"Experiments at the Intersection of Geometry, Mechanics, and Microstructure"

Speaker: 
Jesse Silverberg
Institution: 
Harvard Univ.
Date: 
Thursday, April 30, 2015
Time: 
3:30 pm
Location: 
RH 101

*Refreshments to follow in Rowland Hall 142

 


ABSTRACT:  

Climbing cucumbers, popping pollen grains, wrinkled fingers, and curly hair.  At heart, the modern revival of mechanics covers a diverse range of subjects at the intersection of function and form.  It's at this point – where geometry, mechanics, and microstructure meet – that we find buckling instabilities, mechanical phase transitions, exotic stress responses, and fracture.  These phenomena are widely observed in many inert materials, but remarkably, we also find them being actively employed in biological tissues where they have evolved as essential tools for survival.  My research explores this intersection of topics and draws on a wide range of experimental tools to better understand the microscopic origins of material non-linearities as well as their macroscopic consequences for living and non-living systems.

In this talk, I will discuss a series of experiments studying the physics of folded paper.  This work takes aim at the connection between the simple geometry of an origami folding pattern and the resulting bulk elastic properties.  While we find mechanical analogs of familiar condensed matter phenomena such as lattice defects, vacancies, and phase transitions, we also uncover a number of unexpected behaviors unique to thin folded sheets.  Probing these “reprogrammable mechanical metamaterials” ultimately leads to new insights on the emerging subject of elastic network materials, and a greater appreciation for the art-form itself.


Harvard University, Wyss Institute for Biologically Inspired Engineering

Host: 
Clare Yu