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A novel method to determine the elastic modulus of extremely soft materials

Stirling, Tamás

Zrínyi, Miklós

2015

QD02 Physical chemistry / fizikai kémia

Determination of the elastic moduli of extremely soft materials that may deform under their own weight
is a rather difficult experimental task. A new method has been elaborated by means of which the elastic
modulus of such materials can be determined. This method is generally applicable to all soft materials
with purely neo-Hookean elastic deformation behaviour with elastic moduli lower than 1 kPa. Our novel
method utilises the self-deformation of pendent gel cylinders under gravity. When suspended, the
material at the very top bears the weight of the entire gel cylinder, but that at the bottom carries no
load at all. Due to the non-uniform stress distribution along the gel sample both the stress and the
resulting strain show position dependence. The cross-sectional area of the material is lowest at the top
of the sample and gradually increases towards its bottom. The equilibrium geometry of the pendant gel
is used to evaluate the elastic modulus. Experimental data obtained by the proposed new method were
compared to the results obtained from underwater measurements. The parameters affecting the
measurement uncertainty were studied by a Pareto analysis of a series of adaptive Monte Carlo
simulations. It has been shown that our method provides an easily achievable method to provide an
accurate determination of the elastic modulus of extremely soft matter typically applicable for moduli
below 1 kPa.

Article

PeerReviewed

text

http://real.mtak.hu/33151/2/extremely_soft_gels_cikk.pdf

Stirling, Tamás and Zrínyi, Miklós (2015) A novel method to determine the elastic modulus of extremely soft materials. Soft Matter. pp. 4180-4188. ISSN 1744-683X

http://dx.doi.org/10.1039/c4sm02325k

http://real.mtak.hu/33151/