Linear and nonlinear laser-trapping microrheology


Conference Paper

We have developed a high-bandwidth technique for active 2-particle microrheology (AMR) with which we can probe linear and nonlinear responses of soft materials. Micron-sized colloidal probe particles are driven by an oscillating optical trap, and the resulting correlated motions of neighboring particles are detected by laser interferometry. Lock-in detection at the driving frequency and at its second harmonic makes it possible to measure the linear and the non-linear response of the embedding medium at the same time. We demonstrate the sensitivity of the method by detecting a second-harmonic response in water which is of purely geometric origin and which can be fully understood within linear hydrodynamics.

Full Text

Duke Authors

Cited Authors

  • Schmidt, CF; Mizuno, D

Published Date

  • December 1, 2007

Published In

Volume / Issue

  • 6644 /

International Standard Serial Number (ISSN)

  • 0277-786X

International Standard Book Number 13 (ISBN-13)

  • 9780819467928

Digital Object Identifier (DOI)

  • 10.1117/12.739441

Citation Source

  • Scopus