Optical trapping of a spherically symmetric rayleigh sphere: A model for optical tweezers upon cells

Yi-Ren Chang, Long Hsu, Sien Chi

Research output: Contribution to journalArticle

20 Citations (Scopus)


Optical tweezers have become a popular manipulation and force measurement tool in cellular and molecular biology. However, there is still a lack of a sophisticated model for optical tweezers on trapping cells. In this paper, we present a novel model for optical tweezers to calculate the stiffness of trapping force upon a spherically symmetric Rayleigh sphere, which stimulates a common biological cell. A numerical simulation of this model shows that the stiffness of an optical tweezers system in trapping a cell is significantly smaller than that in trapping a polystyrene bead of the same size. Furthermore, under a small variant condition of the refractive index, the proposed model provides an approximate method which requires only the radial distribution of the trapped cell's refractive index for calculating the stiffness.

Original languageEnglish
Pages (from-to)97-105
Number of pages9
JournalOptics Communications
Issue number1-3
Publication statusPublished - 2005 Feb 1



  • Biophotonics
  • Optical tweezers
  • Rayleigh scattering

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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