"Active Dynamics on Microscales: Molecular Motors and Self-Propelled Particles"

17 21 September 2012


Single-molecule protein motors play a fundamental role in biological cells and are responsible for a variety of functions, including force generation in muscles and intracellular transport. Similar to macroscopic machines, their operation involves cyclic internal conformational motions which are transformed into steady translational or rotational movements of the motor through ratchet effects. Energy supply is essential here and nonequilibrium active dynamics at the molecular level is characteristic for such systems. In contrast to macroscopic machines, protein motors need, however, to work in the presence of strong thermal fluctuations and high noise. Hence, robustness of ordered internal motions becomes a primary requirement. On the other hand, nanoscale devices may also actively exploit fluctuations, making them contribute towards the motor function.


Although cell motility has long been studied by biologists, major advances in developing mechanistic descriptions have been made in the past few years. Applications of dynamical systems theory and new experimental methods have led to detailed propulsion mechanisms in terms of molecular machines. We now know, for example, that an intricate synchronization of hundreds of flagella forms the propulsion mechanism for certain algae, and that collective motions of swarming bacteria can lower the effective viscosity of the host fluid. Recently, nonbiological micro- to nano-scale particles have been investigated that convert chemical energy into translational motion. These systems provide an opportunity to explore mechanisms of chemomechanical energy transduction and offer a link to self-propelled particles in living systems.


The workshop has brought together leading experts from a wide range of research areas, with studies of molecular to micro-scale motors forming the common thread. Experimental and theoretical research on biological and nonbiological systems has been presented and discussed, bringing new investigative tools and analyses to the participants. The topics covered in the workshop were wide-ranging yet interconnected.  Formal and informal discussions between the participants yielded new mechanistic insights and new investigative tools have been proposed, contributing to the workshop's success. The workshop benefited from the topical mix of biological and nonbiological systems and both theoretical and experimental points of view. A major goal of the workshop was to stimulate discussions between participants specializing in different aspects of molecular motors and self-propelling particles and this goal has been successfully implemented.


This workshop was organized together with the Berlin Center for Studies of Complex Chemical Systems.

Scientific Organizers:

Arjen Doelman (Leiden, Netherlands)
Alexander Mikhailov (Berlin, Germany)
Kenneth Showalter (Morgantown, USA)