Silicon may underpin the computers that surround us, but the rigid inflexibility of the semiconductor means it cannot reach everywhere. The first computer processor and memory chips made out of plastic semiconductors suggest that, someday, nowhere will be out of bounds for computer power.
Researchers in Europe used 4,000 plastic, or organic, transistors to create the plastic microprocessor, which measures roughly two centimeters square and is built on top of flexible plastic foil. "Compared to using silicon, this has the advantage of lower price and that it can be flexible," says Jan Genoe at the IMEC nanotechnology center in Leuven, Belgium. Genoe and IMEC colleagues worked with researchers at the TNO research organization and display company Polymer Vision, both in the Netherlands.
The processor can so far run only one simple program of 16 instructions. The commands are hardcoded into a second foil etched with plastic circuits that can be connected to the processor to "load" the program. This allows the processor to calculate a running average of an incoming signal, something that a chip involved in processing the signal from a sensor might do, says Genoe. The chip runs at a speed of six hertz-on the order of a million times slower than a modern desktop machine-and can only process information in eight-bit chunks at most, compared to 128 bits for modern computer processors.
Organic transistors have already been used in certain LED displays and RFID tags, but have not been used to make a processor of any kind. The microprocessor was presented at the ISSCC conference in San Jose, California, last month.