A Highly Compact Lensless HighA Highly Compact Lensless High
Transcript of A Highly Compact Lensless HighA Highly Compact Lensless High
A Highly Compact Lensless High-ResolutionA Highly Compact Lensless High Resolution Optofluidic Microscope (OFM)
Xiquan CuiXiquan [email protected]
California Institute of Technology
10μm
Caltech Biophotonics LaboratoryCaltech Biophotonics Laboratory10μm 1
Presented at the evening meeting of theSanta Clara Valley Chapter, CPMT Society, IEEEJanuary 14, 2009 www.cpmt.org/scv/
Redesigning the microscopeRedesigning the microscope
We abandon the conventional microscopy design and uses a novel aperture array for high resolution cell-level imaging.
Images of C. elegans
50 μm
- compact (~ the size of a dime)- potentially cheap ($10’s)potentially cheap ($10 s)
X. Cui et. al, PNAS, 105, 10670 (2008)
Caltech Biophotonics LaboratoryCaltech Biophotonics Laboratory
OverviewOverview
• Motivation• Intensity contrast OFM• Intensity contrast OFM
(a) Gravity driven OFM (GD OFM)- Automated and quantitative OFM microscopy- Phenotype characterization of C. elegans- Resolution issueResolution issue
(b) Electrokinetic OFM (EK OFM)- Spherical/ellipsoidal cells imagingp p g g
• Conclusions and future directions
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Motivation
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Conventional optical microscopyConventional optical microscopy
Advantages:• Noninvasive• Noninvasive• High resolution• Comprehensive microscopy informationComprehensive microscopy information• Gold diagnosis standard
Disadvantages:B lk• Bulky
• Expensive
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Optofluidic microscopyOptofluidic microscopy(OFM)(OFM) y
Microfluidic channel
(OFM)(OFM)CCD or CMOS chip
Opaque layer
xTop view
Hole (A)
ange
s
Slanted nanohole 1D arrayHole (B)
Hole (D)Hole (C)Hole (B)Hole (A)20 µm
mis
sion
chaImprove resolution in both x and y direction
Hole (C)
Tran
sm
Hole (D)
Linear shifting factorFinal !!!
( )
timeNucleated blood cell image is from http://www.wadsworth.org/chemheme/heme/glass/slide_011_nrbc.htm
X. Heng, Lab on a Chip, 6, 1274 (2006)6
Advantages of OFMAdvantages of OFM
• On-chip high resolution imaging• On-chip high resolution imaging- Compact- Low cost
• MicrofluidicsSh j ti- Sharp projection
- Bio-friendly- High efficiency and throughput - Automatic operation
C. elegans images
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Intensity contrast OFM
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Complete onComplete on--chip OFMchip OFM• Small as a dimeSmall as a dime
• High resolution (~1μm)
• Imaging & pump are all - on chip
electrodes
IlluminationSpecimen
IlluminationSpecimen
GoldPMMA
aperture
PDMS
A t
PDMS channel
A t
PDMS channel
G it d i OFM El t ki ti OFM
CMOS Sensor PixelCMOS Chip Packaging
Al layer
CMOS
Flow
Apertures
Al layer
CMOS
Flow
Apertures
Gravity driven OFM
(GD OFM)
Electrokinetic OFM
(EK OFM)
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X. Cui et. al, PNAS, 105, 10670 (2008)
Gravity driven OFM (GD OFM)Gravity driven OFM (GD OFM)
IlluminationSpecimen
IlluminationSpecimen
PDMS PDMS Microfluidic channelchannelchannel
Al layer
CMOS
Flow
Apertures
Al layer
CMOS
Flow
Apertures OFM apertures
Al layer FlowAl layer Flow
• Complete on-chip device
C. elegans flowing in OFM(top view)
Complete on chip device • Self-sustained flow• Bio-compatible
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Automated and quantitative OFM microscopyAutomated and quantitative OFM microscopy
XY vChannel
XY vChannel
SpecimenSpecimen
δY=500nm
L= 9.9μm 1μm
∆X θδY=500nm
L= 9.9μm 1μm
∆X θδY=500nm
L= 9.9μm 1μm
∆X θδY=500nm
L= 9.9μm 1μm
∆X θOFM imagingOFM imagingOFM imaging
δY 500nmδY 500nmδY 500nmδY 500nm
