SBIR-STTR Award

After initially being located by a separate landmine detector system, such as a metal detector or ground penetrating radar, a buried object can be analyzed by a fast response chemical-sensing detector to confirm or reject the presence of explosives with a high degree of a confidence. The lack of such a desirable confirmatory device is due to the absence of a portable, fast response chemical sensor capable of detecting molecules of energetic materials at pg/cm2 or ng/cm3 (in soil) concentrations. Implant Sciences Corporation has developed an advanced sensor capable of detecting vapors of the major explosives TNT, RDX, PETN, etc. within 0.2-3 seconds. The portable sensor has a sensitivity enough to detect the buried mine, and even trace its location from a moderate distance, if the vapors can be delivered to the sensor. Explosives material particle/vapor extraction from the media surrounding the landmine, transportation to the chemical detector, and injection into the sampling port will be accomplished using a cyclone system. In Phase I an explosives vapor/particle sampling module will be developed, interfaced with a chemical vapor detector, and prepared for field testing. In Phase II the chemical detector prototype will become a component of a Landmine Multi-Detector Device Confirmation of the detection of explosives is essential due to the high rate of false positives from most devices now in use. Land mines are a special application in that remote sensing and confirmation are desirable. Existing portable chemical sensors are not capable of remote sensing and have limited sensitivity. The proposed cyclone vapor/particle sampling module accomplishes these goals and can create a chemical confirmatory system for a landmine with significant reduction in the false-positive response

In Phase I, Implant Sciences Corp. (ISC) constructed an early prototype cyclone vapor sampling system with an integrated surface heater to extract explosives and ERC vapors from soil samples and to deliver the extracted vapors to a chemical detector. The physical design of the cyclone unit and its operating parameters were highly optimized. Phase I results are very promising. In its current state, the cyclone module excludes particulates from the collected sample vapors, which is helpful in minimizing contamination of the detector, and can operate in crosswinds of up to 4 mph without significant loss of sample vapors to the ambient air. With the prototype sampling system interfaced to ISC's ultra-sensitive Laser IMS system, the ability to detect ppm ppb concentrations of TNT and RDX in two types of soil was demonstrated, with a response time significantly less than one second. By the end of Phase I, a prototype device will be available for field testing. In Phase II, the design of the cyclone unit and the sample heater will be further optimized for a portable unit, and all components will be combined and modified as necessary to work as a complete system and to minimize size, weight and power consumption.

Benefits:
Implant Sciences Corporation has developed an explosives detection system which uses a cyclone vapor sampling module to extract trace explosives and ERC vapors from the environment and to direct the vapors into an ultra-sensitive Laser IMS system. This technology can be used to create a rapid-response chemical detector system to confirm or disprove the presence of buried land mines with a false-positive response rate substantially lower than those of currently employed portable explosives detectors. Since the detection of buried land mines is more difficult than many explosives detection tasks, the technologies developed in this effort could easily be adapted for use in general explosives detection, for which there is a large and growing application base in the strengthening of homeland security and in improving the security of, e.g., the airline, shipping, power and chemical industries.

Keywords:
mine detection, trace explosives detection, trace explosives-related chemical detection, vapor sampling, particle sampling, Ion Mobility Spectrometry, Laser Resonance Enhanced Multi-Photon Ionization