Ruprecht Karls Universität Heidelberg

Theory of soft and biomatter

In the summer term 2005, I will teach a course on Theory of soft and biomatter (Thursday 2.15-3.45 pm, OMZ R U014, INF 350, first lecture April 21st). This course provides an introduction to the theoretical concepts used to describe the equilibrium properties of soft matter. Soft matter is condensed matter which is characterized by energy scales close to thermal energy and length scales larger than atomic length scales. Then a small elastic modulus results and thermal noise is sufficient to induce structural changes. This outstanding property of soft matter systems allows them to self-organize and to self-heal. Soft matter includes material systems like colloidal suspensions, liquid crystals, fluid-fluid interfaces, fluid membranes and polymers. It also includes biomatter, like the lipid bilayer and the filamentous proteins of the cytoskeleton. We will start by discussing important molecular and colloidal interactions. We then will turn to the statistical mechanics of simple and complex fluids which results from these interactions, in particular phase behaviour. Next we deal with low-dimensional objects (strings and surfaces), which determine the properties of many soft matter systems. In particular, we deal with interfaces, membranes and polymers. We finally introduce the basic concepts from elasticity theory and hydrodynamics, which often are important in soft matter and biological physics. If time permits, we might also address some dynamical issues. Throughout the whole course, applications to biological systems will be emphasized. Moreover, the first and last lectures directly address biological issues. This course is in English and addresses students after the Vordiplom from physics and related disciplines.

Recommended literature

  • SA Safran, Statistical thermodynamics of surfaces, interfaces, and membranes, Addison-Wesley, Reading 1994
  • PM Chaikin and TC Lubensky, Principles of condensed matter physics, Cambridge University Press, Cambridge 1995
  • JN Israelachvili, Intermolecular and surface force, 2nd edition, Academic Press 1991
  • DF Evans and H Wennerstr�m, The colloidal domain: where physics, chemistry, and biology meet, 2nd edition, Wiley 1998
  • RAL Jones, Soft condensed matter, Oxford University Press 2002
  • KA Dill and S Bromberg, Molecular driving forces : statistical thermodynamics in chemistry and biology, Garland Sci. 2003
  • R Lipowsky and E Sackmann, Eds., Structure and Dynamics of Membranes, Elsevier, Amsterdam 1995
  • LD Landau and EM Lifschitz, Elasticity Theory (VII), Butterworth-Heinemann, Oxford


  1. 21.4.: Introduction: soft matter & biological physics, membranes & polymers in cells, shape of vesicles, capsules & cells, basic scales in cellular systems
  2. 28.4. + 12.5. + 19.5.: Molecular and colloidal interactions: electrostatic interaction, Poisson-Boltzmann theory, strong coupling limit, Debye-Hueckel theory, dipolar interactions, van der Waals interaction, Hamaker theory, Derjaguin approximation, hydrophilic/hydrophobic interactions, depletion interaction, DLVO theory
  3. 2.6. and 9.6.: Simple and complex fluids: ideal gas, virial expansion, van der Waals fluid, hard spheres, liquid crystals, isotropic-nematic transition, Gibbs phase rule, amphiphilic systems
  4. 16.6. and 23.6.: Fluid-fluid interfaces: Ginzburg-Landau theory, kink solution, surface tension, introduction to differential geometry, capillary waves, Laplace equation, wetting, Young equation, foams, Rayleigh-Plateau instability, software surface evolver
  5. 30.6.: Fluid membranes: curvature energy, fluctuations, Helfrich interaction, vesicle shapes, vesicle adhesion
  6. 7.7.: Elasticity theory: stress and strain, Hookean body and Newtonian fluid, isotropic material, contact mechanics, JKR-theory, shell theory, cell mechanics

Last modified Fr Jun 24 10:25:34 CEST 2005 by USS.

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