In:
Scientific Reports, Springer Science and Business Media LLC, Vol. 6, No. 1 ( 2016-12-01)
Abstract:
Natural and synthetic hydrogel scaffolds exhibit distinct viscoelastic properties at various length scales and deformation rates. Laser Speckle Rheology (LSR) offers a novel, non-contact optical approach for evaluating the frequency-dependent viscoelastic properties of hydrogels. In LSR, a coherent laser beam illuminates the specimen and a high-speed camera acquires the time-varying speckle images. Cross-correlation analysis of frames returns the speckle intensity autocorrelation function, g 2 ( t ), from which the frequency-dependent viscoelastic modulus, G* ( ω ), is deduced. Here, we establish the capability of LSR for evaluating the viscoelastic properties of hydrogels over a large range of moduli, using conventional mechanical rheometry and atomic force microscopy (AFM)-based indentation as reference-standards. Results demonstrate a strong correlation between |G* ( ω ) | values measured by LSR and mechanical rheometry ( r = 0.95, p 〈 10 −9 ), and z-test analysis reports that moduli values measured by the two methods are identical (p 〉 0.08) over a large range (47 Pa – 36 kPa). In addition, |G* ( ω ) | values measured by LSR correlate well with indentation moduli, E , reported by AFM ( r = 0.92, p 〈 10 −7 ). Further, spatially-resolved moduli measurements in micro-patterned substrates demonstrate that LSR combines the strengths of conventional rheology and micro-indentation in assessing hydrogel viscoelastic properties at multiple frequencies and small length-scales.
Type of Medium:
Online Resource
ISSN:
2045-2322
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2016
detail.hit.zdb_id:
2615211-3
