|Posted: March 1, 2010
Printable sensors from EU project 3Plast
(Nanowerk News) The cellphone is switched off but immediately springs into action at
the point of a finger. It is not necessary to touch the display. This
touchless control is made possible by a polymer sensor affixed to the
cellphone which, like human skin, reacts to the tiniest fluctuations in
temperature and differences in pressure and recognizes the finger as it
The scenario is fictitious at present but could become reality in a few
years time thanks to the efforts of the research scientists involved in
the EU project 3Plast, which stands for "Printable pyroelectrical and piezoelectrical large area sensor technology".
|The sensor recognizes the finger’s heat signal without being touched.
The companies and institutes
involved from industry and research have set themselves the goal
of mass producing pressure and temperature sensors which can be
cheaply printed onto plastic film and flexibly affixed to a wide range of
everyday objects, such as electronic equipment. The 2.2 million euro
funded project is coordinated by the Fraunhofer Institute for Silicate
Research ISC in Würzburg.
"The sensor consists of pyroelectrical and
piezoelectrical polymers which can now be processed in high volumes
by screen printing, for example. The sensor is combined with an organic
transistor, which strengthens the sensor signal. It’s strongest where
the finger is," explains Gerhard Domann, who is in charge of the project.
"The special thing about our sensor is that the transistor can also
The production of polymer sensors still poses a number of challenges.
To produce printable transistors, the insulation materials have to be
very thin. The experts at the ISC have, however, succeeded in producing
an insulator which is only 100 nanometers thick. The first sensors
have already been printed onto film. The research scientists are currently
working on optimized transistors which can amplify rapid
changes in temperature and pressure.
"By providing everyday objects with information about their environment
– for example whether a person is approaching – by means of
pressure and temperature sensors, we can create and market new devices
that can be controlled just by pointing a finger," enthuses Domann.
The research scientist envisions further applications for the
technology in the automotive and construction industries as well as in
"The project comes to an end in January 2011, but we think
it will take a few more years before sensors can be printed on large