1) The document describes a MEMS device called the Rapid Pathogen Screener that was designed by a student to quickly detect bacteria in liquid samples for food and water safety testing. 2) Current testing methods take 24-48 hours and are expensive, but the Rapid Pathogen Screener uses dielectrophoresis to separate and concentrate bacteria within 30 minutes, making it faster and cheaper. 3) A prototype of the Rapid Pathogen Screener has been built that uses an electric field to trap E. coli bacteria and then antibodies and nanowire sensors to detect the bacteria, demonstrating the concept.

1. http://www.salon.com
From student project to marketplace:
Rapid Pathogen Screener
for Food Safety Testing
Monika Weber
Yale University
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2. Professor Hur Koser and Dr. Muhammet Uncuer
MEMS Design Class
Class Room
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Homework Assignment
Design a MEMS device with market potential
Memx.com

3. How to get started?
Hat is the problem we want to solve?
Class Room
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4. Food Safety Testing
Liquid products
Water Safety Monitoring
Drinking water
Recreational Water Safety
Health and Safety
Antibiotic resistance
Food Safety Monitoring
Problem:
outbreaks of bacterial infections
are hard to diagnose
http://www.salon.com
Fast Bacteria detection is important!
Outbreaks reoccur
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5. Current testing methods
long and expensive
Standard Plate Count
Culture samples and manual count of
aerobic bacteria
• Time: 24 - 48 hr
• Cost: ~$20 / test
• Set-up: Lab, incubator, labor
• Accuracy: More samples, longer
incubation time
PCR
• Enzymatic-based replication of DNA,
and readout of fluorescent signal
• Time: 2 - 3 hr
• Cost: ~ $50 / test
• Set-up: PCR machine, labor
• Accuracy: More samples, longer
incubation time
http://app.infoaa.7700.gnb.ca/gnb/Pub/EServices/ListServiceDetails.asp
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6. 6
Problem
We have a problem,
How to solve it?

7. Target specification:
• Miniaturized
• High accuracy
• Portable
• High sensitivity
• No culture growth
• Short detection time
• Low cost
• Easy in operation
Target Specification:
Less that 10 bacteria in 100ml of water detected faster than 30min
Rapid Pathogen Screener
Our solution
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8. 8
Solution
How to make the device?

9. Bacteria Separation
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10. Dielectrophoresis
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•Target sensitivity: 10 bacteria in 1cc animal blood sample
•Dielectrophoretic force confines bacteria within a defined
region of the channel
Size (R) and dielectric properties (ε) based
separation
Different species have different ε,
changing the permittivity of the fluid affects
separation

11. Bacteria Separation
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DEP force simulation
COMSOL multiphysics
Microchannel cross section
Dielectrophoretic
force on EColi

12. STEP 1
Device uses RF electric field to
manipulate and condense E.coli
bacteria in water
STEP 2
Device uses antibodies and
nanowire sensors to detect E.coli
bacteria
E.Coli trapped
in electric field
Bacteria detection method
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))((2 EKrealrF mDEP  
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13. 13
Solution
This is the device

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αScreen device design

15. 15
αScreen device prototype

16. Proof of concept demonstrated
Prototype under development
αScreen device prototype
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17. • Prof. Mark Reed supports prototyping in Reedlab at Yale University
• Thanks to co-workers
Brian Goldstein, Shari Yosinski, Sonya Sawtelle, Claudia Shin, Phillip
McCown, Shivang Patel, Luye Mu, Christopher Yerino, Hazael Montanaro,
Kane Siu Lung Lo
• αScreen was initially designed as a project in Prof. Koser’s class at Yale
University
• We thank HDTRA for support
Awards and Acknowledgements
• Grand Prize in the NASA Create the Future Design Contest 2011
• CIMIT Primary Care Competition (3rd place US Universities) 2012
• Sobotka Research Award 2011
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18. Thanks to my team!
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Shari Yosinski, Sonya Sawtelle, Claudia Shin, Brian
Goldstein, Christopher Yerino, Hazael Montanaro, Kane
Siu Lung Lo and Prof. Mark Reed