Issue No. 07 - July (2006 vol. 39)
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/MC.2006.241
Researchers Develop Transparent Chip
Oregon State University researchers have developed a transparent integrated circuit. According to Carl D. Howe, an analyst with Blackfriars Consulting, this technology could eventually allow electronics to be integrated into transparent objects such as car windshields, bottles, and glasses. This could enable new applications such as next-generation displays and car windshields with pop-up alerts.
"Oregon State's test chip contains a five-stage ring oscillator, a simple IC," said professor John Wager. The key challenges were discovering how to process and integrate materials that would yield transparent IC elements, including the substrate, contacts, insulators, and transistor channels.
To accomplish this, the researchers made the substrate of glass, the transistor channels of indium gallium oxide, the contacts of indium tin oxide, and the insulators of silicon dioxide. All are transparent and can be produced via conventional photolithography. For transistor channels, the researchers are experimenting with a new class of transparent binary oxide materials that are robust and amorphous and thus pliable, stable, and easy to work with.
Wager said his team's work indicates transparent ICs eventually could achieve speeds of a few megahertz, not as fast as advanced microprocessors but good enough for many purposes.
The US National Science Foundation, the US Army Research Office, and Hewlett-Packard helped fund the work. HP, which plans to commercialize the new technology, will use the approach to build, for example, arrays of antennas and sensors that would be less unsightly because they would be transparent, noted Mike Brown, a technology business-development manager with the company.
Transparent electronics might also enable applications such as instruments that show their readings on airplane cockpit windows or displays—like those for flight departure and arrival times—in public facilities. They could also prove useful in cell phones, televisions, and game consoles.
The technology might even enable more efficient solar cells, with the ICs adding functionality and the transparency enabling the devices to gather more sunlight to convert into energy.
"There is still so much basic research to be done before bringing the products and applications to market," noted Brown. For example, Wager explained, researchers must identify the best materials to use and determine how to build transparent ICs that are inexpensive and power efficient and that can be manufactured in large volumes. He said transparent ICs might become widely used in about five years if proponents can identify a killer application.
Because of the research that still must be done, Howe predicted the ICs won't become popular until perhaps 2015.
Building Batteries with Biology
A team of scientists has engineered a biological virus so that it will build nanowires that could be part of the lithium ion batteries used in small devices.
The team, led by Massachusetts Institute of Technology researchers, worked with the M13 virus. M13—a bacteriophage, a virus that infects bacteria—is about 880 nanometers long by 6 nanometers wide. This thin structure, which is different than most viruses' more spherical shape, is ideal for forming nanowires, noted MIT professor Angela M. Belcher.
Researchers raised the viruses inside host bacteria kept in a fluid-filled flask in an incubator. They genetically modified the M13 so that its outer protein layer would contain an additional peptide that could grow cobalt oxide. After separating the grown viruses from the host bacteria, they added cobalt salt, which the M13 used to build cobalt oxide.
In solution at high concentrations, the viruses form liquid crystalline structures of uniform size that grow in orderly layers and self-assemble into nanowires, Belcher noted. When grown on a polymer electrolytic surface, to which it is attracted electrostatically, the wiring forms a battery's positive electrode.
The researchers added another peptide to the M13 that would help absorb gold, which improved the system's electrical conduction and structural stability. Adding gold also increased the structures' energy density, allowing them to store the most energy in the least space, thereby yielding small, light batteries.
The new approach could be used for almost any type of battery, but the team focused on lithium ion batteries because they found them most interesting, Belcher noted.
Because the technique organizes wiring on surfaces that could be in almost any shape, it could yield batteries in many different forms. This would let manufacturers design batteries around a given product, rather than vice versa, as is frequently the case today, Belcher said.
In addition, she noted, the technique uses no organic solvents and is thus environmentally friendly. And because the process can take place at room temperature, it is easier and less expensive to use than approaches that require very hot or cold conditions.
The team expects to have a working prototype of a full, self-assembling battery in about two years.
New Tool Enables Hands-Free Coding
A Canadian organization has designed a voice-recognition application that lets programmers write code by simply speaking.
The National Research Council of Canada's open source, freely downloadable VoiceCode tool lets users dictate code, translating what they say into proper programming.
For example, to write for spch WinInd in range(maxWnds): <CURSOR HERE>—Python coding that would command an application to loop through a GUI's list of speech-enabled windows—a VoiceCode user need only say, "For each speech window index in range of max windows do the following."
The tool doesn't work with natural language but does let users express coding in a range of ways, letting them choose the form they prefer, explained Alain Désilets, research officer at the NRC's Institute for Information Technology.
Standard off-the-shelf speech-recognition products don't work well for programming because they can't always translate symbols accurately or properly construct the syntax. Moreover, said Désilets, off-the-shelf software requires programmers to explicitly utter each of the many punctuation marks that computer code contains, which is time-consuming and "cognitively demanding."
NRC researchers overcame this, he noted, by giving VoiceCode knowledge of how programmers express themselves when coding in a specific language and how to translate those utterances properly. VoiceCode translates speech into code based on the information the application has about a given language, the context—such as whether a certain type of entry, like a class name, belongs at a certain place—and the user's preferences.
"Hopefully, this will eventually reach a point at which programmers can dictate code by truly saying anything that comes to them naturally," he said.
VoiceCode works for programming in Python, C, or C++ and is being adapted for Java and PHP. Programmers could make VoiceCode support other languages. However, noted Désilets, "This is about a two-week, full-time job for one person."
The NRC—along with researchers at Harvard University and the University of California, Santa Cruz—designed the application to assist programmers with repetitive strain injury. Some experts attribute RSI to using a keyboard or mouse for long periods of time and say it includes conditions such as chronic nerve inflammation, tendonitis, and carpal tunnel syndrome.
"RSI is a big problem that leads to huge societal costs because of missed work, disability, et cetera," noted Pedro K. Beredjiklian, MD, assistant professor of orthopedic surgery at the University of Pennsylvania's School of Medicine.
Orthopedic surgeons disagree about RSI, its causes, and its treatment. Nonetheless, said Leon Benson, MD, orthopedic surgeon at the Illinois Bone and Joint Institute, "Voice recognition software may be helpful by reducing the need to type all day long, which, like any prolonged activity, can cause tendon inflammation and muscle aches and can also aggravate preexisting condition like arthritis or carpal tunnel syndrome."
VoiceCode might also prove useful for people who cannot type because of other disabilities, such as paralysis.
The tool is not as fast as using a mouse and keyboard, so it is not necessarily suitable for programmers who have no trouble typing, noted Désilets, who says he has suffered from RSI.
The project's Web site ( http://voicecode.iit.nrc.ca/VoiceCode/public/ywiki.cgi) provides help with and information about the software.
Désilets' said the NRC has no plans to commercialize VoiceCode.
News Briefs written by Linda Dailey Paulson, a freelance technology writer based in Ventura, California. Contact her at email@example.com.