Stretchy, conductive films made of novel nanobuds could bring touch sensors to more surfaces.
Transparent films containing carbon nanobuds —molecular tubes of
carbon with ball-like appendages—could turn just about any surface,
regardless of its shape, into a touch sensor.
The films were developed by a Finnish startup,Canatu, and could be
used to add touch controls to curved automobile consoles and dashboards,
for example. The films are rugged and can be repeatedly bent around
something as thin as the cord for your earbuds, so they could be handy
for adding buttons to flexible devices.
Touch screens are usually made by overlaying a display screen with a
transparent sheet of indium tin oxide. This material is brittle,
however, and can’t be used on anything other than a flat surface.
Individual carbon nanotubes have long been seen as a promising
alternative because they conduct electricity so well. But carbon
nanotubes have performed badly in touch screens due to poor electrical
connections between different nanotubes. Carbon nanobuds are better
because the ball-like appendages are particularly good at emitting
electrons, which improves those electrical connections.
A nanobud consists of a tube of carbon atoms with a bud-like appendage.
Canatu has 40 prototype products in the works. It recently built its
first full-scale manufacturing equipment, which can produce enough film
to cover hundreds of thousands of smartphone touch screens every month.
Next year the company plans to install enough machines to supply
millions of smartphones.
Films containing carbon nanotubes have previously been too expensive
to produce commercially. Canatu’s founders, researchers at Aalto
University, in Finland, improved the electrical connections between
carbon nanotubes by modifying their shape, and also found a way to make
nanobud films cheaply.
Making carbon nanotubes films conventionally is a complex process
that requires costly purification steps that can sometimes damage the
nanotubes. Canatu’s manufacturing approach starts with carbon-containing
gases, which are converted directly into nanobuds and deposited to make
a transparent film in one step, without the need for purification.
The material isn’t a good fit for all applications, though. The
conductivity isn’t high enough for very large screens, for example.
But the nanobud films can stretch over a surface, says
Erkki Soininen, vice president of marketing and sales, sometimes by more
than 200 percent without losing much performance. Most other
stretchable touch screens stretch by only a few percent. The material
stretches because the carbon nanobuds are able to slide past one another
while maintaining good electrical contact.
Title :
“Nanobuds” Could Turn Almost Any Surface into a Touch Sensor
Description : Stretchy, conductive films made of novel nanobuds could bring touch sensors to more surfaces. Transparent films containing carbon nan...
Rating :
5