Page 1
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Bio-Nano/Micro Fluidic Systems
Prof. Fan-Gang TsengNational Tsing Hua University
Engineering and System Science Dept.
Part A Micro Fluidic Physics
Part B Bio-sample preparation
Part C Operation of Micro Fluidic Systems-Continuous and Digital Fluidic Systems
Page 2
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Part A Micro Fluidic Physics
Page 3
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
outline
1.scaling law of micro/nano fluidics2. Sample collection3. Sample preparation4. Sample transportation/treatment
a. Continuous flow systemb. Digital flow system
5. examples
Page 4
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Scaling law of micro/nano fluidics
• Microfluidics
Navier-Stokes Eq., Reynolds number, Peclet’s number, Capillary number, Knudsen’s number, Froude’s number
• Surface related phenomena
Diffusion, surface tension force
Page 5
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Scaling with length scale
Page 6
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Dimensional and Dimensionless
Page 7
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Microfluidics
Page 8
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 9
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 10
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 11
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 12
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 13
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
uρCpL/k
Page 14
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 15
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 16
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Part B Bio-sample preparation
Page 17
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Sample collection
Page 18
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 19
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 20
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 21
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 22
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 23
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 24
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 25
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 26
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 27
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 28
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 29
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 30
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
120 µm
Page 31
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Sample Preparation
• extraction• purification• separation• amplification• sorting
Page 32
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 33
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 34
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 35
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 36
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 37
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 38
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 39
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 40
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 41
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 42
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 43
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 44
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Capillary Electrophoresis
D. N. Heiger, High Performance Capillary Electrophoresis - An Introduction, Hewlett-Packard Co.
Electrokinetic phenomena: electrophoresis and electro-osmosisP flow EOF
0 ms
60 ms
150 ms
Page 45
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
P DEP N DEP
Page 46
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 47
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 48
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 49
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
(magnetic beads)
Page 50
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 51
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 52
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Part C Operation of Micro Fluidic Systems
Page 53
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
• Digital Fluidic Systems1. droplet generation2. droplet suspension3. droplet surface manipulation
Micro Fluidic Systems:
EWOD, CJ Kim, UCLAµTransducers sourcebook, 98
• Continuous Fluidic Systems1. micro channel2. mixing/reaction,3. flow logic, 4. flow detection5. fluid actuation (pump, valve)6. integration and package
Page 54
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
• Reagent: storage, reconstitution, sample volume• fluidic device: fabrication,micro flow
measurement, and characterization• Surface modification•Integration• Package: interconnects, filling/bubbles/ dead
volume, leakage• control algorithms, data processing,
and communicaiton• Power consumption/ effeciency• Passive or active• reusable or disposable
Challenges for Continuous Micro/nano fluidic system
Page 55
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
One example of Continuous Micro/nano fluidic system
Abe Lee, 2003
Page 56
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 57
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Flow channels1. Mixers 2. Extractors3. Flow logics
Page 58
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Flow channelsBulk micromachining Surface micromachining
Buried micro channels Polymer micro channelsµTransducers sourcebook, 98 µTransducers sourcebook, 98
µTransducers sourcebook, 98
Anti-reflection coating
SU-8
SubstrateStandard UV exposure
Partial UV exposure
(a)
(b)
(c)
Anti-reflection coating
Stacked channel
Channel release
(d)
(e)
(f)Chuang, Tseng, MEMS’02
Page 59
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
MixersSharp turn Flow lamination
Plume mixers Active mixers
µTransducers sourcebook, 98
µTransducers sourcebook, 98
µTransducers sourcebook, 98
