Professor Alfredo Alexander-Katz, MIT.  "Adaptive Soft Matter:  From Mechanisms to Function." Woodward CCB Departmental ColloquiumAbstract:  Soft matter belongs to a class of materials that are held by weak interactions. Most of the biological world is made of soft materials, such as biopolymers and proteins, which are used to perform a multitude of functions. Here I will present our work on adaptive soft matter that responds readily to external stimuli and can adapt and navigate in different environments. In particular I will touch on two different systems that respond to different stimuli: inhomogeneous flowing conditions and hydrophilic/hydrophobic interfaces, two common scenarios in our body.  In the later case I will introduce a new class of nanoparticles with an interface that can adapt to inhomogeneous chemical conditions by reshaping its surface chemical properties. This allows such nanoparticles to fuse with cell membranes and cross into internal compartments in the cell. In the case of flow and inspired in the problem of blood clotting I will discuss how nature has engineered flow responsive macromolecules that can rapidly change their bonding state from inert to multivalent and induce clotting at sites of injury in the blood vessel system. I will conclude with a perspective on how looking into such fundamental problems has provided new knowledge to understand other unrelated topics as well as brought new questions into light.