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Frisbees sport recycled beach plastic
Axion Polymers, UK, processed a total of 88 kg of assorted plas-
tics collected from six area beaches in last year’s Big Beach Clean-Up
organized by the Marine Conservation Society
and Marks & Spencer (M&S). M&S used that
plastic to create their Beach Clean Frisbee. Ex-
tensive testing at Axion’s Salford facility proves
that rigid plastic debris, such as small toys and
bottle tops, can be recycled into new products.
“We applaud M&S for their efforts. Using
plastic from litter to create new products is
clearly an interesting approach, yet it’s only the
tip of the iceberg in terms of the opportunity
that exists to use recycled plastics from all
sources in new consumer goods,” says Axion di-
rector Keith Freegard. .
Building spaceships with artificial bone
Using a high-tech 3D printer, scientists at the Karlsruhe Insti-
tute of Technology, Germany, created a lightweight but very strong
material inspired by the intricate microscopic architecture of bones.
The research could pave the way for future super-light materials that
could be used in microfluidics devices or to make lighter, less ex-
pensive spacecraft.
Even though experts have managed to make artificial cellular ma-
terials like aluminum foam, which is full of air pockets and much
lighter than solid metal, there’s a trade-off—the porous metal is
much weaker than its solid counterpart. Engineering strong mate-
rials less dense than water (about 1000 kg/m3 ) is not easy to do.
Researchers used a 3D laser lithography machine to build very
tiny microstructures out of a ceramic-polymer composite. They made several different designs, from cubic
grids with diagonal supports to hexagonal honeycomb-like structures. These light building materials were re-
markably tough, exceeding the strength-to-weight ratio of all engineering materials with a density less than that
of water, say researchers.
Shock-absorbing bone goo offers osteoporosis insight
A team from Cambridge’s Department of Chemistry and Advanced Imaging
Centre, UK, used a combination of NMR spectroscopy, x-ray diffraction, imaging,
and computational modeling with the Department of Physics and Astronomy at
University College London to reveal citrate layers in bone. Citrate, a by-product
of natural cell metabolism, mixes with water to create a viscous fluid that is
trapped between the nanoscale crystals that form bones. The fluid allows enough
movement, or slip, between these crystals so that bones are flexible and do not
shatter under pressure. If citrate leaks out, the crystals—made of calcium phos-
phate—fuse together into bigger and bigger clumps that become inflexible, increasingly brittle, and more likely
to shatter. This could be the root cause of osteoporosis.
“Bone mineral was thought to be closely related to this substance called hydroxyapatite. But what we’ve shown
is that a large part of bone mineral—possibly as much as half of it—is made up of this goo, where citrate is binding
like a gel between mineral crystals,” says Melinda Duer, who led the study. “This nanoscopic layering of citrate fluid
and mineral crystals in bone means that the crystals stay in flat, plate-like shapes that have the facility to slide with
respect to each other. Without citrate, all crystals in bone mineral would collapse together, become one big crystal,
and shatter.” For more information: Melinda Duer, 012.233.36483, , .
ADVANCED MATERIALS & PROCESSES • JUNE 2014 6
interest
of material
Mars Express spacecraft after release of the
Beagle 2 lander. Courtesy of ESA.
Beach Clean
Frisbee made
from recycled
plastic
collected at UK
beaches.
Knee with patella x-ray.
Courtesy of Eric
Schmuttenmaer.