Chips that really get under your skin
By Tom Krazit
Staff Writer, CNET News.com
Published: February 8, 2006, 6:15 PM PST
SAN FRANCISCO–Without the white headphones, how will anyone know you’re listening to an iPod?
Researchers at the Korea Advanced Institute of Science and Technology (KAIST) weren’t concerned with such weighty questions when they developed a chip that allows you to listen to an iPod using your forearm as the transmission wire for the audio signals. The chip was detailed in one of several presentations during a session called “Silicon in Biology” at the International Solid State Circuits Conference (ISSCC) here Thursday.
Low power consumption was a common design thread throughout the several different chips presented by university researchers. The need to reduce power consumption of chips has become a mantra for the PC and server processor industry, but low power consumption takes on a new meaning when referring to chips that will be used inside the human body or on skin.
KAIST has built a prototype chip it thinks solves some of the problems encountered in setting up personal-area networks that take advantage of the body’s ability to conduct electricity. Computer scientists have long envisioned connecting the numerous personal electronic devices the average technology fan carries around each day, but wiring those devices together is impractical, and Bluetooth connections are prone to interference, said Seong-Jun Song, a professor at KAIST.
Other groups have explored ways of using the body itself as the networking cable, but early chips consumed too much power or used data rates that were too slow for effective communication, Song said. KAIST’s chip uses wideband signaling to reduce power consumption while boosting data rate. The chip sends low-power impulses across a wide swath of frequencies, rather than sending a high-power signal down a narrow frequency.
KAIST researchers modified an iPod nano and an earphone with its test chips for demonstration purposes. A user would need to keep a finger constantly pressed to a conductor on the iPod, which would send the audio signal through the arm to the earphone. The chips can produce data rates of up to 2 megabits per second while consuming less than 10 microwatts, Song said.
These chips are not something that will be included in one of Apple Computer CEO Steve Jobs’ Macworld keynotes anytime soon. The papers presented at ISSCC are generally research projects that are several steps away from becoming products.
Another paper presented during the session outlined a chip designed to monitor brain activity by sending its data wirelessly to monitors. The University of Utah has been working on chips that monitor neural impulses in quadriplegics in hopes of finding a way to build prosthetic limbs powered by brain waves. However, early testers of those chips had to have the chips implanted in their brains connected to external computers by wires, which is obviously uncomfortable.
Wireless transmitters for this type of brain measurement also had to be very sensitive to power consumption levels to avoid destroying brain tissue, said Reid Harrison, a professor at the university. Researchers believe they have come up with a low-power wireless chip by reducing the size of the data captured by the chip, and allowing doctors to selectively choose what neural activity to monitor and when, he said.