Rice University
Rice Magazine| The Magazine of Rice University | No. 3 | 2009

Chip Off the Old School Slate

The image of rural schoolchildren in underdeveloped countries chalking their lessons on old-fashioned blackboard slates may soon change, thanks to an energy-stingy computer chip invented by Krishna Palem, Rice’s Ken and Audrey Kennedy Professor of Computer Science and Electrical and Computer Engineering.

Palem’s breakthrough chip, called PCMOS (for probabilistic complementary metal-oxide semiconductor), trades off precision in calculations for significant reductions in energy use. Prototype PCMOS chips were found to use 30 times less electricity while running seven times faster than today’s best technology. Although PCMOS runs on standard silicon, it breaks with current computing by abandoning the set of mathematical rules — called Boolean logic — that have thus far been used in all digital computers. PCMOS instead uses probabilistic logic, a new form of logic developed by Palem and his postdoctoral research associate, Lakshmi Chakrapani.

A key to using the technology is finding applications — like streaming video for cell phones or low-powered video displays — where error can be tolerated. The upshot could be cell phones that have to be recharged every few weeks rather than every few days. The chips will find their first real-world use in a solar-powered electronic slate, or I-slate, an electronic version of the slates used by many schoo lchildren in rural India. The I-slate’s developers are working with educational technologists from the International Institute of Information Technology, Hyderabad, in India, to develop a visually based mathematics curriculum that allows children to learn by doing, regardless of their culture, their native tongue, their grade level or whether they have a full-time teacher.

“We expect to begin testing prototypes of the curriculum and the I-slates next spring,” Palem said.
Inspired by microfinance, the I-slate’s innovators intend to use social entrepreneurism to create a self-sustaining economic model for the I-slate that both creates jobs in impoverished areas and ensures the I-slate’s continued success.