Rigidity and Resilience of Active Composite Networks: Bridging Biology and Biomimetic Design

Living cells and tissues exhibit remarkable emergent properties, such as mechanical rigidity, resilience, and adaptability in response to stimuli. These mechanical responses arise from the collective behavior of their cytoskeleton—a dynamic scaffold composed of biopolymers, crosslinking proteins, and motor proteins—and its interactions with the extracellular matrix. In this talk, I will address key questions about active composite biopolymer networks in cells and tissues, as well as the rational design of biomimetic soft materials: What are the underlying physical principles that enable cells and tissues to be soft and mechanically tunable, while remaining resilient and damage-resistant? Can we engineer composite soft materials to replicate such life-like emergent properties? And, is it possible to activate synthetic soft materials with these properties using biological processes? I will begin by exploring the physical mechanisms behind the soft yet resilient mechanical properties of biopolymer networks in cells and tissues. Using rigidity percolation theory, I will demonstrate how the interplay between composite and heterogeneous composition and activity shapes the mechanics of these biological materials and suggest design principles for artificial constructs. I will then discuss how functionalized clock proteins—regulators of biological clocks—can be used to engineer self-assembling and disassembling soft material networks with robust kinetics and tunable properties. By leveraging these protein-based reaction networks, we can develop biomimetic materials that not only mimic the rigidity and resilience of living systems but also enable precise control over their physical and functional characteristics, opening new avenues for innovative soft material design.