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provide better understanding of a host
of newly designed materials, which of-
ten have complicated crystal structures
that give rise to unusual effects such
as high-temperature superconductivity.
RESEARCH EXPLORES
MYSTERY BEHIND
WRINKLED SURFACES
The reason why layered materi-
als sometimes form one kind of wrin-
kly pattern or another has now been
explained at a fundamental level by
researchers at Massachusetts Institute
of Technology, Cambridge. The under-
lying process is the same in all cases:
Layers of material with slightly differ-
ent properties tend to form patterned
surfaces when they shrink or stretch in
ways that affect the layers differently.
For the first time, the new analysis cre-
ates a unified model that shows exact-
ly how the properties of the individual
layers, and how they are bonded to
each other, determines the exact form
of the resulting texture.
MIT associate professor of me-
chanical engineering Xuanhe Zhao and
postdoctoral researcher Qiming Wang
report that the patterning process they
describe applies to everything from
the folds on the surface of the brain to
wrinkles on an aging face, and from the
buckling of tree bark to the ridged skin
of a pumpkin. By understanding the
factors that produce these patterns, re-
searchers say it should become easier to
design synthetic materials with exactly
the kinds of surfaces needed for specific
applications, such as better traction or
water-shedding properties. They also
expect that this model will not only be
MIT researchers explore why layeredma-
terials form one kind of wrinkly pattern or
another. Courtesy of Jose-Luis Olivares/
MIT.
helpful for understanding growth and
aging patterns in biological organisms,
but could also help in the design of
materials for disease treatment, cell
cultures, control of biofouling, control-
lable properties of water shedding, and
flexible electronic materials. For more
information: Xuanhe Zhao, 617.324.6367,
, .