Wrinkles are all around us — on hanging curtains, the skin of drying fruit, or a surprised forehead. The more a material is squished, the deeper and taller the wrinkles become, until they collapse into a fold. Typically, this process depends strongly on the materials in question, for example the thickness of the skin, or the softness of the flesh underneath. However, we show that a wrinkle-to-fold transition may be affected only by the shape of the compressed object, rather than by any mechanical properties! Continue reading “Geometry-driven folding in PRL”
The group welcomes postdoctoral researcher Yousra Timounay. Yousra comes from the groups of Florence Rouyer and Elise Lorenceau at the Navier Laboratory in Paris, France. Welcome, Yousra!
The Paulsen Group was recently awarded a “Doctoral New Investigator” grant from the ACS Petroleum Research Fund, for a project titled: “Hyperuniform Dispersal of Non-Brownian Particles in Viscous Liquids”. See a video profile here. Continue reading “Grant from American Chemical Society”
“Curvature-induced stiffness and the spatial variation of wavelength in wrinkled sheets” appeared in PNAS (link). This work proposes and experimentally tests a basic framework for predicting wrinkle wavelengths in curved and/or non-uniform topographies. Continue reading “Wrinkling on curved surfaces in PNAS”
Recent work on wrapping liquid droplets with thin elastic sheets was highlighted in a UMass Amherst press release, which was picked up by numerous news sites. Stories were also written in Gizmodo (here and here), nanotechweb.org, AIMResearch, prophysik.de, and in Syracuse University’s “Headlines from the Hill”.
“Optimal wrapping of liquid droplets with ultrathin sheets” appeared in Nature Materials (link). This work explains the wide variety of shapes that can form when a very thin elastic sheet wraps itself around a liquid drop. Continue reading “Wrapping droplets with thin sheets in Nature Materials”