Overview of the TAC-BIO sensor

In light of the current state of detection technologies designed to meet the current threat from biological agents, the need for a low-cost and lightweight sensor is clear. Such a sensor based on optical detection, with real time responses and no consumables, is possible. Devices arising from the Defense Advanced Research Projects Agency's (DARPA) Semiconductor UV Optical Sources (SUVOS) are the enabling technology. These sources are capable of emitting UV wavelengths known to excite fluorescence from biological agent particles while costing a few dollars apiece and consuming low power. These devices are exploited in the TAC-Bio Sensor. A unique optical design is used to collect the usable portion of the LED emission and focus it into the probing region of the sensor. To compensate for the low UV power density relative to UV lasers, the TAC-Bio utilizes a unique opposed flow configuration to increase the interaction between particles and the UV beam. The current TAC-Bio sensor testbed is capable of detecting fluorescence Bacillus globigii (BG, an anthrax simulant) spore agglomerates down to 5 microns in diameter. Ongoing work is focusing on increasing signal to noise so that smaller particles, possibly single spores, can be detected, as well as on including additional data channels, such as light scattering, to increase selectivity of the sensor.