Post on 20-Aug-2020
Lab On a Chip Devices for Water Analysis
1. “Microfluidic supported liquid membrane extraction”. X. Wang and S. Mitra. Anal. Chim. Acta. 2005, 543, 92-98.
2. “A sol-gel approach for fabrication of μ-SPE on PDMS micro channels”. M. Karwa, S. Mitra and D. Hahn. Anal. Chim. Acta. 2005, 546, 22-29.
3. “A microfluidic hollow fiber membrane extractor for arsenic (V) detection.” K. Hylton and Somenath Mitra, Anal. Chim. Acta., 2008, 607, 45-49.
Lab-on-a-chip, Total Analytical System
Sample
Extraction
Sample
Concentration
Separation/
Processing
Detection
On-Chip SLMME
1. “Microfluidic supported liquid membrane extraction”. X. Wang and S. Mitra. Anal. Chim. Acta. 2005, 543, 92-98.
1. “A microfluidic hollow fiber membrane extractor for arsenic (V) detection.” K. Hylton and Somenath Mitra, Anal. Chim. Acta., 2008, 607, 45-49.
Silicon Micro Fabricated Micro-concentrator
for Gas Sensing
1. “Design and fabrication of microheaters for microfluidic channels”. M. Kim, S. Mitra, S. Kishore, and D. Misra, Sensors and Materials 2006, 18, 35-48.
2. “A microfabricated microconcentrator for sensors and gas chromatography”. M. Kim and S. Mitra, J. Chromatogr. A. 2003, 996 (1-2), 1-11.
Top View
456m
31,580m
Contact pad
Contact pad
A conventional Sorbent Trap
A Micro fabricated Microconcentrator
456m
31,580m
54º angle side wall
Crossection View
“Design and fabrication of microheaters for microfluidic channels”. M. Kim, S. Mitra, S. Kishore, and D. Misra, Sensors and Materials 2006, 18, 35-48. “A microfabricated microconcentrator for sensors and gas chromatography”. M. Kim and S. Mitra, J. Chromatogr. A. 2003, 996 (1-2), 1-11.
Sample In
Sample Out to Detector
Pulse Heating
M. Kim and S. Mitra, J. Chromatogr. A. 2003, 996 (1-2), 1-11.
Testing of the Microconcentrator Using Organic Vapors
Computer Flame Ionization Detector
Pulse Heating
Microconcentrator
Sample In
Thermal Stability Test: Pulsed for 3 seconds at Every 5 minutes Interval for 5 hours
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0 100 200 300 400 500 600 700 800 900 1000
Time [sec]
Cu
rren
t [A
]
20700 20800 20900 30000
Microheater Fabrication Steps
• P-type, <100> oriented silicon wafer deposited with 2000 Å oxide
• 1500 Å Silicon Nitride deposited
• Patterning of Silicon nitride and oxide
• Reactive Ion Etching of Silicon nitride and oxide, PR strip
Patterning for Ion Implantation
Deposition of Aluminum alloys
Boron Implantation of Silicon Patterning of aluminum layer
Strip PR Strip PR
KOH Etching
6. Spin-on-glass was coated
7. Polymer was coated
8. Bonding with quartz wafer using
WaferGrip
SEM Image and Cross Section of the Anisotropically Etched Channel of the Microconcentrator
Quartz
Si Silicon Oxide
Heating Layer
Spin-On-Glass (SOG)
Polymer
Silicon Nitride
54º angle side wall
Temperature Characteristic of Heaters with Aluminum Film
v.s. Boron Doped when 36V were applied
0
50
100
150
200
250
300
350
400
450
0 10 20 30 40 50 60 70
Time [sec]
Tem
p [o
C]
Heater with 1 micron thick film
Heater with 3 micron thick film
Heater with boron doped
Temperature Profile of Heater With Al film with Various Voltages Applied
0
50
100
150
200
250
300
350
400
450
0 10 20 30 40 50 60 70 80
Time [sec]
Tem
per
atu
re [
oC
]
36V
30V
15V
cooling profile