Among the most useful tools for nanotechnology are various scanning probe tips for surface modification. A few years ago, the IBM Millipede project demonstrated the use of an array of silicon cantilevers as a nanotech memory device (see Millipede comes out of the lab) that operates by making and erasing nanometer-scale marks. In Technology Review, Kevin Bullis describes another approach to computer memory based upon similar arrays of atomic force probe tips. A few excerpts from “Higher-Capacity Memory“:

An alternative to the flash memory that stores and retrieves data with arrays of microscopic probes could soon be on the market. Nanochip, a company based in Fremont, CA, has recently raised $14 million to complete work on prototypes that it hopes to ship to electronics device makers for evaluation next year.

Nanochip’s technology offers advantages to flash memory, both in terms of the amount of data that can be stored and the cost per memory chip, says Gordon Knight, the company’s CEO. The first prototypes will store about 100 gigabytes, he says—more than the tens of gigabytes stored on flash memory cards today. Eventually, the devices could store terabytes’ worth of data, he says. That’s likely out of the reach of flash-type memory, says Stefan Lai, formerly the director of flash memory technology at Intel and now a scientific advisor to Nanochip.

In flash memory, information is stored using specialized transistors, each of which is addressed by a grid of conducting wires. The Nanochip technology, in contrast, stores information by writing data to a thin-film material using an array of microscopic cantilevers, each with an extremely sharp tip. The size of each bit will be 15 nanometers in the first devices, but it could theoretically be as small as just a couple of nanometers.

The Millipede array works by heating and indenting a polymer, while the Nanochip array uses voltage to write electronically. Apparently with both methods the integration of the tip arrays into a complete memory chip remains a challenge. If this challenge can be met, perhaps this type of highly parallel tip-directed surface modification will also prove useful as a path toward atomically precise manufacturing.
—Jim

An interview by Nanotechnology.com of the director of the Center for Nanoscale Chemical-Electrical-Mechanical Manufacturing Systems got our attention. I’d give you a URL for this interview but it doesn’t seem to be on the web, only in email. An excerpt:

The molecular gate toolbit: This is a toolbit that uses efficient electrokinetic transport in long (high-aspect ratio) nanopores. These pores can be made with different diameters and surface properties to ‘select’ molecules from a stream and drive them to the printing surface for printing on to a substrate. We are working on creating a toolbit that embodies a large array of such nanopores that are electronically addressable so that they can be switched on and off to enable high-throughput printing of various biomaterials.

An interesting approach to using top-down nano to reach closer to the molecular level. A look at the Nano-CEMMS website shows that the center is joint project between UIUC, Caltech, NC State, and Stanford. Check out the site and enjoy their video “Thinking Big, Working Small“, which emphasizes the multidisciplinary nature of their work.

Thinking of nanotech as a career and selecting a university? UIUC is looking good. (Of course, that’s true of many of the better schools these days, but UIUC is not as well-known as Stanford, Caltech, and MIT. Maybe not for long, though!) The website says that even undergrads can work at the center. —Christine