National Personal Protective
Technology Laboratory
End-of-Service Life Program
North 5N6: 5/14 - 5/15
1.748
250
1.744
1.742
150
1.74
100
1.738
1.736
50
1.734
0
1.732
0
200
400
600
Minutes
Contact Info
zpx5@cdc.gov
412-386-6775
Coupled pSi
800
1000
1200
S3 Volts
Jay Snyder
ppm Toluene ( outlet )
1.746
200
Presentation Outline
 Present Work (electronic system)
 Cartridge-Sensor Integration/Testing/Evaluation
 Future Work (electronic system)
 System Redesign
 Optical System
 An Alternative to the Chemiresistor
MSA: 5O27 (TF): 4/22 - 4/23
mid bed brkthr
600
1.785
1.78
full bed brkthr
400
1.775
300
1.77
200
1.765
100
1.76
0
-100
0
500
1000
Minutes
1500
1.755
S3 Volts
ppm Toluene ( outlet )
500
End-of-Service Life Detection System
RF Power
Transmission
Data
Reception
Face mask unit
Filter/mask
electrical
interface
Embedded
Coils
ChemAlertTM Filter
(cross-section)
Embedded
wireless
sensors
ESL
indicators
Collaboration with Respirator
Manufacturers
 Dräger
 MSA
 North Safety Products
 Scott Health & Safety
 Sundström Safety AB
 Survivair
Examples of Sensor Integrated Cartridges
MEMS Sensor Generations
Sensor Assembly
Si chip
1
2
8
3
7
4
6
5
Cover glass
Equivalent
circuit
Vmod+
2
3
1
V1 V2 V3
5
4
6
Vmod -
Sensor
TO-5
Small is Beautiful: From Bulk to Nano Scale
Nanochemistry
Solid state
science
1 m
Bulk
(crystalline nanoparticles, 1-100 nm)
1 nm
o
A
The bottom of nanoscale
S
(> 1m)
10 nm
100 nm
Molecular chemistry
S
S
S
S
S
Gold nugget
nanosphere
5 nm
nanorods
nanoprisms
Aun clusters
Used with permission from Carnegie Mellon University
Performance of a CGNP
1000 ppm
Toluene
C8H17SH
(C8)
GC
1200
1000
GC
Response
T response ?
800
600
400
200
0
50
100
Minutes
150
0
200
ppm
1.02
1
0.98
0.96
0.94
0.92
0.9
0.88
0.86
GC_ppm
Sensor 1Vo
Toluene 1000: 3W7: Carbon 50: Air 32: RH 23
Properties
 Easy to handle
 Air stable.
 Soluble in organic solvents*.
 Can be coated on substrates by ink-jetting, dipping, spinning
and spraying.
 Can be modified
 Size and shape.
 Functional end groups of organic monolayer.
• *Solubility determined by the nature of the monolayer.
• Reusable
Solvents and Test Setup
 Toluene (500 & 200 ppm)
 DuPont Enamel Reducer (500 ppm)
 19+ groups of compounds
 Trichloroethylene (500 ppm)
 25 & 80 % RH
Thick/Thin Film Toluene Response
Thick Film vs Thin Film Toluene Responses
Thick Film
120
Thin Film
100
Series1
60
40
20
Sv
5F
7
D5
K7
(C
M
TO
5
N5
N6
5I
6
M
(T
F)
Sv
5K
9
(T
F)
M
5K
1
(T
M
F)
5O
27
M
(T
5I
F)
15
C
M
(T
F)
D5
O
19
(T
Su
F)
5M
16
(T
Su
F)
5J
22
(T
F)
D5
N7
(T
F)
Sv
5O
2(
TF
N5
)
J3
7
(C
M
)
N5
O
4
Summary of Response to 500 ppm Toluene
)
0
Sv
5J
6
uV/ppm
80
TC
E
E
uP
TC
D
50
50
0/
80
R
H
H
H
0/
25
R
/2
5R
20
0/
25
50
0/
80
/5
00
/2
5
50
0
To
l
To
l
To
l
uv/ppm
Test Results
Test Summary (One Brand)
120
100
80
60
40
20
0
Preliminary Conclusions from
Cartridge Testing
 Uniform film thickness devices were more sensitive than earlier device.
