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A D V A N C E D M A T E R I A L S & P R O C E S S E S | S E P T E M B E R 2 0 1 5
8 OMG!
OUTRAGEOUSMATERIALSGOODNESS
SUSTAINABLE SURFING
Researchers at the University of
California, SanDiego created theworld’s
first algae-based, sustainable surfboard.
Today’s polyurethane surfboards are
made exclusively from petroleum.
In order to make the precursor of
the polyurethane foam core of a surf-
board from algae oil, students first de-
termined how to chemically change the
oil obtained from laboratory algae into
different kinds of polyols. Mixed with a
catalyst and silicates in the right pro-
portions, these polyols expand into a
foam-like substance that hardens into
the polyurethane that forms a surf-
board’s core.
Although the board’s core is made
from algae, it is pure white and indis-
tinguishable from most plain petro-
leum-based surfboards. “In the future,
we could make the algae surfboards
‘green’ by adding a little color from the
algae to showcase their sustainability,”
says biology professor Stephen May-
field. “But right nowwe wanted tomake
it as close as we could to the real thing.”
For more information: Stephen Mayfield,
.
INVISIBILITY CLOAKS
AS TEACHING TOOLS
Real-life invisibility cloaks do exist,
in a manner of speaking—researchers
have engineered systems that bend
light around an object, shielding it from
detection. But most are tiny and only
work at very small wavelength rang-
es, rendering them unimpressive to
average observers. Now, a group of re-
searchers from the Karlsruhe Institute
of Technology (KIT), Germany, devel-
oped a portable cloak that can be taken
into classrooms and used for demon-
strations. It can’t hide a human, but it
can make small objects disappear from
sight without specialized equipment.
The cloak was constructed from a
light-scattering material. By dispersing
light, the material slows down the ef-
fective propagation speed of the light
waves through the medium. The light
can thenbe spedupagain tomakeup for
the longer path length around the hid-
den object. An object is placed inside a
hollowmetal cylinder coated with acryl-
ic paint, which diffusely reflects light.
The tube is embedded within a block
of polydimethylsiloxane, a commonly
Are you working with or have you
discovered a material or its properties
that exhibit OMG - Outrageous
Materials Goodness?
Send your submissions to
Julie Lucko at
.
Workers at Avila Surfboards in Oceanside, Calif., prepare the world’s first algae
surfboard blank for the application of a fiberglass shell. Courtesy of Erik
Jepsen/UC San Diego Publications.
In a diffusive light-scattering medium,
light moves on randompaths. A normal
object casts a shadow; an object with an
invisibility cloak does not. Courtesy of
R. Schittny, KIT.
used organic polymer, doped with tita-
nium dioxide nanoparticles that make it
scatter light.
NEW FURNITURE MATERIAL
WITHSTANDS FIRE AND WATER
Resource-saving wood-polymer
composites (WPCs) are the latest trend
in materials for garden furniture and
other outdoor applications, especial-
ly for terrace decking and panels used
for weatherboarding and fencing. Re-
searchers at the Fraunhofer Institute
for Wood Research, Wilhelm-Klauditz-
Institut WKI, Germany, are collaborat-
ing with industrial partners to devel-
op materials suitable for pressing into
moisture-resistant WPC boards for in-
door furniture manufacturing.
The boards are composed of
roughly 60% wood particles and 40%
thermoplastic material, generally poly-
propylene or polyethylene. Both wood
and plastic components can be sourced
from recycling streams. The wood com-
ponent in WPC boards can be replaced
by other lignocellulose products de-
rived from the fibrous part of plants
such as hemp or cotton or the husks
of rice grains and sunflower seeds. All
of these materials are 100% recycla-
ble and formaldehyde-free.
WPC board without (above) and with
(below) flame-proofing. Courtesy of
Fraunhofer WKI.