Journal article

Differential dynamic microscopy microrheology of soft materials: A tracking-free determination of the frequency-dependent loss and storage moduli

  • Edera, Paolo Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Universit? degli Studi di Milano, Segrate (MI) I, Italy
  • Bergamini, Davide Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Universit? degli Studi di Milano, Segrate (MI) I, Italy
  • Trappe, Véronique Department of Physics, University of Fribourg, Switzerland
  • Giavazzi, Fabio Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Universit? degli Studi di Milano, Segrate (MI) I, Italy
  • Cerbino, Roberto Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Universit? degli Studi di Milano, Segrate (MI) I, Italy
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    29.12.2017
Published in:
  • Physical Review Materials. - 2017, vol. 1, no. 7, p. 073804
English Particle-tracking microrheology (PT-μr) exploits the thermal motion of embedded particles to probe the local mechanical properties of soft materials. Despite its appealing conceptual simplicity, PT-μr requires calibration procedures and operating assumptions that constitute a practical barrier to its wider application. Here we demonstrate differential dynamic microscopy microrheology (DDM-μr), a tracking-free approach based on the multiscale, temporal correlation study of the image intensity fluctuations that are observed in microscopy experiments as a consequence of the translational and rotational motion of the tracers. We show that the mechanical moduli of an arbitrary sample are determined correctly over a wide frequency range provided that the standard DDM analysis is reinforced with an iterative, self-consistent procedure that fully exploits the multiscale information made available by DDM. Our approach to DDM-μr does not require any prior calibration, is in agreement with both traditional rheology and diffusing wave spectroscopy microrheology, and works in conditions where PT-μr fails, providing thus an operationally simple, calibration-free probe of soft materials.
Faculty
Faculté des sciences et de médecine
Department
Département de Physique
Language
  • English
Classification
Physics
License
License undefined
Identifiers
Persistent URL
https://folia.unifr.ch/unifr/documents/306266
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