Portland, Ore. Defense contractor Custom Electronics has partnered with Sandia National Laboratories to develop a commercial sensor that will warn a driver the car's battery will fail a few days down the road.
Custom Electronics (Oneonta, N.Y.) decided to join Sandia's new Mission Centric Venturing program after seeing a benchtop demonstration of its sensor, which will make a light blink on a car's dashboard. The warning system was developed by Sandia researcher Jonathan Weiss.
"Since our mission here now includes economic competitiveness, I have adapted optic sensors for low-cost solutions to commercial sensor problems," said Weiss.
The car battery in Weiss' scheme requires only a hollow glass tube filled with sulfuric acid, an LED and a photodetector. "If the battery is in good shape, then the index of refraction for the liquid in the sensor tube will be the same as the battery's fluid. But before a battery fails, its fluid changes its index of refraction, which we can then sense," said Weiss.
Normally, the LED shines light down the 5-cm-long tube and out into the battery, so that very little light gets back to the sensor sitting next to the LED. However, when the sulfuric acid in the battery starts to become more dilute, its changing index of refraction causes it to refract some of the light back into the 1.5-mm-diameter tube. A mirror at the bottom of the tube reflects this extra light backward so that it can register on the photodetector.
Weiss holds 13 patents for this and 12 other optically based technologies configured as low-cost sensors, many of which use fiber optics.
The patents are still pending for the maiden-voyage partnership with Custom Electronics, but Weiss was allowed to reveal that they solve a longstanding problem in the oil refinery industry: Oil and water don't mix.
Automated pumping systems need to be able to draw oil from the top of containers, but stop pumping before they get down to the water that, in nature, comes inevitably mixed with the oil. Weiss' better, cheaper sensor hangs two fiber-optic cables in the container, one to emit and one to sense. This enables the pump controller to automatically stop pumping before hitting the water.
Sandia National Laboratories is part of the U.S. Department of Energy.