Researchers at the Massachusetts Institute of Technology (MIT) and Texas Instruments (TI) have unveiled a new chip design for portable electronics that they claim can be up to ten times more energy-efficient than present technology. The design could lead to cell phones, implantable medical devices and sensors that last far longer when running from a battery. The work was conducted at the MIT Microsystems Technology Laboratories, directed by Professor Anantha Chandrakasan.
The key to the improvement in energy efficiency was to find ways of making the circuits on the chip work at a voltage level much lower than usual. While most current chips operate at around 1V, the new design works at just 0.3V. Reducing the operating voltage, however, is not as simple as it might sound, because existing microchips have been optimized for many years to operate at the higher standard voltage level. "Memory and logic circuits have to be redesigned to operate at very low power supply voltages," Chandrakasan stated.
One key to the new design, according to Chandrakasan, was to build a dc to dc converter – which reduces the voltage to the lower level – right onto the same chip, which is more efficient than having the converter as a separate component. The redesigned memory and logic, along with the dc to dc converter, are all integrated to realize a complete system-on-a-chip solution.
One of the biggest problems the team had to overcome was the variability that occurs in typical chip manufacturing. At lower voltage levels, variations and imperfections in the silicon chip become more problematic. "Designing the chip to minimize its vulnerability to such variations is a big part of our strategy," Chandrakasan stated.
So far the new chip is a proof of concept. Commercial applications could become available "in five years in a number of exciting areas," according to Chandrakasan. For example, portable and implantable medical devices, portable communications devices and networking devices could be based on such chips, and thus have greatly increased operating times. There may also be a variety of military applications in the production of tiny, self-contained sensor networks that could be dispersed in a battlefield.
In some applications, such as implantable medical devices, the goal is to make the power requirements so low that they could be powered by "ambient energy," – using the body’s own heat or movement to provide all the needed power. In addition, the technology could be suitable for body area networks or wirelessly-enabled body sensor networks.
"Together, TI and MIT have pioneered many advances that lower power in electronic devices, and we are proud to be part of this revolutionary, world- class university research," said Dr. Dennis Buss, Chief Scientist at Texas Instruments. "These design techniques show great potential for TI future low power IC products and applications including wireless terminals, RFID, battery-operated instrumentation, sensor networks, medical electronics and many others."
The research was funded in part by a grant from the U.S. Defense Advanced Research Projects Agency.