August R&D Round UpAugust 6, 2010 By: Melanie Martella, Sensors
This month's collection of recent R&D news stories includes an implantable glucose sensor, sensors for lightning research, and an advanced system to monitor a ship's lubrication.
Under My Skin
In a big step toward better diabetes management, David Gough and Lucas Kumosa1 from the University of Calfornia San Diego Dept. of Bioengineering and Timothy Routh, Joe Lin, and Joseph Lucisano from GlySens Inc., have developed an implantable glucose sensor. In the paper "Function of an Implanted Tissue Glucose Sensor for More than 1 Year in Animals", published in the July 2010 issue of Science Translational Medicine, the researchers describe the sensor and its integrated wireless telemetry system.
Implanted into the subcutaneous tissues of two pigs, the device operated continuously for 222 and 500 days, respectively. The glucose sensor itself couples an electrochemical oxygen sensor with a cross-linked polymer gel containing the enzymes glucose oxidase and catalase. When glucose and oxygen diffuse into the gel, the enzymes catalyze the conversion of glucose to gluconic acid. The oxygen not used up in the reaction is detected and measured by the oxygen sensor and this reading is compared to a reference oxygen sensor that lacks the enzymes in polymer gel; the difference between the two oxygen concentrations correlates to the glucose concentration. The wireless telemetry system (contained within the device), then transmits the readings every 2 minutes to an external receiver for decoding an recording. (Read the whole article, because it is fascinating.)
Shining a Light on Lightning
This next story is incredibly apt, since as I write this there's a nice, loud thunderstorm going on outside. Anyway, in an ongoing attempt to learn more about how lightning correlates to strengthening hurricanes—whether lightning signifies a strengthening or lessening storm, for instance—researchers from NASA are planning to send the Lightning Instrument Package (LIP) up in a remotely piloted plane flying over the Gulf of Mexico and Atlantic Ocean during the hurricane-rich months of August and September. The LIP itself combines electric field mills to measure the amount of lightning produced and a conductivity probe to measure how easily the electricity can flow through the storm and the project has been around for 15 years. The latest advance, however, comes in the ability to send the instrument up in a plane that can remain aloft for 30 hours vs. the more typical 10 to 15 minutes that have been possible up to now. This should enable the researchers to gain a far clearer picture of the lightning characteristics of a storm as it develops and changes over time. If the data allows them to identify a correlation between lightning amount and hurricane strength, it will add another tool for meteorologists. (You can learn more about the project courtesy of the PhysOrg.com article, "NASA Lightning Research Happens in a Flash").
Monitoring Ship Lubrication
Researchers from the University of Sutherland's Institute for Automotive and Manufacturing Advanced Practice have developed a sensor-based processing unit and associated software to provide continuous monitoring of lubricating fluid used onboard ships. Named the Posseidon system, the sensor unit is attached to the ship's engine and monitors viscosity, water-in-oil, base number, impurities, and oil degradation and the associated software takes the sensor readings and then alerts the crew if there's a problem on the horizon. The goal is to give an early warning of potential problems, allowing the crew to take preventative measures or perform needed maintenance before the ship actually reaches the point of breaking down. The research is led by Dr. David Baglee and Dr. Mike Knowles.
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