Paper Transistors

2 min read

Paper Transistors

Scientists at Infineon Technologies, Erlangen, Germany, have fabricated organic transistors and circuits on commercially available cotton-fiber paper--a neat trick, considering paper is hardly an ideal circuit substrate. Its fibrous surface is rough, whereas a typical semiconductor substrate such as silicon is smooth; it soaks up processing chemicals like a sponge; and it would burst into flames at normal semiconductor fabrication temperatures.

Infineon worked around the combustion problem by relying on the semiconducting organic material pentacene, which is workable at relatively low temperatures. And the researchers solved the sponginess problem by coating the paper with a polymer film less than a micrometer thick. The paper's inherent roughness forced Infineon to make the transistors about 100 times as large as those you'd find on a silicon circuit, resulting in much slower switching times.

Organic Electronics on Paper , by Florian Ender et al., Applied Physics Letters, 5 April 2004, pp. 2673-75.

Open VS. Closed

Is open-source software development everything its proponents say it is? Researchers in Canada, Italy, and the United Arab Emirates discovered that the answer is: not quite. They developed a set of metrics and used them to gauge whether open-source development really fosters faster system growth, leads to more creativity, produces less complex code, results in fewer bugs, and makes more modular software. They analyzed three well-known open-source projects and three closed-source projects (which they had to keep confidential).

The researchers found evidence to support only two of the five claims. The open-source projects do seem to foster more creativity and usually yield fewer bugs. The evidence suggests that the other three beliefs are not true. Open-source software may, in fact, actually be more complex and less modular.

An Empirical Study of Open-Source and Closed-Source Software Products , by James W. Paulson et al., IEEE Transactions on Software Engineering, April 2004, pp. 248-56.'

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