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Soft and Biomatter Theory


Admission Requirements

No special requirements for those admitted to the MSc programme Research in Physics


In soft matter physics we study physical constituents – particles or complex molecules - whose relevant interactions are small enough (often of order kT) that the matter is easily deformed, hence soft. Many soft matter materials and concepts are relevant for biology. In this course you will get an introduction to the most basic soft matter systems and phases, and to the most important concepts to describe and analyze them. Attention is paid to practical (biological) applications. We aim to pay due attention to general applicability of the techniques and concepts, and to connections with other areas of physics.

We will start the course with an elementary introduction to fluid dynamics, elasticity and fluctuation phenomena like Brownian motion. After this we three important examples of soft matter, colloids, polymers and liquid crystals.

The core of the course is formed by 12 lectures of two hours. For the course we will follow the syllabus which is provided, and which contains essentially all the material covered. Six additional exercise classes will deepen your understanding and train you how to do practical calculations or estimates yourself.

Topics covered:
Basics of fluid mechanics and of elasticity theory
The Reynolds number; small Reynolds number hydrodynamics in biomatter
Brownian motion of particles in a fluid
Use of the fluctuation-dissipation theorem to measure stiffness-constants in biomatter
Introduction to Colloids; forces between colloidal particles; clusters; scattering experiments to probe cluster structure;
Elements of polymers: random walks; ideal chains and force extension of ideal chains; wormlike chain model of biopolymers; behavior of chains in solution;
Elements of liquid crystals
Frank elastic energy of liquid crystals

All students are required to give a presentation about a paper from the (recent) literature for all course participants. A list with suitable papers is provided, but students can also propose a suitable paper themselves.

Course objectives

After completion of the course you will be able to

  • critically discuss the concepts and material treated in the course using a blackboard or whiteboard.

  • explain intermediate steps in a line of reasoning in a research paper in the field.

  • explain intermediate steps in the reasoning leading to a Landau-type coarse grained description of a soft matter or biophysical problem, and use the approach to analyse a problem.

  • perform or critically follow a simple linear stability calculation.

  • critically discuss the scaling behavior of long polymers and the relation to critical phenomena.

Generic skills (soft skills)

After completion of the course you have gained enough background to independently learn about these topics from the specialized literature.


Physics Schedule

Mode of instruction

Lecture and tutorials (6 exercise classes); a syllabus is provided.

Assessment method

The assessment is based on three parts:
1. Participation and performance in the exercise class (pass/fail).
2. Presentation about a relevant research paper (pass/fail)
3. After the course, students will take an oral exam, at a mutually agreeable date in December or January that fits the student's schedule and preferences. The oral exam takes about an hour, and is in the spirit of an informed discussion in front of the blackboard about the course material.

The aim of the oral exam is to test whether you have studied and grasped the material covered in the syllabus. This does not mean, of course, that you need to memorize everything in the syllabus – in fact, you should feel free to take the syllabus or any notes with you to the exam. Think of the exam more as an intelligent discussion about the concepts that were treated in the course. We will use a blackboard or whiteboard, and I might show you some experimental data to discuss these with you in the light of the material that I covered. The exam is in a relaxed atmosphere and we hope that you will actually learn from the oral exam. Professor Schiessel is present at the exam as a second examiner. The final mark for the course is determined by the oral exam.

PhD students who take the course only for pass/fail do not have to do the exercises.


Course material is on Blackboard.
To have access to Blackboard you need a ULCN-account.Blackboard UL

Reading list

The main course material will be covered in a syllabus which the students can obtain at the first lecture. An additional reader with figures and certain additional material is also provided.
Primary text book: Soft Matter Physics – an Introduction by M. Kleman and O. D. Lavrentovich (Springer 2003).
This book contains many more topics than can be covered in the course, and will therefore also be a useful reference guide during your later studies. We will clearly indicate during the course which parts of the book are used and examined. It is not strictly obligatory, though, to buy this book.


Lecturer: [ van Saarloos]