CHAOTIC MICRO-MIXER
H. Suzuki, C.-M. Ho, MEMS 02
Page 60
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Separation
µTransducers sourcebook, 98
Electrophoresis Extractors
Page 61
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Flow logics
Flow rectifier
Coanda effect Flow oscillator
µTransducers sourcebook, 98
Page 62
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Fluidic sensors
1. Flow sensors2. Viscosity/density
Page 63
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Flow sensorsThermal flow sensors
Cantilever drag flow sensor Lift force flow sensorCaltech, UCLA
µTransducers sourcebook, 98
C. Lin, F. G. Tseng, Sensors J. 2002
Fiber Floating Element
Page 64
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Viscosity/density sensors
Acoustic Wave Sensors, 97
Page 65
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Thermal/Fluidic actuators
1. Valves
2. Pumps
Page 66
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 67
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 68
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Micro valve
Page 69
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
ValvesCheck valves Active valves
(thermal pneumatic)
µTransducers sourcebook, 98
Page 70
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 71
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 72
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 73
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 74
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 75
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 76
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 77
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Page 78
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Actuation Mechanisms for Microvalves
• Pneumatic-Large linear forces-Requires external force generation ad external interconnections
• Thermal Expansion-Larger linear forces-Relatively slow, may heat fluid, consume large amounts of power
• Peizolelectric-Very Large forces-Very small movements, large voltages
C. Rich and K. Wise, Proc. MEMS’99, 130-134
C. Grosiean et al, Proc. MEMS’99, 147-152
S. Shoji et al, Transducers 91, 1052-1055
Page 79
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
M.Huff etal, Transducers’93, 88-101
K. Yanagisawa et al, Transcucers’93, 102-105
• Electrostatic
-High but nonlinear forces, large movements
-requires high voltages
• Electromagnetic
-Large forces and movement, very fast, low power
-Complex fabrication process/difficult to integrate
• Shape Memory Alloy (SMA)
-Very large force
-Slow response, need heat upCarien & Mastrangelo, MEMS-00
Page 80
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Carien & Mastrangelo, MEMS-00
Page 81
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Micro pump (with or w/o moving part)
Page 82
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
(Ion drag)
(concentration difference)(suction force by high velocity/low pressure)
Page 83
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Pressure driven pumpMembrane Pump
Rotary Pump
G. Kovacs, Micromachined Transducers Sourcebook, 1998
Diffuser Pump
G. Kovacs, Micromachined Transducers Sourcebook, 1998
G. Kovacs, Micromachined Transducers Sourcebook, 1998
Ultrasonic Pump
Page 84
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Electro driven pump (ion drag)Electroosmotic Pump EHD Pump
MHD PumpCapillary Electrophoresis by Electroosmosis pumping
H. Chujo et al., MEMS’03
Lorentz Force pumps fluidF=I×B
Page 85
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Filters
Page 86
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Filters
µTransducers sourcebook, 98
Horizontal
Vertical
H. Sato et.al., MEMS’03
Page 87
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Flow systems
1. Interconnects
2. Packaging and integration
Page 88
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Interconnects
Single point Multi point
µTransducers sourcebook, 98
Page 89
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Packaging and integration
Snap-together plastic package,injection mold, gluing sealing
Stacking method
µTransducers sourcebook, 98
Page 90
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
類比微流體系統:
1.Biomedical Sensing System
3. Drug delivery
4. Gas/liquid chromatography
5. Micro Power Generator
Page 91
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Micro Total Analysis System (µTAS)or Lab on the chip (LOC)
i-STAT’s handheld clinical analyzer and disposable cartridge
Biologixs pH sensor cube and reader
Porton Diagnostic’s potassium sensor and reader
µTransducers sourcebook, 98
Page 92
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Drug deliveryMicro needle array
needle+blood sensingASME IMECE’00MEMS’98 P. Griss and G. Stemme, µTAS’02
K. Oka et al., Transducers’01
Page 93
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
微系統科技的應用研究舉例(Bio-MEMS)
Insulin pump (Debiotech, Switzerland)
µTransducers sourcebook, 98
Page 94
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Gas/liquid chromatography
µTransducers sourcebook, 98
Page 95
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Micro Power GeneratorMicro Fuel cellMicro battery
Bial Fuel cellDirect Methonal Fuel cell
Y. Seo and Y.-H. Cho, MEMS,03 M. Chiao, K. B. Lam, and L. Lin, MEMS,03K. B. Lee, F. Sammoura, and L. Lin, MEMS,03
Page 96
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Digital Micro Fluidic Systems
1. droplet generation
2. droplet suspension
3. droplet surface manipulation
Page 97
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Droplet generatorsHP
Sharp, Inc, MEMS 96
Epson
E.S. Kim, USC, MEMS98
Page 98
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
液珠懸浮控制
(S. Nilsson, et. al., µTas’00)
Page 99
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
微液珠平面驅動方式
•微液珠驅動方式:1. 靜電及電潤濕 [2-4] 2. 光驅動法 [5] 4. 固態液體珠 [6]5. 非對稱結構 [8]6. 熱毛細力 [9]7. 結合Marangoni效應, 熱毛細力, 凝結及成核 效應[7]
Most of them are employing surface tension gradient!!!
