ABSTRACT
Soft condensed matter physics is concerned with the study of complex uids: liquids in which there is an intermediate, or mesoscopic, length scale between the atomic (∼ 0.1− 1 nm) and the macroscopic (∼ 1 mm or more). It became a recognisable, separate branch of physics relatively recently (Poon and Warren 2001). The key idea in modern soft condensed matter physics is that complex uids possess features that are independent of chemical details. All colloids undergo Brownian motion. Polymers of all kinds share features arising out of intramolecular connectivity. Aspects of the self-assembly of any surfactant (or surface-active molecule) can be understood by treating it as a truncated cone of suitable shape. (For detailed introductions to soft condensed matter physics, see the chapters by Frenkel, Warren and Olmsted in this volume.)
Biology is ‘soft matter come alive’. DNA, RNA and proteins are essentially random1 polymers (for DNA as polymer, see the chapters by Warren and Bensimon in this volume). The lipids that make up various biological membranes are surfactants (see the chapter by Olmsted in this volume), and the membranes themselves can be viewed as soft elastic sheets (see the chapter by Kozlov in this volume). Vesicles, inclusion bodies and even globular proteins can be viewed as colloids. At rst sight, therefore, nothing can be more obvious than the claim, embodied in the title of this school, that soft condensed matter physics should nd extensive application in biology. But matters are not so straightforward.
