Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

In place fabrication solves organic polymer shortcoming

09.09.2003


Just like the manufacturers of silicon electronics, a team of Penn State chemical engineers wants to assemble circuit boards in place, but these circuits are made of conducting organic polymers that pose major fabrication roadblocks.



"We want to build electronic devices like transistors and flexible circuits," says Dr. Seong Kim, assistant professor of chemical engineering.

Kim and Sudarshan Natarajan, graduate student in chemical engineering, looked at fabricating circuits from polythiophene. This conjugate conducting organic polymer is easily made in a beaker, but once the polymer is created from chaining together a series of identical smaller molecules – monomers – it is a powder that cannot be molded or used for film coating.


"Conjugate conducting polymers are not soluble nor are they meltable," Kim told attendees at the annual meeting of the American Chemical Society today (Sept. 8) in New York. "Some researchers have made them soluble by adding elements to the polymer backbone, but making circuit boards with these is difficult and requires high energy."

Kim and Natarajan solve the fabrication problem by combining the synthesis and processing steps, which are done separately in conventional methods, into a single step.

"We bypass the problem," says Kim. "We make the material at the site of application."

The researchers use a prepared substrate and deposit the monomer – the small molecule that chains to make the polymer – using standard physical vapor deposition. Once they have a thin film of the monomer on the substrate, they apply a mask, similar to those used in standard silicon electronics manufacture, to the surface. The masked monomer film is then exposed to ultraviolet light.

The light causes two monomers to join forming a dimer, then a third molecule to form a trimer and so on. Dimers and trimers then join to begin forming the much longer polymer chains until all the monomer exposed to light is polymerized.

This reaction differs from normal polymerization where the chain begins at one point and grows by adding individual monomers. In this new process, monomers are joining each other wherever they are struck by the photons in the ultraviolet light. The process takes about seven minutes to complete. The researchers then wash off the soluble, uncoupled monomers, leaving only the pattern of conducting polymers indicated by the mask.

Aiming to incorporate conjugate conducting organic materials into the current silicon-based microtechnology, the researchers tried a variety of inorganic substrates including copper, gold and silicon.

However, neither copper nor silicon will make a flexible circuit, so the researchers are also investigating using other flexible substrates such as plastics. A circuit made on plastic materials would find applications where the flexibility is critical. For example, flexible circuits would be ideal for lightweight flexible-screen displays creating electronic paper.

A variety of conducting polymers are also light emitting. The proper combination of red, yellow and green can produce full color images. Another example would be in biomedical applications.

The researchers are looking at a variety of other organic conducting polymers for use in in-place fabrication of circuits and electronic devices.

A seed grant from Penn State’s National Science Foundation-supported Materials Research Science and Engineering Center seed grant supported this work.

A’ndrea Elyse Messer | EurekAlert!
Further information:
http://www.psu.edu/

More articles from Life Sciences:

nachricht Microscope measures muscle weakness
16.11.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

nachricht Good preparation is half the digestion
16.11.2018 | Max-Planck-Institut für Stoffwechselforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>