lihui wang, hiromasa oku, masatoshi ishikawa. university of tokyo, japan
DESCRIPTION
Development of variable-focus lens with liquid-membrane-liquid structure and 30 mm optical aperture. (e). (a). (f). (b). Lihui Wang, Hiromasa Oku, Masatoshi Ishikawa. University of Tokyo, Japan [email protected]. (g). (c). (h). (d). Research Background. Normal Lenses : - PowerPoint PPT PresentationTRANSCRIPT
Ishikawa Oku LaboratoryUNIVERSITY OF TOKYOhttp://www.k2.t.u-tokyo.ac.jp/
Development of variable-focus lens with liquid-membrane-liquid structure and 30 mm optical aperture
Lihui Wang, Hiromasa Oku, Masatoshi Ishikawa.University of Tokyo, [email protected]
(a)
(b)
(c)
(d)
(e)
(f)
(g)
(h)
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Research Background
• Normal Lenses:
• Single lens with Variable-focus:
wikipeida.org
glasses plastic
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Related Research
• Liquid-Membrane Lens• single liquid chamber• deformable wall (1or2)• [−6.0 +7.6] diopters• optical aperture 7mm• 1ms response time
• Liquid-Liquid Lens• [-50 +50] diopters• optical aperture 3.0mm• wavefront error 80.3nm
at 109mm focal length• 2ms response time
H Oku, et al. Applied Physics Letters, 2009
H Oku, et al. Optics Express, 2004
Dynamorph Lens Driving mechanisms:pressure, electreowetting, dielectric
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Dynamorph Lens
Un-solved Problem (Lens Aperture)
• Liquid-Liquid Structure (review Dynamorph Lens)• Capillary Length:
• If D(lens aperture) < < lc(capillary length), Gravity Effect is negligible.
Interface tension: 34.8mN/mDensity water: 0.997g/cm3 capillary length=12.7mm >> 3mm (lens aperture)Density PDMS :0.975g/cm3
• What if Large Optical Aperture!• Key Point: Capillary Length Surface Tension???
okay
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Research Purpose
• Variable-Focus Liquid Lens with Large Optical Aperture • Structures of liquid lens (30mm)• Sufficient optical performance
• Theoretical analysis • Membrane Deformation• Spherical Deformation• Symmetry Deformation
• Experiment • A prototype of liquid lens with 30m aperture• Evaluate optical performance
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FollowingNext slide
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Lens Structure
• Liquid-Membrane-Liquid Structure• elastic force surface tension capillary length
Liquid-Liquid Lens• optical performance
Liquid-Membrane Lens• large aperture
Liquid
Membrane
Liquid
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Membrane Deformation 1/2
• 30mm diameter with boundary clamped elastic membrane• Silicon membrane parameters:
• 30mm aperture, 0.1mm thickness, 1.8MPa Young modulus, 0.45 Passion ratio• Assuming uniform pressure acting on one side
• uniform pressure of [1 10 20 40 60 80 100 130] Pa
-15 -10 -5 0 5 10 150
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
radial coordinate (mm)
mem
bran
e de
form
atio
n (m
m)
p=1
p=10
p=20
p=40
p=60
p=80
p=100
p=130
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Membrane Deformation 2/2
• Recall capillary length
• assuming Water and PDMS infused (referring Dynamorph Lens )
Elastic force average
liquid-membrane-liquid is a possible solution
Liquid-Membrane-Liquid vs Liquid-Membrane
Elastic force
0 20 40 60 80 100 120 1400
0.5
1
1.5
2
2.5
3
3.5
4
external pressure(Pa)
mer
idio
nal s
tres
s of
ela
stic
tity(
N/m
)
Capillary length
0 20 40 60 80 100 120 1400
20
40
60
80
100
120
140
external pressure (Pa)
capi
llary
leng
th (
mm
)
meridional of elastic forceliquid-membrane-liquid lens
0 20 40 60 80 100 120 1400
0.5
1
1.5
2
2.5
3
3.5
4
mer
idio
nal o
f ela
stic
forc
e (N
/m)liquid-membrane-liquid lens
liquid-membrane lens
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Spherical Deformation 1/2
• Comparison of 3mm variable liquid lenses
Liquid-Liquid Lens vs Liquid-Membrane-Liquid Lens• Evaluate Criteria: wavefront error Peak-to-Valley (PV)
Root-Mean-Square-Error (RMSE)
Liquid-Liquid Lens• Aperture 3mm• Liquid-Liquid interface• Wavefront error (PV, RMSE)
