Shelby Hutchens (University of Illinois Urbana Champain, USA)
Squishy Stories : Plant-like “Growing” Solids and Soft Solid Cutting
This talk will overview two areas of ongoing work, a plant-tissue inspired soft-active composite and the failure of elastomers and gels during steady-state cutting. Even without the aid of muscle, plant tissue produces large, forceful motion via osmosis-driven fluid flow. The closed-cell structure of plant tissue facilitates high forces via the ability to support turgor pressure, in contrast to typical swelling soft solids, such as hydrogels. We have demonstrated a synthetic, plant tissue analog (PTA) that mimics this structure and performance. Our current interest is understanding the characteristics that govern the physico-chemo-mechanical response timescale. Toward this end, I will present results on deformation-dependent permeability of silicone. Second, fracture in soft, elastomeric solids continues to be an area of inquiry due in part to the challenges of combining large, nonlinear material responses with accumulation of damage at and near the crack surface via a microstructural description. As a result, even commonly encountered failure geometries such as cutting (driven by blade insertion), needle insertion, and tearing (initiated by force far from the crack tip) are not quantitatively related to one another. Our previous Y-shaped silicone cutting data provided a promising qualitative and quantitative linkage between far-field tearing and push cutting. The control facilitated by this technique further enables tunable crack surface morphologies, which we have begun to quantitatively characterize with the aim of better understanding frictional effects during needle insertion.
Short bio :
Shelby Hutchens is an Associate Professor at University of Illinois Urbana Champain and is visiting SIMM lab through the end of next summer. Her research interests span from soft-polymeric-materials characterization to plant-inspired motion to tissue-inspired design. She received all her degrees in Chemical Engineering, Ph.D. and M.S. from Caltech and B.S. from Oklahoma State. She was awarded an NSF CAREER award in 2017 and identified as an Emerging Investigator by Soft Matter in 2021.