Trapping and Ultrafast Rotation of Resonant Nanoparticles using Optical Tweezers

Trapping and Ultrafast Rotation of Resonant Nanoparticles using Optical Tweezers

Hosted By: Optical Trapping and Manipulation in Molecular and Cellular Biology Technical Group

12 September 2019, 11:00 AM - 12:00 PM

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Optical resonances in nanoparticles enhance light-matter interactions can be utilized to amplify optical forces at the nanoscale. In this webinar, Prof. Mikael Kall will discuss recent optical trapping studies of gold and silicon nanoparticles, exhibiting localized plasmon and Mie resonances, respectively, and outline how the resonance effects influence trapping behavior and thermal forces. The presenter will describe how one can use photonic torques to force colloidal nanoparticles to rotate at kHz frequencies in optical tweezers and how the rotary nanomotors are used to probe and influence their local environment. For instance, it is possible to estimate the viscosity of the surrounding liquid, to precisely measure changes in the thickness of molecular layers covering the particles, and to release DNA from the particles through controlled photothermal heating.

What You Will Learn:

  • Concept of optical tweezers
  • How optical tweezers can be applied for the trapping and ultrafast rotation of resonant particles to serve as nanomotors
  • How rotary nanomotors can be used to probe and influence their local environment 

Who Should Attend:

  • Physicists
  • Biologists
  • Chemists
  • Engineers


About the presenter(s):

Mikael Kall, Chalmers University of Technology

Mikael Käll is a professor of physics and head of the bionanophotonics group at the Department of Physics, Chalmers University of Technology. After receiving a PhD on spectroscopy of high-Tc superconductors at Chalmers in 1995, he spent a post doc year on diffraction analysis of cuprates at Risø National Laboratory, Denmark. He then moved back to Chalmers, where he has been full professor since 2006. Since the end of the 1990’s, his main body of work concerns nanophotonics, in particular plasmonics, where he has contributed to a large number of influential publications on various topics of fundamental and applied research. His current research interests include light-induced forces on nanoparticles and the application of resonant nanoparticles and metasurfaces in biomolecular sensing and actuation.