New Model• Aperture 3mm• Liquid-Membrane-Liquid• Wavefront error (PV, RMSE)
Data from exist paperExperiment data
Data from simulation1. Modeling 3mm silicon membrane2. Acting pre-gravity map of water-PDMS3. External pressure loaded4. 3D deformation optical path lengths5. Optical path lengths spherical surface
H Oku, et al. Applied Physics Letters, 2009
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Spherical Deformation 2/2
• Comparison of 3mm variable liquid lens
Liquid-Liquid Lens vs Liquid-Membrane-Liquid Lens
Peak-to-Valley (PV)
Root-Mean-Square-Error (RMSE)
shows smaller wavefront error
40 60 80 100 120 140 160 180 200 220 240100
200
300
400
500
600
focal length (mm)
PV
val
ue (
nm)
liquid membrane pvliquid membrane liquid pv
40 60 80 100 120 140 160 180 200 220 24020
40
60
80
100
120
140
160
focal length (mm)
RM
SE
val
ue (
nm)
liquid membrane rmseliquid membrane liquid rmse
liquid-liquid lensliquid-membrane-liquid lens
liquid-liquid lensliquid-membrane-liquid lens
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Symmetry Deformation 1/2
• External pressure elastic force capillary length• elastic force relays on external pressure loaded.• gradually increasing
• Conform by Finite Element Simulation (ANSYS)• membrane parameters:
– 30mm aperture, 0.1mm thickness, boundary clamped– 1.8MPa Young modulus, 0.45 Passion ratio
• infused liquid pair– Water and PDMS liquid
• meshing the membrane into 1425 elements• large deformation under [0 ~ 120]Pa
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Symmetry Deformation 2/2
• External Pressure : 0Pa 5Pa 8Pa 10Pa 20Pa … …1
MN
MX
X
Y
Z
0
.476E-04.953E-04
.143E-03.191E-03
.238E-03.286E-03
.334E-03.381E-03
.429E-03
JAN 15 201314:28:37
NODAL SOLUTION
STEP=1SUB =300TIME=60UZ (AVG)RSYS=0DMX =.429E-03SMX =.429E-03
1
MN
MXX
Y
Z
0
.667E-04.133E-03
.200E-03.267E-03
.333E-03.400E-03
.467E-03.534E-03
.600E-03
JAN 15 201315:54:35
NODAL SOLUTION
STEP=1SUB =300TIME=60UZ (AVG)RSYS=0DMX =.600E-03SMX =.600E-03
1
MN
MXX
Y
Z
0
.711E-04.142E-03
.213E-03.284E-03
.355E-03.427E-03
.498E-03.569E-03
.640E-03
JAN 15 201316:07:17
NODAL SOLUTION
STEP=1SUB =300TIME=60UZ (AVG)RSYS=0DMX =.640E-03SMX =.640E-03
1
MN
MX X
Y
Z
0
.751E-04.150E-03
.225E-03.300E-03
.375E-03.450E-03
.525E-03.600E-03
.675E-03
JAN 15 201316:38:56
NODAL SOLUTION
STEP=1SUB =300TIME=60UZ (AVG)RSYS=0DMX =.675E-03SMX =.675E-03
1
MNMX X
Y
Z
0
.905E-04.181E-03
.272E-03.362E-03
.453E-03.543E-03
.634E-03.724E-03
.815E-03
JAN 15 201317:30:17
NODAL SOLUTION
STEP=1SUB =300TIME=60UZ (AVG)RSYS=0DMX =.815E-03SMX =.815E-03
0 20 40 60 80 100 1200.005
0.01
0.015
0.02
0.025
0.03
0.035
0.04
0.045
external pressure (Pa)
dist
ance
(m
m)
Symmetry Deformation• external pressure >>26Pa• point of maximum deformation moves to center step by step
Water: 0.997g/cm3
PDMS: 0.975g/cm3
----------------------------------
0.022g/cm3
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Experiment 1/2
• Prototype• Liquid-Membrane-Liquid Lens
• with 30mm aperture
Liquid Density Refractive
Glycerin 1.25 1.4732
SantoLight5267 1.26 1.6737
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Experiment 2/2
• Optical performance• USAF1951 Chart• Resolution at f=150 mm• System magnified 2X
System magnified 2X
Vertical bar(Group4, Element2)
Horizontal bar(Group4, Element1)
Horizontal Vertical 8.975 lp/mm 8.000 lp/mm
Comparing with 11.6 lp/mm spherical interface(ZEMAX)
Light USAF1951 Liquid Lens Imager
1.5f window
liquid 1 liquid 2
window membrane 3f
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Conclusion and Future Work
• Variable-Focal Liquid Lens with Large Optical Aperture • Liquid-Membrane-Liquid Lens with 30mm aperture • Calculation & Simulation Feasibility• Experiments Prototype & Resolution
• Future Work• Available liquid pairs.• Application ???
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Acknowledgement
• Co-authors & Supervisors:• Dr. Hiromasa Oku, • Prof. Masatoshi Ishikawa.
Ishikawa Oku Laboratory http://www.k2.t.u-tokyo.ac.jp/
Sincerely appreciate for your time.