Stochastic optical active rheology
AUTHORS
Lee
H. ,
Shin
Y. ,
Kim
S.T. ,
Reinherz
E.L. ,
Lang
M.J. .
Applied Physics Letters. 2012 ; 101(3).
031902
- PMID: 22893729[PubMed].
- PMCID: PMC3411558.
ABSTRACT
We demonstrate a stochastic based method for performing active rheology using optical tweezers. By monitoring the displacement of an embedded particle in response to stochastic optical forces, a rapid estimate of the frequency dependent shear moduli of a sample is achieved in the range of 10−1–103 Hz. We utilize the method to probe linear viscoelastic properties of hydrogels at varied cross-linker concentrations. Combined with fluorescence imaging, our method demonstrates non-linear changes of bond strength between T cellreceptors and an antigenic peptide due to force-induced cell activation.