Journal of Nanoparticle Research

, Volume 1, Issue 4, pp 495–499

A New Probe for Mechanical Testing of Nanostructures in Soft Materials

  • L.A. Hough
  • H.D. Ou-Yang

DOI: 10.1023/A:1010075223642

Cite this article as:
Hough, L. & Ou-Yang, H. Journal of Nanoparticle Research (1999) 1: 495. doi:10.1023/A:1010075223642


We report a new application of the optical tweezers, where a harmonically driven oscillating tweezer is combined with the forward light scattering and lock-in amplification techniques, for probing the mechanics of nanostructures in soft materials in a broad frequency range. Model independent dynamic moduli G′ and G″ of the material at a localized, sub-micron area can be measured directly from the displacement and the phase shift of the particle in the oscillating trap. The probe particles can be as small as 200 nm and the displacement of the particle was in the range of a few nanometers. To illustrate the new methodology, we show the microscopic viscoelastic properties of a transient polymer network in the vicinity of a silica bead.

optical tweezers nanoparticles particle-medium interaction dynamic mechanical testing dynamic moduli viscoelasticity 

Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • L.A. Hough
    • 1
  • H.D. Ou-Yang
    • 1
  1. 1.Physics DepartmentLehigh UniversityBethlehemUSA

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