Study on characterization methods of the deformation properties of soft material polydimethylsiloxane using the indentation test

Abstract

Soft materials are widely used in biomedical and flexible electronics fields, while their deformation properties are affected by many factors. It is difficult to obtain accurate characteristic parameters using common test methods. In this work, polydimethylsiloxane is used as the tested object, and the samples with different mass ratios of curing agent/base and thicknesses are prepared. The deformation properties of polydimethylsiloxane under the conditions of different loads and two indenters are investigated using the experiment and finite element analysis, and the factors affecting its deformation properties are discussed. The results demonstrate that the elastic modulus of polydimethylsiloxane is positively correlated with the content of curing agent, and the load has no significant role in its deformation properties. The correlation coefficients between the indentation tests and finite element results are in excess of 0.92. The difference between the modulus of the spherical indentation mode and the elastic modulus of the standard tensile test is lower than 3 %, while the flat‐ended indentation mode is more applicable to characterizing deformation properties of soft materials with variable thickness. These results will provide a new insight into the deformation characterization of soft materials.