1. RFID Biosensors for the Detection of IEDs at 400 m Stand-off Distance
Dr. William D. Hunt
School of Electrical and Computer Engineering
Georgia Institute of Technology
Atlanta, GA
and
Dr. Peter J. Edmonson
P.J. Edmonson Ltd.
Hamilton, Ontario

2. Outline Team background Technology background Current RFID/Biosensor
Current 2D and 3D Algorithms
Myths and Truths
Proposed IED Detection Solution
Proposed RFID/Biosensor

3. Team Background (Hunt)
Research Focus: Microelectronic Acoustic devices and their application to molecular recognition in liquid and vapor phase
Jointly appointed at Emory University Medical School and Georgia Tech
25 years experience with acoustic wave devices.
6 years experience with biosensors
Fully equipped R&D lab for device design, fabrication and testing
70 publications in refereed journals and conference publications
10 patents (provisional and full)

4. Team Background (Edmonson)
33 years experience with acoustic wave devices.
> 40 Patents granted and several pending in radio, acoustic wave devices, RFID and Biosensors.
First RF engineer (1994) at Research in Motion, co-developed the Blackberry.
Part owner of RF/electronics design and manufacturing facilities (Toronto/Atlanta).

5. Experimental Setup For Lab Experiments Conducted to Date
Target: C-4 (RDX), TNT
Ref.
Anti-RDX
Anti-TNT
Emission
Sensor array
Flowcell
Intake
Sensor 1: reference
Sensor 2: anti-RDX
Sensor 3: anti-TNT
5um filter inserted before the
inlet to ensure no particle uptake

6. Technology Background
Successful detection of low-vapor pressure substances i.e. TNT, RDX, PETN, AN (Ammonium Nitrate) and Cocaine using acoustic wave biosensors.
Able to discriminate against close chemical analogs such as musk oil.
Current longevity of antibodies ≈ 2 weeks

7. Technology Background (2)
Development of 2D and 3D detection algorithms.
Presently involved in aptamer, peptide, antibody and plasma-deposited hydrogels research.
Currently developing an RFID/Biosensor.

8. Technology Background (3) RFID/Biosensor
An interrogation unit transmits an RF signal to an RFID/Biosensor.
RFID/Biosensor returns a modified signal indicative of cumulative binding events.
A 2.45 GHz RFID/Biosensor fabricated on quartz.

9. Technology Background (4) Algorithm Development
2 selected antibodies
Detection with a 2D Map
Only 10 samples required.

10. Technology Background (5) Algorithm Development
3 selected antibodies
Detection with a 3D Map
Only 10 samples required.

11. Myths and Truths
Myth: Antibodies must be designed for a specific substance.
Truth: No, within analogous groups such as explosives similar molecule binding due to the promiscuity of the antibody can take place.

12. Vapor Pressures for selected low vapor pressure chemicals
Myths and Truths (2)
Myth: Explosives have too low a vapor pressure to ever be detected directly so one must use particle collection prior to detection
Truth: We have detected cocaine, RDX and TNT in the vapor phase from dry samples.
10-9 Torr Torr 10-7 Torr Torr Torr
RDX PETN Cocaine TNT
Vapor Pressures for selected low vapor pressure chemicals

13. Our Proposed IED Detection Solution
During a period of hours or days prior to an event, scatter various RFID/Biosensors on or around intended routes or areas.
During event, interrogate RFID/Biosensors.
Sub-second explosive detection capability.

14. Proposed RFID/Biosensor (2)
Robust enough to be deployed via aircraft, vehicles or individuals.
Sample the surrounding environment.
Biolayer longevity of 1 – 2 weeks
Can be interrogated at anytime with built in anti-collision capability.
Able to return modified interrogation signal in microseconds.

15. Proposed RFID/Biosensor (3)
Stable, each biosensor has a built in reference.
Low cost, no silicon electronics on chip, single metal layer plus microlitres of biosolution.
Able to achieve reasonable shelf life.
Able to operate in various climates
Disables itself after termination of the biolayer.

16. Conclusions
Have detected various explosive substances with acoustic wave biosensors.
Have developed specific antibody techniques for 2D and 3D mapping algorithms of explosives and interferes.
Have begun experiments on a 2.45 GHz RFID/Biosensor.