Soft Materials Laboratory

We are part of the Institute of Materials (IMX) at EPFL. We introduce polymer-based granular materials that combine stiffness, toughness and fatigue resistance. To achieve this goal, we load deformable polymeric microparticles with reagents before transforming them into extrudable pastes that can be 3D printed and solidified on demand. This approach enables the formation of load-bearing, tough, and fatigue-resistant double-network granular materials whose composition can be controllably changed in all three dimensions on length scales of order 100 µm. This is achieved through energy-efficient and environmentally friendly processes. We investigate how processing conditions, microstructure, and local composition influence the mechanical properties and functionality of these materials. We leverage the granular structure to introduce functionalities, including piezoresistivity and electrical conductivity, into them. These materials can be used, for example, as efficient dampers with rapid shape recovery, soft yet highly sensitive strain sensors, actuators, and, if mineralized, we envisage them to be promising scaffolds to aid bone repair.