All-nanowire loaded chip

Just after blogging on UC Berkeley’s recent research gift from Applied Materials, this story appears in the inbox. The university has created the first integrated circuit using nanowires as both sensors and electronic components.

This technology has a lot of possibities, even beyond silicon chips.

From the second link:

Nanowires make good sensors because their small dimensions enhance their sensitivity. Nanowire-based light sensors, for example, can detect just a few photons. But to be useful in practical devices, the sensors have to be integrated with electronics that can amplify and process such small signals. This has been a problem, because the materials used for sensing and electronics cannot easily be assembled on the same surface. What’s more, a reliable way of aligning the tiny nanowires that could be practical on a large scale has been hard to come by.

A printing method developed by the Berkeley group could solve both problems. First, the researchers deposit a polymer on a silicon substrate and use lithography to etch out patterns where the optical sensing nanowires should be. They then print a single layer of cadmium selenide nanowires over the pattern; removing the polymer leaves only the nanowires in the desired location for the circuit. They repeat the process with the second type of nanowires, which have germanium cores and silicon shells and form the basis of the transistors. Finally, they deposit electrodes to complete the circuits.

Squared away: University of California, Berkeley, researchers were able to create an orderly circuit array from two types of tiny nanowires, which can function as optical sensors and transistors. Each of the circuits on the 13-by-20 array serves as a single pixel in an all-nanowire image sensor.