Sensor of plastic can be produced in a printing press

Feb 08, 2005

Electrochemical transistors made of plastic open myriad possibilities. Since both electrons and ions are active, they can function as a bridge between traditional electronics and biological systems. A new dissertation from Linköping University in Sweden describes a simple and inexpensive humidity sensor that can be manufactured in a printing press.

Electrically conducting plastic is used today in field effect transistors, light-emitting diodes, electrochemical components, and batteries. Organic semiconductors are better than silicon because they can be applied to soft surfaces, even paper, using printing technology. What’s more, the components can be recycled in the same way as regular paper and plastic.

In an electrochemical transistor, both electrons and ions serve as charge bearers. It can be used in sensors, analytical tools, logical circuits, and smart displays. The current is controlled by a reduction/oxidation process, which means that it uses low-voltage current, roughly one volt, and is not dependent on small dimensions. Moreover, it has a memory function.

This dissertation by David Nilsson, from the Department of Science and Technology, describes an electrochemical humidity sensor, produced using purely organic materials. Depending on the humidity of the air, the conducting capacity of the electrolyte changes, as does the response from the transistor. The same concept can be used to gauge acidity (pH) or the content of ions and glucose.

The vision is for the sensor, the battery, and the display to be pressed simultaneously on paper or other flexible surfaces. In that way it would be possible to produce cheap electronic “litmus paper” or reaction strips for blood and glucose testing.

Intelligent image units (pixels) are another interesting application of electrochemical transistors. Varying the current alters the color of the display and thereby the content of the image or text. The technology can be used to develop smart labels and advertising signs.

David Nilsson is a member of Professor Magnus Berggren’s research team in organic electronics. In collaboration with the electronics research institute Acreo, the team has developed printing technology for electronics on paper. Recently the Swedish Research Council provided funding for another printing press under the project Electronic Paper Printing House.

Explore further: California puzzles over safety of driverless cars

add to favorites email to friend print save as pdf

Related Stories

Rohinni's Lightpaper invites innovative lighting

Nov 30, 2014

Rohinni's Twitter statement on what this company is all about is quite simple: We print light. Print light? This Coeur d'Alene, Idaho-based company is introducing its Lightpaper, with a promotional video ...

Chemists fabricate novel rewritable paper

Dec 02, 2014

First developed in China in about the year A.D. 150, paper has many uses, the most common being for writing and printing upon. Indeed, the development and spread of civilization owes much to paper's use as ...

Genomes of malaria-carrying mosquitoes sequenced

Nov 27, 2014

Nora Besansky, O'Hara Professor of Biological Sciences at the University of Notre Dame and a member of the University's Eck Institute for Global Health, has led an international team of scientists in sequencing ...

Princeton team explores 3D-printed quantum dot LEDs

Nov 06, 2014

Some of the most important developments marking advances in the 3D printing industry are in the realm of material science, notes 3d Printing Industry. "The more materials we can print, the more useful the ...

Recommended for you

Cyclist's helmet, Volvo car to communicate for safety

1 hour ago

Volvo calls it "a wearable life-saving wearable cycling tech concept." The car maker is referring to a connected car and helmet prototype that enables two-way communication between Volvo drivers and cyclists ...

California puzzles over safety of driverless cars

2 hours ago

California's Department of Motor Vehicles will miss a year-end deadline to adopt new rules for cars of the future because regulators first have to figure out how they'll know whether "driverless" vehicles ...

Britain's UKIP issues online rules after gaffes

2 hours ago

UK Independence Party (UKIP), the British anti-European Union party, has ordered a crackdown on the use of social media by supporters and members following a series of controversies.

Sony saga blends foreign intrigue, star wattage

3 hours ago

The hackers who hit Sony Pictures Entertainment days before Thanksgiving crippled the network, stole gigabytes of data and spilled into public view unreleased films and reams of private and sometimes embarrassing ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.