Micro-fracture development in visco-elastic material through fluid fracturing

Hydraulic fracturing of rocks is a frequently practiced technique in upstream hydrocarbon industry. However, the phenomena relates to brittle fracture. Fracture formation in visco-elastic materials is a relatively poorly understood process. Inspired by hydraulic fracturing of rocks, fluid fracturing of viscoelastic materials is the proposed technique for the development of micro fractures or pores in a viscoelastic material which is not only simple but effective too. In this method fluid is injected inside the material and at sufficient pressure fractures are observed. In our research, we have found that this method can be used to develop micro fractures of controlled morphology, size and orientation, and thus can have vital applications. Micro fracture development can find a wide range of application including micro filtration, microfluidics, micro reactors, adsorption etc. This paper discusses the basic methodology and the results of experiments conducted on cross-linked polydimethylsiloxane (PDMS), mainly focussing upon the morphology and size variation of fracture depending upon the degree of cross linking and fluid injection pressure.