Disposable Chips

Disposable Chips

Thursday, July 01, 1999
While other electronics engineers were knocking themselves silly to make better silicon chips, Dago de Leeuw decided to work with a different material: plastic. Although people have known for years that some polymer plastics are good at conducting electricity, it took de Leeuw and his team at Philips Research Laboratories in the Netherlands to figure out how to transform them into integrated circuits.

De Leeuw says the basic motivating idea was: "Don't compete with silicon. We are not going to make plastic Pentiums." Instead, he and his colleagues planned to create low-end circuits for high-volume applications—in essence, disposable electronics.

These all-polymer circuits are made in a process similar to the way silicon chips are manufactured but under less stringent conditions, which greatly reduces cost. De Leeuw used stock fabrication techniques and easily created different layers of the integrated circuit. But working with the polymers introduced unfamiliar problems. His team experimented with many different shapes until he hit on a complicated geometry that allowed the layers of the electrode to work together properly. And the researchers had to invent a way to make the vertical connections between layers that allow them to carry out logic operations. They replaced the silicon-coated tunnels of conventional chips with minute holes punched through overlapping contacts in the bottom and top layers of the plastic.

The electronic properties of conducting polymers don't come close to matching those of silicon, but they don't need to. "We concentrate on relatively simple electronic circuits with a low performance," says de Leeuw. The upside is that the plastic chips happen to be quite flexible. They function perfectly even when sharply bent, making them ideal for applications where rigid silicon chips would be useless. They might, for example, be used for antitheft stickers on luggage, rugged electronic toys and games, or packaging material that identifies its contents.

FINALISTS Honey, I Shrunk the Hard Drive INNOVATORS: Thomas Albrecht, Timothy Reiley, IBM Almaden Research Center

Some of the most intriguing new electronic devices are limited by the amount of information they can store. One solution was to develop a downsized version of the disk drive.

Thomas Albrecht, manager of mechanical technology for advanced drives at IBM Almaden Research Center, says it took the imagination and perseverance of his colleague Timothy Reiley to bring such a Microdrive to reality. The result is a memory disk about the size of a quarter that stores 5 billion bits per square inch.

Silicon Meets Paper INNOVATOR: Joseph Jacobson, Massachusetts Institute of Technology

Computers are great at retrieving information, but even avowed tech-heads have to admit that words on paper are a lot more pleasant to look at. So Joseph Jacobson and his colleagues at MIT are developing electronic ink—a radical computer output that looks and feels more like newspaper.

His ink contains microencapsulated spheres, each no wider than a human hair, which hold minute particles immersed in a liquid. A dense array of the tiny dots makes up letters as clear as the ones you're reading, and they can be coated onto almost any surface, including paper.
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