression stiffening property has been associated with a composite structure consisting of fibrous polymers and volume-conserving fillers, a detailed understanding of the underlying mechanisms remains missing. In this talk, we demonstrate the crucial role of filler-polymer interactions in dictating the extent of compression stiffening in composite hydrogels, and elucidate the molecular origins of this effect. Our findings suggest a significant role of cell-matrix interactions on the mechanical properties of tissues, and provide a guideline for controlling tissue-mimetic compression stiffening in engineered materials.