When you can't be there: Cheap, solar-powered sensors to monitor remote Alaska infrastructure

Solar-powered sensors already exist, but are expensive and lack the capabilities of a new monitoring device that electrical engineering professor John Lund is now designing.

His wireless device would likely be used along remote roads in Alaska, keeping an eye on culverts, telephone poles, bridges and other essential infrastructure.  The sensor could be programmed to measure a feature like light, lean or orientation – some indicator of change, and constantly transmit that data whenever the device has the solar power to do so – which would be about every 30 seconds.

Circuit board for solar-powered sensor

Lund won an INNOVATE award in December 2011 to design and create the sensors over the next six months. He intends to pursue a patent and publish in a peer-reviewed journal.

The cool part of Lund’s design is that – because these devices have FRAM, or special memory qualities – each sensoring device receives and stores all data from every other device in its same network; if one fails, every other monitor in the system contains all the data for the entire network.

Imagine an Alaska state vehicle (State Troopers or DOT trucks) or even commercial truckers traveling remote main roads across the state. A sensor on that vehicle would be capable of scooping up vast amounts of data as it travels along. Transmitting devices attached to telephone poles, for example, would be capable of sending information across at least one kilometer.

Pass over a bridge, and the sensor on the bridge could report even a minute change in the bridge’s orientation – a deviation that might not be even noticeable to the traveler.

Move along a highway and gather data from every side road you pass. 

Further, if one node in the system is connected to a power grid, it can report the entire network’s data over a cellular network.  It would be possible to sit in a warm office in Fairbanks, and monitor infrastructure hundreds of miles away.

Imagine that this device costs no more than $10, and because it doesn’t have any batteries, lasts more than 50 years. Imagine that it gets installed at the point of construction – so no expensive retrofits are required.

Telephone poles can cost $4,000 a piece, a culvert can be $300.  A $10 monitoring device for expensive infrastructure security makes sense. Lund’s devices are aimed at long-term monitoring, capturing small changes that signal the need for more attention before something significant -- like a bridge failure -- occurs.

But what happens in winter, when light disappears and snow covers everything? If there is no snow cover, ambient light will be enough to power sensors. They’ll just report a little more slowly -- like every 90 seconds instead of every half-minute.  When covered by snow, they’ll go silent until light returns.

Their battery-free quality means temperature is no factor in their function. According to Lund, electronics only function to about minus 40 degrees F; batteries only to about minus 10. That eliminates a lot of Alaska’s geography, a flaw that his devices can overcome. 

Lund is using mostly off-the-shelf hardware to create the device. Programming its function is his added value.

“Until now, we haven’t put high tech and low tech together like this,” he said, “High tech was much too expensive. Now it’s possible.”
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John Lund

John Lund grew up in Anchorage and graduated from East High School. He earned a B.A. in computer engineering from Washington State University in Pullman, WA, and his master’s and doctorate in electrical engineering from the University of Washington in Seattle.

He joined the UAA School of Engineering faculty in 2009. His research emphasis is micro/nano-scale fabrication, analog/digital filter design, control systems, automation, microscopy, computer vision, system integration, biosensors, surface/molecular engineering.