We introduce laser cavitation rheology (LCR) as a minimally-invasive optical method to characterize mechanical properties within the interior of biological and synthetic aqueous soft materials at high strain-rates. We utilized time-resolved photography to measure cavitation bubble dynamics generated by the delivery of focused 500 ps duration laser radiation at λ = 532 nm within fibrin hydrogels at pulse energies of E p = 12, 18 µJ and within polyethylene glycol (600) diacrylate (PEG (600) DA) hydrogels at E p = 2, 5, 12 µJ. Elastic moduli and failure strains of fibrin and PEG (600) DA hydrogels were calculated from these measurements by determining parameter values which provide the best fit of the measured data to a theoretical model of cavitation bubble dynamics in a Neo-Hookean viscoelastic medium subject to material failure. We demonstrate the use of this method to retrieve the local, interior elastic modulus of these hydrogels and both the radial and circumferential failure strains.
We demonstrate an interferometric method to provide direct, single-shot
measurements of cavitation bubble dynamics with nanoscale spatial and
temporal resolution with results that closely match theoretical
predictions. Implementation of this method reduces the need for
expensive and complex ultra-high speed camera systems for the
measurement of single cavitation events. This method can capture
dynamics over large time intervals with sub-nanosecond temporal
resolution and spatial precision surpassing the optical diffraction
limit. We expect this method to have broad utility for examination of
cavitation bubble dynamics, as well as for metrology applications such
as optorheological materials characterization. This method provides an
accurate approach for precise measurement of cavitation bubble
dynamics suitable for metrology applications such as optorheological
materials characterization.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.