BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Rothschild Distinguished Visiting Fellow Lecture: Metamaterials: c
 omposite materials with striking properties - Graeme Milton (University of
  Utah)
DTSTART:20190603T150000Z
DTEND:20190603T160000Z
UID:TALK125377@talks.cam.ac.uk
CONTACT:INI IT
DESCRIPTION:Sometimes the properties of a composite are completely unlike 
 those of the constituent materials\, even when the structure is small comp
 ared to the wavelength: these composites are called metamaterials. Classic
  examples include bubbly fluids and stained glass windows made from suspen
 sions of metal particles in glass. Other examples include metamaterials wi
 th negative thermal expansion made from materials all having positive ther
 mal expansion\; metamaterials with negative and/or possibly anisotropic ma
 ss density over a range of frequencies\; metamaterials that get fatter as 
 they are stretched (having a negative Poisson&#39\;s ratio)\; materials wi
 th artificial and possibly negative magnetic permeability. The list goes o
 n. Recent attention has been directed to space-time microstructures where 
 the material moduli vary in both space and time. We will review some of th
 e progress that has been made. One particular class of elastic metamateria
 ls\, known as pentamodes\, has proved useful for guiding stress. Cable net
 works can also guide stress. It turns out that essentially any cable netwo
 rk under tension\, and supporting a given loading\, can be replaced by one
  in which at most four cables meet at any junction. Like pentamodes\, thes
 e can support\, up to a constant factor\, only one stress field. Thus by t
 ightening just one cable one gets the desired forces at all the terminal n
 odes. This last work is joint with Guy Bouchitte\, Ornella Mattei and Pier
 re Seppecher. <br>
LOCATION:Seminar Room 1\, Newton Institute
END:VEVENT
END:VCALENDAR