Your World On A Pen Tip

It’s one of the truisms of our Tech Age that computing capacities are rising while processor sizes are falling. That hasn’t been lost on University of Michigan researchers who have developed a computer which fits on the tip of a pen.

This is a special-purpose computer designed for one specific task, notes Dick Eastman, who blogs on genealogy, computers and technology.

“It does not contain a keyboard or a video screen,” he writes. “All output is performed by a wireless radio with an antenna that can transmit data to an external reader.”

The millimeter-scale computing system can hold up to a week's worth of data when implanted in something as small as a human eye.

The computer, called the Phoenix chip, is just over one cubic millimeter in size and was designed to monitor eye pressure in glaucoma patients.

“This is the first true millimeter-scale complete computing system,” says Dennis Sylvester, a professor at the school and one of the researchers on the project.

Within the computer is an ultra low-power microprocessor, a pressure sensor, memory, a thin-film battery, a solar cell and a wireless radio, according to Eastman.

The micro computers and their wireless networks also could one day be used to track pollution, monitor structural integrity, perform surveillance, or make virtually any object smart and trackable, researchers say.

Not Any Chip

The Phoenix chip sips power. It has a power-gating architecture with an extreme sleep mode that wakes the computer up briefly every 15 minutes to take readings, and it uses an average of just 5.3 nanowatts each time it turns on, writes Lucas Mearian for computerworld.com.

The Phoenix chip has a photovoltaic charging system which requires 10 hours of indoor light or 1.5 hours of sunlight to fully charge the battery.

The chip's micro radio automatically tunes into whatever wireless frequency is available in order to download data to a reader. The data can then be used as part of an electronic medical record for treatment.

“Our work is unique in the sense that we're thinking about complete systems in which all the components are low-power and fit on the chip,” Sylvester says. “We can collect data, store it and transmit it. The applications for systems of this size are endless.”

What Lies Beyond

Researchers in this field point to Bell's Law, which states that there's a new class of smaller, cheaper computers about every decade. With each new class, the volume shrinks by two orders of magnitude and the number of systems per person increases.

The law, named for computer engineer and manager Gordon Bell (above right) has held true from the mainframes of the 1960s through the personal computers of the 1980s, the notebooks of the 1990s and the today's smartphones, they say.

“When you get smaller-than-handheld devices, you turn to these monitoring devices, says David Blaauw, another professor and Phoenix chip researcher at the University of Michigan.

“The next big challenge is to achieve millimeter-scale systems, which have a host of new applications for monitoring our bodies, our environment and our buildings,” Blaauw says.

One Eastman blog reader asks: “How small can a computer be and still be useful? How about cell phones with quad-core processors? They'll be here by Christmas.”

With smartphones becoming like electronic wallets, the blog reader is probably right. It's a small world after all ... and getting smaller all the time!

Ken Cocuzzo