Abstract

Stochastic processes play a key role in the communications inside the cells, cell mitosis and membrane channel regulation. It has been suggested that the molecular transport mechanism can be based on rectified thermal diffusion in a Brownian ratchet. A two-dimensional optical potential of circular symmetry created by a Bessel light beam is an ideal playground to study these phenomena. This optical field can be tilted to create a periodic (washboard) potential of imperfect Brownian ratchet. The tilt variation induces a directed transport of microparticles or biomolecules across the potential barriers when biomolecules attached non-covalently to these microparticles. In the central maximum of Bessel beam particles can be guided due to radiation pressure. Our data offer a new venue for understanding of cooperative phenomena in biology.

© 2003 SPIE