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SUMMARY:Materials from Colloidal Particles using Optical Fields - Katherin
 e Macmillan (Heinrich-Heine-Universität Düsseldorf )
DTSTART:20190516T154000Z
DTEND:20190516T160000Z
UID:TALK124603@talks.cam.ac.uk
CONTACT:INI IT
DESCRIPTION:Katherine A. Macmillan\, Erick Sarmiento and Stefan U. Egelhaa
 f The interaction of light with colloidal particles has been widely exploi
 ted in optical tweezers [1]. In addition\, multiple traps or extended pote
 ntial energy landscapes (optical fields) have been applied using periodic 
 interference patterns\, speckle patterns created using ground glass and fr
 eely configurable patterns created using spatial light modulators [1\, 2].
  The capability of these optical potential energy landscapes to trap multi
 ple colloidal particles in a designed structure has yet to be fully explor
 ed. In order to pursue this goal\, here we study a two dimensional colloid
 al glass in a periodic potential. We find that a periodic potential with a
  periodicity commensurate with the lattice spacing for a hexagonally close
  packed array can induce the particles to crystallise. We have investigate
 d the influence of parameters describing the potential on the formation of
  crystals from disordered structures. Upon the removal of the periodic pot
 ential\, the colloidal particles can return to a more disordered state ren
 dering the crystal structures only transient. The possibility of fixing th
 is transient state by attaching the particles together has begun to be inv
 estigated. In the future\, we aim to use optically-created potential energ
 y landscapes to imprint a structure on a dispersion of colloidal particles
  that can be fixed by covalently bonding the particles together. [1] Richa
 rd D. L. Hanes\, Matthew C. Jenkins and Stefan U. Egelhaaf\, Review of Sci
 entific Instruments\, 2009\, 80\, 083703  [2] F. Evers\, R.D.L. Hanes\, C.
  Zunke\, R.F. Capellmann\, J. Bewerunge\, C. Dalle-Ferrier\, M.C. Jenkins1
 \, I. Ladadwa\, A. Heuer\, R. Casta&ntilde\;eda-Priego and S.U. Egelhaaf\,
  European Physical Journal Special Topics\, 2012\, 222\, 2995&ndash\;3009
LOCATION:Seminar Room 1\, Newton Institute
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