Simple rules for the wrinkle patterns of confined elastic shells

by Dr Ian Tobasco (University of Illinois, Chicago)

Tuesday 2 Mar 2021, 15:00 → 16:00 Europe/Stockholm

 The zoom link  :

https://stockholmuniversity.zoom.us/j/622224375

Meeting ID: 622 224 375

 

 

Dried fruits wrinkle for the same reason that leaves and flowers do — mechanical instabilities arising from a mismatch in lengths. Can such geometric incompatibilities be used to design and control wrinkle patterns at will? This talk will discuss the possibility of designing wrinkle patterns "in the large" using a recently derived model for the wrinkles of confined elastic shells. After recalling the basic mechanics and introducing our model, we show how it can be solved by hand in many cases to predict the wrinkled topography. Our solution formulas take the form of a few geometric rules, which explain the layout of the wrinkle peaks and troughs. These simple rules reproduce the patterns seen in numerous experiments and simulations, even ones that exhibit a surprising coexistence between orderly wrinkles and a more disordered response. Knowing such rules for wrinkles opens the way towards designer wrinkle patterns, with potential applications ranging from flexible electronics to synthetic skins.