Utilizing Brownian motion for nanoparticle transport and separation
Active transport of nano-sized objects in water faces the challenge of a highly diffusive environment in which the object’s momentum is irrelevant. Nature solves this challenge by using molecular motors, which are complex molecular machines that exploit the Brownian noise input from the environment for an energy efficient transport. Their basic working principle relies on an asymmetric energy landscape and a non-equilibrium energy input to power the motor. Artificial motors, so called “Brownian motors”, that use similar principles were theoretically and experimentally studied since the 1990s. Recently, we implemented rocking Brownian motors for nanoparticles by exploiting the interaction energy between like charged particles and patterned walls in a nanofluidic system to generate the asymmetric energy landscape. The system is driven by a zero-mean electroosmotic force generated by an AC electric field. I will discuss how we can fully characterize this physical system with sub ms temporal and 10 nm spatial resolution by pure optical observation of the Brownian motion of the particles in the driven and the non-driven case. Moreover, we use the nanofluidic system to separate particles according to their size with a resolution of approximately 1 nm in radius. In combination with the active transport the system opens up exciting possibilities, e.g. for a fast detection of ultralow virus concentrations in lab-on-chip devices.
Biography Armin Knoll
Armin Knoll is physicist and received the Ph.D. for studying the phase behavior of cylinder forming block copolymers at the University of Bayreuth, Germany, in 2004. After a postdoctoral fellowship on two-photon lithography with the University of Basel for 15 months (2003-2004) he joined the Millipede project on data storage using heatable scanning probes at the IBM Zurich Research Laboratory. Armin Knoll joined the Science & Technology department in April 2006 as research staff member. Since 2010 he is leading the nanofabrication effort and developed thermal Scanning Probe Lithography to technical market readiness. In 2012 he received an ERC Starting Grant from the European Commission and he is since then leading a project on the control and manipulation of objects in nanofluidic confinement.
Day: Wednesday December 11th
Where: Manufacturing & Engineering
Time: 11:20h – 11:50h