Ulrich S. Schubert talks with
ScienceWatch.com and answers a few questions about
this month's Fast Moving Fronts paper in the field of
Article: Inkjet printing of polymers: State of the art
and future developments
Authors: de Gans, BJ;Duineveld, PC;Schubert, US
Journal: ADVAN MATER, 16 (3): 203-213 FEB 3 2004
Addresses: Eindhoven Univ Technol, Lab Macromol Chem &
Nanosci, Dutch Polymer Inst, POB 513, NL-5600 MB Eindhoven,
Eindhoven Univ Technol, Lab Macromol Chem & Nanosci, Dutch
Polymer Inst, NL-5600 MB Eindhoven, Netherlands.
Philips Res, NL-5656 AA Eindhoven, Netherlands.
Why do you think your paper is highly
The paper is highly cited because the interest in inkjet printing has grown
significantly over the last several years. Inkjet printing is a relatively
new technique in scientific research and, in 2004, only a small number of
groups explored this field for science. Currently, many groups are using
inkjet printers to aid their research because:
1. Printers have become more reliable, more precise and, most importantly,
2. Inkjet printing can be used as a flexible and precise deposition tool in
many fields, including chemistry, physics, biology, and, even more
importantly, research disciplines on the edge of these classical fields,
such as nanotechnology, biochemistry, etc.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
"Inkjet printing has the benefit of being
flexible—one can rapidly change the image that will
be printed without making a new mask."
The paper describes the usage of an inkjet printer for a broad field of
applications. For example, the manufacturing of multicolor polymer
light-emitting diodes (PLED), polymer electronics, three-dimensional
printing, and also controlled drug release. These fields that had been
mentioned in 2004 have also emerged in the past five years. Therefore, the
topic is still "hot" as can be seen in recently published results from our
group: a review on inkjet printing of bio-materials (Soft Matter
5: 4866-77, 2009) and new results on the usage of inkjet printing for
flexible electronics applications (Adv. Mater. 21: 4830-34, 2009).
Furthermore, inkjet printing can be used as a rapid materials screening
tool (Soft Matter 4: 703-13, 2008). By printing a polymer
solution, one can study, for example, the photoluminescence properties of
the resulting printed films, while only using tiny amounts of the
(synthesized) polymer. In this way, a polymer selection for photovoltaic
devices, such as solar cells, could be done in a much more efficient manner
by reducing waste and enhancing the number of characterized samples in
time. In a traditional way, polymers would be tested one by one, which also
takes more time.
Would you summarize the significance of your paper
in layman's terms?
Inkjet printing is a technique where tiny amounts of droplets are dispensed
from a nozzle. The fluid is referred to as the "ink" and usually consists
of a liquid carrier and solute materials, for example small pigments when
having a colored ink. Instead of printing pigments, inkjet printing has
more and more been used to dispense complex fluids, for example, conductive
nanoparticles to make very small interconnects on a circuit board.
Moreover, biomaterials can be easily printed, since they are all
water-based and later used, e.g., for biosensors.
How did you become involved in this research and
were any particular problems encountered along the way?
The limits of inkjet printing lie in the fluid characteristics of the ink.
The ink must have certain rheological properties in order to be printable:
the viscosity should be low enough, and the size of particles present in
the ink should be sufficiently smaller than the nozzle aperture.
Where do you see your research leading in the
One field that is currently emerging is the field of inkjet printed
biomaterials. Various proteins, as well as DNA, can be printed and thereby
open new routes to functional bio-sensors. Secondly, inkjet printing of
microelectronic devices is an important field, since the technique is
flexible and dispenses materials only on demand. Finally, inkjet printing
shows a great benefit from being used in the field of materials screening:
a direct approach to study materials in a waste-efficient and
Do you foresee any social or political
implications for your research?
Inkjet printing has the benefit of being flexible—one can rapidly
change the image that will be printed without making a new mask. Therefore,
customized devices, tailored for each customer, can become possible.
Furthermore, printed electronics will drive newspapers toward being
produced on foldable, flexible displays, and each morning being uploaded to
the device. People will learn to live in a world that is less based on
paper and more on an efficient way of handling the global consumption of
energy and fossil fuels.
Prof. Dr. Ulrich S. Schubert
Laboratory of Organic and Macromolecular Chemistry
Friedrich-Schiller-Universität Jena & Dutch Polymer
Laboratory of Macromolecular Chemistry and Nanoscience
Eindhoven University of Technology & Dutch Polymer Institute
Eindhoven, The Netherlands Web |