May R&D Round UpMay 3, 2013 By: Melanie Martella, Sensors
This month's collection of clever and useful research and development stories includes a system to gather more and better data on how explosions affect soldiers and a continuous UV sensor.
Explosion Impact Monitoring
Blast injuries are the signature injury in our current conflicts. The people trying to protect the troops and the people trying to save them post-blast have, over the last ten years of practice, learned a very great deal. There's still a lot we don't know about what happens when a shock wave, and the compressed air in front of it, hits a human body and that is where the IBESS system comes in. Developed at the Georgia Tech Research Institute (GTRI) as part of the Department of Defense Information Analysis Center (IAC) program in response to the Army's Rapid Equipping Force request, the Integrated Blast Effect Sensor Suite (IBESS) is designed to collect data about the physical environment of the explosion during the event which can then be used to generate a clearer picture of exactly what happened. Rather than just measuring the magnitude of the blast experienced, they want to know how big the blast was and where it was coming from.
As explained in the news article, "Researchers Develop Sensor System to Assess the Effects of Explosions on Soldiers", the system has two parts; one carried by the soldier and another that's mounted in a vehicle. The system carried by the soldier incorporates a recorder connected to four pressure sensors, two of which are on straps that hang over the front of the soldier's shoulders and another two on the back. The recorder itself attaches to the body armor between the shoulder blades. By having the sensors oriented around the body, the system can record the directionality of the pressure waves experienced. It's also designed to remain in sleep mode until it's triggered to wake up and start collecting data.
The vehicle-mounted part of the system works to monitor and record the blast events experienced by the vehicle (additional inertial sensors installed on the vehicle frame and seats are used to collect data if the vehicle rolls over or experiences an explosion) and its passengers. It links to the system carried by the soldier in a rather nifty use of semi-passive RFID and Bluetooth. Time-tagged data from both the soldier's and vehicle's sensors are stored in a black box. It's an incredibly elegant and robust solution.
Continuous UV Monitoring
The clever, clever people at the Fraunhofer Institute for Applied Solid State Physics (IAF) in Freiburg, Germany, working with their colleagues at the Fraunhofer Institutes for Manufacturing Technology and Advanced Materials (IFAM), for Optronics, System Technologies and Image Exploitation (IOSB), for Silicon Technology (ISIT), and for Physical Measurement Techniques (IPM) have managed to create a UV sensor that isn't damaged by exposure to UV. By building the sensor using aluminum gallium nitride on a sapphire substrate, the sensor can withstand continuous exposure to UV without suffering damage, a behavior that has limited the use and utility of existing UV sensors. As the researchers explain in the article, "Continuous monitoring of UV exposure", their novel sensors can withstand high-intensity UV and while they could be used to take snapshot measurements of UV they could also be used for inline process monitoring.
In addition, the sensors can be tweaked to enable the monitoring of specific wavelength ranges by altering the ratio of materials in some of the gallium nitride layers. By defining a maximum wavelength threshold, the researchers can make the sensor detect all UV emitted at wavelengths below the threshold. Alternatively, by making sensors with two wavelength thresholds, the researchers can create sensors that are sensitive to a constrained portion of the spectrum, such as a sensor for UV-A (400–315 nm), one for UV-B (315–280 nm), and one for UV-C (280–100 nm).
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