Jam it all in there: an active material made from packed microgels, a protein network, and contractile cells

The living soft tissue cell can modulate its own elasticity, contractilty, orientation, migration speed, and shape in response to physical stimuli such as externally applied forces or varying stiffness of its surroundings. Thus, as we work toward developing and understanding autonomously adaptive materials, we take inspiration from the soft tissue cell, which represents a canonical example of self-modulated adaptation. In this talk I will show how to combine the reconfigurability of microgels with the non-linear elasticity of biopolymer networks and the activity of highgly contractile tissue cells to create a 3D printable material that, as a whole, exhibits a variety of cell-like behaviors. For example, the small-amplitude oscillatory rheological response of these materials is consistent with the soft glassy behaviors found with the cytoskeleton of living cells. Likewise, we can map externally applied strain stiffening behaviors onto those generated internally by contractile cells, in analogy to how molecular motors strain-stiffen the cytoskeleton. Finally, structures made from this biocomposite materials spontaneously migrate on surfaces, leading us to name them "supercells." We will discuss the structural analogy between single tissue cells and the "supercell," drawing parallels between the key physical components of each.