(618d) Biaxial Mechanics of Biocomposite Thin Films Supported On Polydimetylsiloxane (PDMS)

We discuss biaxial mechanical measurements of force-displacement and digital image correlation for lamellar composites of biocomposite thin films supported by PDMS.  Biofilms of the E. Coli mutant d21g were growth on 5x5 mm PDMS substrates under different environmental conditions and age.  We show that by modulating the cross-link density of PDMS, the biolfilm elasticity can be estimated from the force-displacement data.  Additionally, by measured the strain field of the composite system, the relative important of interlayer adhesion can also be determined.  In the systems we studied, adhesive interactions between PDMS and d21g play a larger role in the displacement of individual bacteria in the biofilm under tension.