Cross correlation
<50%Cross correlation
<50%<50%
• Automated operation
• Digitized image >50%
Screen out>50%
Screen out
Screen out
Screen out
g g
• Quantitative evaluationAutomatic
measurementAutomatic
measurement
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Resolution comparisonResolution comparisonOFM imaging parameters:• Illumination:
~ 20 mW/cm2 white light,OFM the intensity of sunlight
• CMOS sensor line rate: • 1k fps
Direct sensor
imaging
1k fps• Specimen velocity (V):
~500 μm/s• Sampling grid:(10μm pixel)
20X
• Sampling grid: δX = δY =0.5 μm
• Aperture size (D): NA=0.420X
microscope 1 μm• Microfluidic channel:
width 50 μm, height 15 μmC. elegans
OFM has comparable resolution as a ti l i
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conventional microscope.12
Phenotype characterization of Phenotype characterization of C. C. eleganselegans
Wild t
Performed automated
phenotype characterization
aWild-type
50μm50μm
a) Automated
Dpy 7
b Sma-350μm50μm b) Image 1 worm / 2.5 sec
c) Computerized worm length and area measurement
300d 13e
cDpy-7
50μm50μm
and area measurement
d) Drop and go
100
150
200
250
engt
h (μ
m)
9
10
11
12
Wid
th (μ
m)
0
50
100
Le
7
8
9W
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Resolution Issues Resolution Issues 4
3
4
M ( μ
m)
0.5
1
issi
on (a
.u.)r
Point source
2
on o
f OFM
-5 0 50Tran
smi
r (μm)
HX
Z
Y
1
Res
olut
io
AlSU8
CMOS pixel
10-2 10-1 100 1010
H (μm)
CMOS pixel
Prototype resolution = 0.9 microns (Sparrow’s Criterion)
50μm
15 micron tall channel 25 micron tall channel
Shallow channels give better images.Shallow channels give better images.
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ElectrokineticElectrokinetic OFMOFM ((EKEK OFMOFM))(Collaborated with Lap Man Lee)( p )
electrodesPDMS
illumination
GoldPMMA
aperture
CMOS Sensor PixelCMOS Chip Packaging
• Spherical/ellipsoidal cells imagingSpherical/ellipsoidal cells imaging• Easy to be integrated on a chip
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ElectrokineticElectrokinetic Drive: Why? Drive: Why?
1. EK enables uniform cell transportation.cell transportation.
2. Electroorientationaligns cells.
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OnOn--chip EK OFMchip EK OFM
10μm
OFM
b d f h jb d f h j
conventional microscope
kb d f h
microscope
electrodes
Chlamydomonas mulberry pollen spores
polystyrene microsphere
electrodes
GoldPMMA
PDMS Uniform motions of samples yield perfect EK OFM i
CMOS Sensor PixelCMOS Chip Packaging
aperture OFM images.
CMOS Sensor PixelCMOS Chip Packaging
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Conclusions and future directions
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Conclusions Conclusions
• Created world’s smallest high resolution microscope on a single chipmicroscope on a single chip
• Automated & parallelizable on-chip cell microscopy methodmicroscopy method
• The low cost and compactness of OFM can change the way we use microscopescan change the way we use microscopes
C elegans10μm
10 C. elegansChlamy
10 μm
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AcknowledgmentAcknowledgment
Biophotonics group: Collaborators:Prof. Demetri Psaltis
Prof. Changhuei Yang
Lap Man Lee
Prof. Paul W. SternbergDr. Weiwei ZhongProf. Axel Scherer
F di S
Xin HengMatthew LewDr. Jigang WuD Z hid Y b
Prof. David Erickson (Cornell)Dr. L. Ryan Baugh
Funding Sources:DARPA Center for Optofluidic Integration, NIH
Dr. Zahid YaqoobEmily McDowellHan ShuoG oan Zhang NIH,
Coulter Foundation,Guoan ZhangJian RenDr. Vahan SenekerimyanArthur ChangArthur ChangJose PachecoEdward Hsiao
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Thank you!Thank you!
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