Lee. J, Sensors and Actuators 2002
K. Ichimura, Science, 2002
P. Ausslllous, Nature, 2001
O. Sandre, Physical Review E, 1999
J. C. Chen, Science, 2001
Page 100
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Electrostatic
(Masao Washizu, IEEE 1998 ) (Altti Torkkeli, IEEE 2001 )
• Very high voltage, • electrolysis problem, • charged bio-molecules may be attracted by electrical field
Page 101
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Electrowetting
(Sung Kwon Cho, IEEE 2002 )
EWOD (ElectroEetting on Dielectric)
CJ Kim, UCLA
Page 102
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Moving
Creating
Separation
(Pei Yu Chiou, IEEE 2003)
OWE (Opto-Electrowetting)Electrowetting
Page 103
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Photonic & SAMs
(K. Ichimura, Science 2000)
Page 104
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
0306090120150180210
0 1 2 3 4 5Distance(mm)
Temperature(℃
) 30V-Xdirection
1mm
0 s
0.5 s
1 s
1.5 s
2 s
4 s
0 s
0.5 s
1 s
1.5 s
2 s
4 s
1 µl 0.1 µl
2 mm 2 mm
•Droplets Moving Behavior
2.17mm
1 µl0.1 µl
Marangoni Effect
Marangoni flow
Capillary flow
TH TL
Temperature distribution
F. G. Tseng et al, Transducer’03
Page 105
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
(Susan Daniel, Science 2001)
Marangoni flow
Capillary flow
TH TL
Marangoni +capillary+ coalesces Effect
Droplet movement ~10 cm/s, 10 times faster
Hydrophilic Hydrophobic
Page 106
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Surface Roughness
Wettability Switching by Surface Roghness Effect (Bo He, IEEE 2003 )
Winzelγsv
γlv
θ’γsl
Cassie
a b
Water
θγ
γγθ cos
)('cos rr
lv
slsv =−
=
1cos'cos −+= ff θθ
Page 107
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Superhydrophobic & Gravity
Hydropphobic powder (20µm) coating (Pascale Aussillous, Nature 2001)
Water Droplet Weight 7mg with tilt angle of surface 1°˚ (Masashi Miwa, Langmuir 2000)
Liquid Marble (Powder coating)Superhydrophobic Surface (SAMs)
Page 108
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
(a). Au on glass side+ SAMs
θ=110.7°˚Hydrophobic SAMs*
θ=56.7°˚Hydrophilic SAMs (-COOH)
(b) Au on micro posts
θ=109.9°˚dia: 60μm pitch:40μm
θ=73.8°˚dia:80μmPitch: 180μm
(c) Au on micro posts+SAMs
θ=143.6°˚Hydrophobic SAMs*dia: 60μm pitch:40μm
θ=12.4°˚Hydrophilic SAMs(-COOH)dia:80μmPitch: 180μm
Fan-Gang Tseng, and Shu Chun Chien, “Droplet Movement Induced by Nano Assembled Molecules And Micro Textures “ Nanotech2004
+
SAMs*: CH3(CH2)17SH
Combination of surface roughness and SAM
Page 109
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Comparasion
Principle Max. Velocity(mm/s)
Droplet Size(µl) Power
Electrstatic(Altti Torkkeli, IEEE 2001) 10 2 ~ 50 Yes(124VAC)
Electrowetting(S. K. Cho, IEEE 2002) 250 1 Yes(100VAC)
Optic(K. Ichimura, Science 2000) 0.035 2 Yes
Temperature Gradient(Susan Daneil, Science 2001) ~ 20 0.001 ~ 1 Yes
Roughness(Bo He, IEEE 2003) ? 7 No
Gravity(P. Aussillous, Nature 2001) ? 1 ~ 10 No
Page 110
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Digital fluidic systems:
1. Biomolecule Micro Array
2. Micro Droplet Systems
Page 111
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Micro ArraysDNA Micro arrays
Chemically synthesize
Mechanically spot
DNA array system:Standford University, Brown group
Capillary
Tip
Bio-reagent
Glass slideUltrasound wash bath
Petri dishPrintingTip array
Translation stage
(Affymetrix,USA,from transducers source book)
• High throughput• Low volume• High speed screening
Page 112
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Microdroplet Drug Releasing
Open connection channle
Droplet Volume
B. de Heij et al, MEMS’02
Page 113
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Digital µTAS or LOC
Page 114
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Continuous vs. Digital Fluidic system
Continuous digital
1. Components versitle single2. Device complexity complex simple3. fabrication difficult depends4. integratability difficult easier5. Flow sesing/control complex depends6. Flow resistance high low7. Dead volume high low8. reuse difficult possible9. System cost high depends10.Fluid flow enclosure (half)open11.evaporation low high
Page 115
NTHU ESS
Prof. Fan-Gang Tsengµ-Nano Bio & fluidics System Lab
Reference
1. G. T. A. Kovacs, “Micromachined Transducers Sourcebook”, McGraw-Hill, 1998
2. Abe Lee, lecture notes UCI-BME 295, 20033. Proceedings of Micro Total Analysis Systems,
98, 00-044. Proceedings of IEEE MEMS conference, 96,98,
02, 035. Proceedings of IEEE Transducers’01, 036. Proceedings of ASME IMECE MEMS, 98, 99,
00.