Guiding and trapping microparticles in an extended surface field

Y. Garcés-Chávez, G. C. Spalding, K. Dholakia

Research output: Contribution to journalConference articlepeer-review

2 Citations (Scopus)


We made use of near-field photonic forces in order to manipulate and trap microparticles in an extended area above a solid surface. Structures in evanescent field were created either by imaging a Ronchi ruler (fringe structure) or by focusing five beams (spot structure) at the top of a prism. The surface field couples to microparticles in close proximity, where the near-field wave can be converted to a propagating wave, via photon tunnelling across the gap from prism to microparticles. Due to transverse optical gradients and radiation pressure, microparticles immersed in water were laterally trapped and longitudinally guided along the direction of the evanescent waves. By splitting the laser beam into two equal counterpropagating beams, another evanescent wave was created exactly with the same structure in the opposite direction to the first one. We use this geometry we demonstrate stably trap of thousand of microparticles over an area of about a millimetre squared. Red blood and yeast cells were also individually trapped in an array of potential wells. We believe this is the first demonstration of guiding and, separately, trapped in unison multiple microparticles on a surface.

Original languageEnglish
Article number78
Pages (from-to)569-577
Number of pages9
JournalProceedings of SPIE - The International Society for Optical Engineering
Publication statusPublished - 2004
EventOptical Trapping and Optical Micromanipulation - Denver, CO, United States
Duration: 2004 Aug 22004 Aug 6

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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