General Description
The Colorimetric Retroreflecting Indicator Tags for Identification of Chemical Agents at Locations (CRITICAL) system consists of indicator badges and loose taggants for monitoring for CWA releases in the field. The CRITICAL indicator badges can be placed at strategic locations at DOD or industrial facilities and continuously monitored with standard networked CMOS cameras or by facility personnel at a long range. Further, when dispersed uniformly over an open area, CRITICAL taggants can be monitored to indicate and track CWA releases real-time. The taggants will work for a long duration in a range of environments, with the ability to be tailored to rainy, snowy, or dusty locations if needed. Readout of the badges and taggants will be simple enough for facility personnel with minimal training, and will require standard cameras and light sources to minimize infrastructure costs. The fabrication protocols scale up to mass-production, resulting in low cost for large facilities.
Technical Description
Colorimetric dyes on retroreflective microstructures and cheaply mass-fabricated retroreflector elements are the key technologies of the CRITICAL system. The dyes darken in the presence of various CWA's and TIC's. The resulting contrast on the retoreflector faces causes a sharp decrease in the returned signal from a broadband light source. The retroreflectors provide narrow reflected beam divergence, with correspondingly long detection range and the ability to operate covertly, and are easily mass-fabricated to cover large areas of installations or produce large quantities of indicator badges.
Evaluation Criteria
THROUGHPUT:
- 2 minutes or less for detection
- Multiple samples, multiple tests/sample per run
- System is continuous and provides real time analysis with no defined tests/samples
- The system could easily be adapted into a fully automated system
- Device or system is designed for a single use
- 0-1 solutions, buffer, eluents, and/or reagents
- 1 component
- Less than 5 minutes is required for set-up
- 1-2 steps are required for detection
LOGISTICS:
- Very brief (minutes-hours) training and minimal technical skills
- Approximately the size of a carry-on luggage suitcase
- Less than 1 kg
- Wireless and wired connections are available
- There is no electrical requirement
OPERATIONS:
- Can be used from -21°C to 41°C
- Components must be stored at room temperature (27°C)
- Performance is not influenced by relative humidity
- Greater than 3 years shelf life
- Results can be viewed in real-time
- The system could be adapted to a fully autonomous system with some effort
DETECTION:
- Less than 50 µL
- Good specificity. System has a consistently low level of false alarms (2-5%)
- >1x10-3 mg/m3
- 1 ppm-100 ppm
- Possible system could identify aerosolized chemical agent
- Possible system could identify liquid chemical agent