At drupa
print media fair, the world’s largest fair on print media
technology, which takes place from 3 to 16 May 2012 in Düsseldorf, the
Institute for Print and Media Technology of Chemnitz University of Technology
(pmTUC) presents new research results, which truly make you prick up your ears:
Loudspeakers that have been printed with flexography on standard paper. The
R&D group of Prof. Dr. Arved Hübler, head of pmTUC, is co-exhibitor of
press manufacturer Windmöller & Hölscher KG (Lengerich) and can be found in
hall 15, booth A41/1.

The printed paper loudspeaker is connected to an audio amplifier like a
conventional loudspeaker. “Frequency response and hence sound quality are
very good and the paper is surprisingly loud. Just the bass of the paper-based
loudspeaker is a bit weak”, explains Dr. Georg Schmidt, senior researcher
at pmTUC. The thin loudspeakers, which are printed in the laboratories of
pmTUC, contain several layers of a conductive organic polymer and a piezoactive
layer. According to project assistant Maxi Bellmann the loudspeakers are
astonishingly robust and can be produced in a very cheap way as mass printing
methods are used. The bottom side of the paper loudspeaker provides unused
space on which coloured messages can be printed.

Prof. Hübler expects a broad range of new applications: The paper
loudspeakers could, for instance, be integrated into common print products. As
such, they offer an enormous potential for the advertising segment. “In
addition, sound wallpapers and purely technical applications, e.g., distance
sensors, are possible, because the papers are also active in the ultrasound
range”, says Hübler and adds: “As printing allows for different
formats and forms, there is the possibility to influence the generated sound
waves.” The loudspeaker of pmTUC was realised within the framework of the
project Plastic Acoustics (PACU), which is funded by the Federal Ministry of
Education and Research and includes the following project partners: Robert
Bosch GmbH (Stuttgart), Heraeus Clevios GmbH (Leverkusen), X-Spex GmbH
(Berlin), and Fraunhofer Institute for Electronic Nano Systems ENAS (Chemnitz).

Electricity that grows on trees

Besides printed loudspeakers, pmTUC presents innovative application
scenarios for printed solar cells. “Half a year ago, we introduced the
world’s first 3PV technology– printed paper
photovoltaics, says Hübler. At drupa, the Chemnitz researchers exhibit a solar
tree with 50 printed solar leaves. Similar to an ordinary tree, the leaves that
face the sun collect energy. They are connected with snap fasteners. Via a
cable in the hollow tree trunk the solar electricity supplies a battery.

“If you stand below the tree and look up to the shade-giving leaves
of the solar tree, you can see that the bottom side of the leaves is printed
with advertisements”, explains Hübler and adds with a twinkle in his eye:
“That’s even better than in nature.” Because according to Hübler, the
advertising segment is the driving force of the printing industry: “As
soon as the customer realises that it is better to not throw advertising that
contains a solar cell away, but rather keep it to generate electricity for some
time, the printed solar cell will become an unbeatable advertising carrier with
a sustainable image”, reports the professor from Chemnitz. Hübler does not
only believe that the 3PV technology, developed at Chemnitz University of
Technology, will make a contribution to global power supplies in the future,
but also that 3PV will bring about the breakthrough of printed electronics.

In his book “print becomes electronics”, which is published in
English and German on occasion of drupa, Hübler analyses the backgrounds of
this development and explains the transition that he expects to take place in
the traditional graphic arts industry. According to Hübler, electronic media
and conventional print media will increasingly merge in the future: “A
large part of electronics will be printed, and most print media will be
electronic.” The book is available at drupa and upon request from pmTUC.