Bio/Chem agent detection and decontamination

1. Bio/Chem agent detection and decontamination Kin P. Cheung Electrical & Computer Engineering

2. Up to 2000 liter in 20 minutes The most dangerous bioagent attack is in the form of aerosol An adult human inhales 10 – 100 liter per minute of air Infective doses of selected aerosol BW agents Anthrax 8000–10,000 spores ~5 spores/Liter Brucellosis 10–100 organisms ~0.01 /Liter Plague 3000 organisms ~1 /Liter Q fever 1–10 organisms ~0.001 /Liter Tularemia 10–50 organisms ~0.01 /Liter Smallpox 10–100 organisms ~0.01 /Liter Viral encephalitides 10–100 organisms ~0.01 /Liter Viral hemorrhagic fevers 1–10 organisms ~0.001 /Liter Botulinum toxin 0.07 µg/kg ~3ng /Liter Staph. enterotoxin B 0.02 ug/kg (lethal) ~1ng /Liter D. R. Walt, D. R. Franz, Analytical Chem. 72(23), 738A(2000).

3. Assume a particle 104 heavier than air molecule Average thermal velocity ~ 400cm/s The impingement rate to a 1cm2 area detecting surface is: Passive detector is out of the question. Sample concentration method that collect ~1000 liters of air in one minute is needed. Ultra compact detector is not a practical goal.

4. ~ 1 minute trigger time One batch of consumable per minute. Large number of detectors are assumed to be in a distributed network that requires minimum human intervention for extended period. For civilian protection, sufficient time must be budgeted for after alarm procedure: Detector that requires consumable is not practical. Immunoassay based technology is not attractive.

5. Optical detection has fundamental issues: The basic composition of all life form are the same. Very little difference between microbes How to tell the difference between naturally occurring and harmless aerosols from harmful one? High false alarm rate is worse than no alarm. The only region of spectrum that has the potential to distinguish one microbe from another is the millimeter wave. High-resolution THz spectroscopy is very promising. A unique, ultra high sensitivity, ultra broad band, ultra high resolution THz spectroscopy method is being developed for bio-aerosol detection here at Rutgers. The three ultras are of key important!

6. Bio/Chem agent decontamination using non-thermal, atmospheric pressure plasma Atmospheric pressure, non-thermal plasma is well known to have high potential for waste gas treatment and medical instrument sterilization. The main problem has been cost.

7. The promising potential of plasmas for decon was clearly identified during the U.S. Military’s Decon Front End Analysis (FEA) conducted in December 1998. This FEA forms the backbone of the Joint Services Decon Master Plan. Technologies were graded against 21 different criteria that were weighted by the military’s user community. Atmospheric-pressure plasma (APP) ranked high in most functional areas.

8. The problems are energy efficiency, logistics, size and cost. All atmospheric pressure plasma requires high voltage supply. Some requires high power RF. Some only operate in special carrier gas. Most requires cooling Most are not very reliable Most are bulky The ideal combination of high efficiency, operate in one air, running in low DC voltage, compact, long life and low cost does not exist. Practical implementation for home land defense is not yet possible. We are building a unique plasma source using the combination of MEMS and IC technology that will satisfy this ideal plasma source requirement.

9. plasma filter fan Emergency protection application: A compact forced air plasma source coupled with air filter can be used to create a positive pressure personal protection zone: A low cost, bio/chem emergency protection garment can be made.