Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Printing plastic circuits stamps patterns in place

10.09.2003


When Benjamin in "The Graduate" was told to go into plastics, computers were in their infancy and silicon technology ruled. Now, conducting organic polymers are infiltrating the electronics sphere and the watchword is once again plastics, according to Penn State researchers.



"For plastic circuits we cannot use the old processing," says Dr. Qing Wang, assistant professor of materials science and engineering. "Photolithography and silicon technologies require harsh environments and plastics cannot hold up to them."

Wang, working with Ziqi Liang and Kun Li, graduate students in materials science and engineering, are looking into novel processing methods for production of organic conducting polymer circuits. One method that is low cost, easy to do, fast and adaptable to large areas and non-flat surfaces, is micro contact printing.


"We use conducting polymers that are functionalized," Wang told attendees today (Sept. 9) at the annual meeting of the American Chemical Society in New York. "They have functional groups attached that allow them to be soluble and to attach to the surface." The researchers used poly (p-phenylene vinylene), PPV, which was modified by adding alkyoxy side chains and amino end groups. Altering the polymer allows it to dissolve in a variety of organic solvents. The amines act as reaction points where the polymer can attach to another chemical.

Attachment is important as most polymers are slippery and do not want to adhere to surfaces. In conventional ink printing, ink is held onto the paper by surface interactions, but not by chemical reactions. When printing a plastic electronic device, surface interactions are not strong enough to hold the polymer "ink" onto the surface.

Wang used a gold substrate onto which an organic acid, 16-mercaptohexadecanoic acid, was placed in a self-assembled monolayer. This single layer of molecules of MHA provides specific chemical groups to which the amino end groups of the polymer can attach.

In conventional printing, ink is placed on the plate and then the ink and paper are brought together for a very short time during which the wet ink is transferred to the paper. When printing polymers on organic acid coated gold, the process is different. The researchers used a pliable stamp of the submicron pattern they wish to transfer. They then applied the polymer "ink" to the stamp surface and dried it. The stamp and the substrate are held in contact for 30 minutes while the polymer transfers to the substrate.

Because the stamp is pliable, this printing method is applicable to curved surfaces. A wide variety of opto-electric devices are possible, including light-emitting diodes, field effect transistors, lasers, solar cells and chemical and biological sensors.

Wang has investigated the resulting patterns using a variety of macroscopic techniques to ensure that the pattern created on the surface is continuous and usable. Micro contact printing does create patterns with some defects, but the researchers believe that the resultant product is usable.

"Micro-printed patterns of conducting polymer need to be used in applications where some defects can be tolerated," says Wang.

"Although we do optimize the printed pattern as much as possible."

The Commonwealth of Pennsylvania’s Lehigh/Penn State Center for Optical Technologies supported this work.

A’ndrea Elyse Messer | Penn State
Further information:
http://www.psu.edu/

More articles from Materials Sciences:

nachricht From foam to bone: Plant cellulose can pave the way for healthy bone implants
19.03.2019 | University of British Columbia

nachricht Additive printing processes for flexible touchscreens: increased materials and cost efficiency
19.03.2019 | INM - Leibniz-Institut für Neue Materialien gGmbH

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

Im Focus: Revealing the secret of the vacuum for the first time

New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum

For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...

Im Focus: Sussex scientists one step closer to a clock that could replace GPS and Galileo

Physicists in the EPic Lab at University of Sussex make crucial development in global race to develop a portable atomic clock

Scientists in the Emergent Photonics Lab (EPic Lab) at the University of Sussex have made a breakthrough to a crucial element of an atomic clock - devices...

Im Focus: Sensing shakes

A new way to sense earthquakes could help improve early warning systems

Every year earthquakes worldwide claim hundreds or even thousands of lives. Forewarning allows people to head for safety and a matter of seconds could spell...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Levitating objects with light

19.03.2019 | Physics and Astronomy

New technique for in-cell distance determination

19.03.2019 | Life Sciences

Stellar cartography

19.03.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>