When GPS fails, this speck of an electronic device could step in

Jul 11, 2013
This tiny "timing inertial measurement unit" could take over when GPS is unavailable. Credit: Becky Peterson

(Phys.org) —In a pellet of glass the size of an apple seed, University of Michigan engineering researchers have packed seven devices that together could potentially provide navigation in the absence of the satellite-based Global Positioning System (GPS.)

Space-based GPS – convenient for civilians and essential for the military – is far from fail-proof. It doesn't work indoors, near tall buildings or in heavy , and it's relatively easy to jam, researchers say.

"In some cases, there is no good solution for that yet," said Khalil Najafi, the Schlumberger Professor of Engineering and chair of electrical and computer engineering. "That's one of the reasons there's interest in developing this technology."

So-called "timing and inertial measurement units" similar to this new one are used nowadays as in cell phones, game controllers and , but the performance of these silicon sensors isn't good enough for navigation, positioning and guidance across larger distances or long times. Inertial sensors have been used to navigate ships and aircraft since long before GPS. Those still in use today in these vehicles are much larger.

"In the smallest commercial inertial systems, the volume is about the size of an apple, and most are larger – about the volume of four apples," Najafi said. "The volume of our device is less than an apple seed. The main breakthrough is that the technology we developed is hopefully going to allow us to build very high performing devices in extremely small sizes."

At 13 cubic millimeters, the package contains a highly-precise and six sensors that detect movement in six different axes.

To make their advanced inertial measurement unit, Najafi and his research group developed special that allows them to stack and bond the seven different devices in layers. And to make their unit more robust, they built it out of fused silica – a high quality glass – rather than silicon, which is commonly used for these types of devices.

Timing and inertial measurement units track a path by measuring speed, time, direction and distance from a starting point. "In order to measure position, you need to know where you are and then how far you've moved in so much time and in what direction," Najafi said.

GPS receivers, on the other hand, calculate location based on their movement in relation to a network of satellites. The satellites continuously ping the receiver. Najafi envisions that the two approaches could be combined so navigation systems would have a backup component and seamless operation both outdoors and indoors. But that, he believes, is at least five years away.

Other researchers who contributed to the work include: post-doctoral research fellow Zongliang Cao; graduate student Yi Yuan; assistant research scientist Becky Peterson; and visiting assistant research scientist Guohong He, all in the department of electrical engineering and computer science. Najafi and his colleagues presented a paper on the device, "Fabrication of Multi-Layer Vertically Stacked Fused Silica Microsystems" on June 18 at the 17th International Conference on Solid-State Sensors, Actuator and Microsystems Conference (Transducers '2013) in Barcelona, Spain. Mina Rais-Zadeh, assistant professor of electrical and computer engineering, and her group developed the timing unit for this system. Najafi is also an Arthur F. Thurneau professor and a professor of biomedical engineering.

Explore further: New technique helps robotic vehicles find their way

More information: transducers-eurosensors2013.org/

Related Stories

New technique helps robotic vehicles find their way

May 14, 2013

(Phys.org) —A Wayne State University researcher understands that the three most important things about real estate also apply to small ground robotic vehicles: location, location, location.

Recommended for you

Large streams of data warn cars, banks and oil drillers

Apr 16, 2014

Better warning systems that alert motorists to a collision, make banks aware of the risk of losses on bad customers, and tell oil companies about potential problems with new drilling. This is the aim of AMIDST, the EU project ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

bearly
1 / 5 (1) Jul 11, 2013
How soon can I buy one ?
Myno
not rated yet Jul 12, 2013
What is its performance compared to the devices found in smart phones?

More news stories

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

Deadly human pathogen Cryptococcus fully sequenced

Within each strand of DNA lies the blueprint for building an organism, along with the keys to its evolution and survival. These genetic instructions can give valuable insight into why pathogens like Cryptococcus ne ...