 Detection of contaminants at high RH levels was not acceptable.
 Sensor location (side vs center) made little difference.
 Inconsistent sensor performance.
 No failures due handling and transportation?
 Did not observe aging effects.
Tasks for 2009
 Materials task
 develop new nanoparticle materials (gold nanocrystals and nanoclusters) for
chemiresistive response to analytes of interest
 support generation of nanoparticle materials for chemiresistive device and
system development
 test materials for chemiresistive response
 Manufacturing task
 jetting development of nanoparticle inks
 inkjetting support for chemical sensor device and system development
 Sensor task
 integrated gravimetric sensor characterization to analytes
 integrated capacitive humidity sensor characterization and refinement
 chemiresistor device design support
Tasks for 2009
 System Integration task
 preconcentrator design and implementation
 chip bonding of preconcentrator onto passive chip system
incorporating chemiresistors
 testing with analytes of passive chip system
 incorporation of chemiresistors, humidity sensor and
gravimetric sensor onto integrated chip platform with active
circuitry
 Wireless task
 system power estimation
 design and on-chip implementation of wireless power
conditioning circuitry
 near-field antenna design for power transfer
 design of output communication circuits
Wireless Power and Communication
Phased Implementation
Wireless
Chemsensor
power/comm
microsystem
chip
Single-chip
chemsensor and
power/comm
~½”
flex board
System-in-package
chemsensor,
power/comm and coil
~0.2”
coil
~1”
1-2 years
2-3 years
3-4 years
Gen Six Configuration
Next Generation MEMS Device
Data
Collection
Humidity
Sensor
&
Interpretation
Gravimetric
Sensor
Sample in
Pre-concentrator
Chemiresistor
Sensor
Nanosensors from Porous Si
• Low Power
• Mass produced, low cost
• Tunable Optics
• Sensitivity: high surface area
• Surface easily modified
• Impervious to electrical
interference
Plan View
Wide range of pore sizes possible
10nm
20 m
100nm
1 μm
General Sensing Scheme
Reflectivity
1 .0
0 .8
Spectral Band Shifts
0 .6
0 .4
0 .2
0 .0
5 00
60 0
7 00
8 00
90 0
Wavelength
Air
Organic Vapor
Toluene
Vapors:
ppm to ppb
sensitvity
Attachment to Optical Fiber
CCD Spectrometer
No
Vapor
400
Vapor
1000
Wavelength (nm)
No Vapor
Peak Position
Light Source
Relative Intensity
Optical Fiber Sensing Scheme
No
Vapor
0
Vapor
Time (sec)
Vapor
100
Photodiode
Detector
No
Vapor
400
Vapor
1000
Wavelength (nm)
No Vapor
Peak Position
Narrowband
LED Source
Relative Intensity
Optical Fiber Sensing Scheme
No
Vapor
0
Vapor
Time (sec)
Vapor
100
Carnegie Mellon Team, Past and Present
 MEMS and system: Gary Fedder
 Sarah Bedair, Kristen Dorsey, Nathan Lazarus, Suresh Santhanam,
John Wu
 Nanoparticles: Rongchao Jin
 Niti Garg
 Polymer characterization: Tomek Kowalewski
 Rui Zhang
 Sensors: David Lambeth
 Greg Barchard, Bo Li
 Polythiophenes: Richard McCullough
 Jessica Cooper, Mihaela Iovu, Genevieve Sauvé
 Wireless: Jeyanandh Paramesh
 Jetting: Lee Weiss, Larry Schultz
Collaborators
 Tony Rozzi, EG&G
 Michael Sailor, UCSD
 Anne Ruminski, UCSD
 Brian King, UCSD
 Jay Snyder, NIOSH
Contributory Programs
 CDC/NIOSH
 USAF Multidisciplinary University Research
Initiative
 Sensors for a Safer America
 University of California Research Funds
Quality Partnerships Enhance Worker
Safety & Health
Visit Us at: http://www.cdc.gov/niosh/npptl/default.html
Disclaimer:
The findings and conclusions in this presentation have not been
formally disseminated by the National Institute for Occupational
Safety and Health and should not be construed to represent any
agency determination or policy.
Thank you