Issue no. 40, 2008
Published: Dec 12, 2008 |
|
 Life-saving lab made from paper and sticky tape |
| Micro-origami lets scientists get a grip |
| Scientists develop way to display thoughts |
| A step closer to self-powered kit |
| Mobile phone chip to counter radiation unveiled |
| Crystals turn roads into power stations |
|
| Life-saving lab made from paper and sticky tape |
Origami artists can turn paper into all manner of ingenious objects. It
is unlikely, though, that anyone has tried to make a functioning medical
lab that way - until now. A portable testing kit made of paper could
transform medical care in poor countries.
Much diagnosis depends on tests of body fluids, such as for sugar in
urine or viral proteins in mucus. Some such tests are now automated in
'labs on a chip' that pipe biological samples through tiny channels into
cavities containing reagents that change colour to reveal the result.
However, these microfluidic devices are expensive and fragile.
Researchers at Harvard University cut precise patterns of tiny channels
in sheets of paper and interleaved them with double-sided carpet tape
laser-drilled with corresponding patterns of holes. The paper wicks
water along the channels, making pumps unnecessary, and the holes
connect paper layers to form a three-dimensional maze. Samples applied
to one side of the device end up in chambers pre-packed with reagents
for different substances. The team's prototype measured sugar in urine,
but in principle the device could do many tests at once.
A photo of the coloured dots that reveal the results could be sent by
cellphone to a specialist centre for diagnosis, and the devices are
light, cheap and rugged - good news for healthcare in poor countries. |
| New Scientist / Proceedings of the National Academy of Sciences
Dec 10, 2008 |
 back to top
|
|
| Micro-origami lets scientists get a grip |
Picking up dropped sewing needles can be tricky enough, so imagine the
problems of manipulating objects on the microscale. To try and make such
tasks easier, Scientists at Johns Hopkins University in the US have now
developed a mechanical gripper the size of an amoeba, and used it to
pick up and drop microscopic beads, wires and tubes.
The microgripper is shaped like a star, with six arms equally spaced
around a hexagonal centre. Constructed from gold-plated nickel, it is
around 700 micrometres wide when fully open, shrinking to 200
micrometres with the arms folded. Each of the arms is attached by a
three-layered joint comprised of a very thin layer of chromium, just 50
nanometres thick; a thicker layer of copper (250 nm); and a much thicker
layer of polymer resin (3500 nm).
The secret to the device's gripping action is that the copper layer is
under tension - naturally bent but restrained in a flattened form by the
polymer layer. In its idle state, the microgripper is open. To close it
the researchers simply expose it to acetic acid - the key ingredient in
vinegar. The restraining polymer resin is dissolved by the acid, freeing
the springy copper to bend, and causing the device to close. To then
relax the hold the microgripper is exposed to hydrogen peroxide, which
dissolves the copper layer. This leaves behind just the thin chromium
layer, which folds the arms flat once more. |
| New Scientist / Journal of the American Chemical Society
Dec 09, 2008 |
back to top
|
|
| Scientists develop way to display thoughts |
A Japanese research team says it has created a technology that could
eventually display on a computer screen what people have on their minds,
such as dreams.
Researchers at the ATR Computational Neuroscience Laboratories succeeded
in processing and displaying images directly from the human brain, they
said in a study unveiled ahead of publication in the US magazine Neuron.
While the team for now has managed to reproduce only simple images from
the brain, they said the technology could eventually be used to figure
out dreams and other secrets inside people's minds.
When people look at an object, the eye's retina recognises an image that
is converted into electrical signals which go into the brain's visual
cortex. The team succeeded in catching the signals and then
reconstructing what people see. In their experiment, the researchers
showed people the six letters in the word 'neuron' and then succeeded in
reconstructing the letters on a computer screen by measuring their brain
activity. The team first figured out people's individual brain patterns
by showing them some 400 different still images. |
| Sydney Morning Herald / AFP
Dec 11, 2008 |
back to top
|
|
| A step closer to self-powered kit |
Engineers have doubled the efficiency of piezoelectric devices that
harvest energy from movement and vibration. The trick lies purely in the
size of the devices: a narrow range of thicknesses around 5,000 times
thinner than a human hair. The result means that 'self-powered' devices,
such as phones that charge when you speak into them, are one step closer
to reality.
The piezoelectric effect occurs in some crystalline and ceramic
materials. Stretching or compressing them causes a separation of
electric charge across their width, and that sets up a voltage that can
be put to use. Such piezoelectric materials have been in use for years
in devices such as electronic lighters and microphones, where pressure
from a thumb or even a sound wave is harvested. However, the behaviour
of materials in comparatively large devices can change radically when
pared down to the nanometre scale.
Researchers at Texas A&M University have found that when piezoelectric
materials are made in a narrow size range around 20 nanometres, a new
effect comes into play. This 'flexoelectric effect' produces a voltage
from twisting and bending, instead of the uniform compression or
stretching as in piezoelectricity. The researchers proved that the
effect can be maximised in nano-scale cantilevers by tailoring the
cantilevers' shape. The new results mean that such sounds or vibrations
produce significantly more charge that can be gathered up and put to
use. That means that Piezoelectrics tailored at the nano-scale could
directly power small devices or charge a battery. |
| BBC News / Physical Review B.
Dec 04, 2008 |
back to top
|
|
| Mobile phone chip to counter radiation unveiled |
Belgian health products distributor Omega Pharma this week launched a
chip it claims can counter potentially damaging radiation from mobile
phones and has high hopes for its sales.
Testing of the E-waves phone chip, which offsets the electromagnetic
radiation from the phone, showed it lessened symptoms such as headaches
and loss of concentration that might be associated with mobile phone
use, Omega said. It also neutralised the heating effect within the body
produced by electromagnetic signals. Omega will also launch three
similar devices designed for use in the car, linked to a computer and in
the home.
The scientists who have developed the chip argue there is a growing body
of evidence showing a link between mobile phone use and the growth of
tumours. However, scientists worldwide remain split between those that
believe there is a risk and others who believe there is insufficient
evidence to show mobile phones are unsafe. |
| Reuters
Dec 09, 2008 |
back to top
|
|
| Crystals turn roads into power stations |
An environmentally friendly road that positively welcomes heavy traffic
may sound odd, but by placing piezoelectric crystals under the asphalt
that convert vibration into electricity, Israeli engineers hope to
harvest energy from passing vehicles.
Developer Haim Abramovich at the Technion-Israel Institute of Technology
in Haifa says the crystals can produce up to 400 kilowatts from a
1-kilometre stretch of four-lane highway. His spin-out company,
Innowattech, also based in Haifa, will begin testing the system on a
100-metre stretch of road in northern Israel in January.
Installing the technology need not produce unnecessary greenhouse gases,
says Abramovich: 'We're advocating that the system be fitted to roads
only during routine maintenance, so there's no extra digging.' |
| New Scientist
Dec 10, 2008 |
back to top
|
