Soft machines and the mechanics of growing helical strips

Seminar
Speaker
Prof. Eran Sharon, The Racah Institute of Physics, HUJI
Date
22/04/2013 - 13:30Add to Calendar 2013-04-22 13:30:00 2013-04-22 13:30:00 Soft machines and the mechanics of growing helical strips   Many natural structures are made of soft tissue that undergoes complicated shape transformations as a result of the distribution of local active deformation of its "elements". Currently, the ability of mimicking this shaping mode in manmade structures is poor. I will present some results of our study of actively deforming thin sheets. We formulated a covariant elastic theory from which we derive an approximate 2D plate/shell theory for sheets with intrinsic incompatible metric and curvature tensors. With this theory we study selected cases of special interest. Experimentally, we use environmentally responsive gel sheets that adopt prescribed metrics upon induction by environmental conditions. With this system we study the shaping mechanism in different cases of imposed metrics and curvature. I will focus on different mechanisms that form helical ribbons and will show how the mechanism of seed pod opening is related to shape selection in self assembled chiral macromolecules. Room 301, Physics Bld. 202 Department of Physics physics.dept@mail.biu.ac.il Asia/Jerusalem public
Place
Room 301, Physics Bld. 202
Abstract

 

Many natural structures are made of soft tissue that undergoes complicated shape transformations as a result of the distribution of local active deformation of its "elements". Currently, the ability of mimicking this shaping mode in manmade structures is poor.

I will present some results of our study of actively deforming thin sheets.

We formulated a covariant elastic theory from which we derive an approximate 2D plate/shell theory for sheets with intrinsic incompatible metric and curvature tensors. With this theory we study selected cases of special interest.

Experimentally, we use environmentally responsive gel sheets that adopt prescribed metrics upon induction by environmental conditions. With this system we study the shaping mechanism in different cases of imposed metrics and curvature.

I will focus on different mechanisms that form helical ribbons and will show how the mechanism of seed pod opening is related to shape selection in self assembled chiral macromolecules.

Last Updated Date : 05/12/2022