Roll Up For A Flexible Future

It is nice to read a newspaper on a light and large tablet, but what if you can roll it up too? What if you can fold your cellphone like a piece of paper, or you had devices with screens that do not break when dropped? You cannot do these things now because the displays and electronics are rigid structures. Flexible electronics and displays are being developed all over the world, and you can see them incorporated into devices beginning from this year.

Take, for instance, the camera developed by John Rogers, professor of materials science and engineering at the University of Illinois and Urbana Champaign. This tiny device, as big as a small coin, has sensors that curve like the retina of the eye. In fact, the device is called eyeball camera. Because the sensors are curved, and because the curvature can change synchronously with the curvature of the lens, it has excellent zoom capabilities. Unlike multi-lens systems with similar capabilities, the eyeball camera has a single fluid-filled lens. Rogers' work is published this week in the journal, Proceedings of the National Academy of Sciences.

Rogers is one of the pioneers in flexible electronics. He currently serves as the director of Nanoscale Science and Engineering Center on nanomanufacturing, funded by the US National Science Foundation. His technique is to use silicon itself, rather than organic materials, in his devices.

Rogers makes tiny pieces of silicon connected by coiled wires, and is deposited on plastic sheets using standard manufacturing techniques. When the materials stretch, the wires stretch too. Performance of the device does not deteriorate even when the material is stretched 75 per cent.

Considering the business potential of the research, Rogers has set up a company called MC10, and it has concluded an agreement with sportswear manufacturer Reebok to incorporate electronics into its shoes. An electronic-implanted shoe can monitor a runner's performance, among other things. It is the start of a new age of wearable electronics.

Bacterial Invention
When you have a serious problem, and none of your solutions is working, it pays to take a look at how nature would have solved the problem. This is why engineers are turning to biology to solve some of their most intractable problems. Some students from the Chinese University of Hong Kong recently turned to the bacterium Escherichia coli (E. Coli) when faced with the problem of large data storage. The bacteria obliged, paving the way for a technology to store data at extra-high densities. Scientists and engineers have been looking for a while at ways of using bacteria for data storage. A bacterium is tiny, and its components are tinier — so tiny that, theoretically, one gram of bacteria can store information worth 900 terra-bytes (that's space enough to store about a million movies!).

The information can also last for thousands of years (the best of today's storage media can manage at best 100 years). In practice, it is not so straightforward as it sounds. One has to find a way of writing the information, another way of keeping it safe from intruders and retrieving this information when necessary. Now scientists are developing methods for these.

In 2007, researchers at Japan's Keio University developed a method to store 100 bits of data within an artificial DNA. They used the method to code the equation E = MC2 within a bacteria found in the soil. Now the Chinese team has made a major advance: a method to compress, split and distribute data evenly between bacterial cells. They have a method to encode the data as well as one to locate it. They also use an altered form of the original bacterium that cannot exist outside the synthetic medium. The work is in early stages, and could take years before being applied.

(This story was published in Businessworld Issue Dated 07-02-2011)