Dresden 2017 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 36: Brownian Motion (jointly with DY)
TT 36.10: Vortrag
Dienstag, 21. März 2017, 12:30–12:45, ZEU 147
Particle transport using rocking Brownian motors — •Christian Schwemmer1, Stefan Fringes1,2, Colin Rawlings1, and Armin Knoll1 — 1IBM Research - Zurich, Switzerland — 2Institute of Physical Chemistry, University of Zurich, Switzerland
Inspired by how intracellular transport is achieved in nature [1], artificial Brownian motors have been designed to allow for particle transport in fluids [2].
The two main requirements are a spatially asymmetric potential and an external driving force. For our implementation, we utilize a novel approach to transport 60 nm gold particles inside a nanofluidic slit. In detail, we use the electrostatic interaction between the gold particles and surfaces to define, similar to geometry induced trapping [4], a potential landscape. Therefore, one of the confining surfaces is patterned with a 3D ratchet topography by thermal scanning probe lithography [3] which then directly translates to a potential landscape.
In contrast to most previous experiments which used flashing ratchets, we realized a rocking ratchet
by applying a zero-mean AC electric field across the slit delivering high particle drift speeds of up to 100 µm/s. Experimentally, we could further show that the potential landscape and thus the transport properties strongly depend on the particle size and the gap distance of the slit. By exploiting this property, we plan to develop a fast and highly selective nanoparticle sorting device.
[1] Vale et al., Science, 288, 88, (2000)
Hänggi et al., Rev. Mod. Phys, 81, 387, (2009)
Pires et al., Science, 328, 732, (2010)
Krishnan et al., Nature, 467, 692, (2010)