The Nanoconverter :
a novel flexure-based mechanism
to convert microns into nanometers
Dr S. Henein
CSEM [Since 2006] : Senior R&D Engineer, Swiss Center for Electronics and Microtechnology
BFH [Since 2005]: Lecturer, Bern University of Applied Sciences
PSI [2004-2006] : Group Head, Division of Mechanical Engineering Sciences, Paul Scherrer Institut
Dr M. Stampanoni, U. Frommherz, M. Riina
Paul Scherrer Institut
7th International Conference of the European Society for Precision Engineering & Nanotechnology
Bremen, Germany, 23rd May 2007
Outline
• Introduction: context and goal of this development
• Examples from the state of the art
• Working principle of the Nanoconverter
• First implemented version
• First application (Phase Constrast Interferometry)
• Conclusion & Prospects
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Goal
• Produce a linear motion with better than 10 nanometer accuracy over 15
microns motion range
• Avoid using piezo-actuators and associated driving electronics
• Use any commercial « Pusher » units (stepper motor & lead screw) having an
accuracy of 1 micron
• Reduction factor: goal 100, wish 1000
• Linear reduction (constant reduction factor over the full motion range)
• Simple interface to pusher
• Simple design
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Examples of reduction and amplification mechanisms
Adjustable Strut
Elliptical motion amplifier
Super Amplified Piezoelectric Actuator,
N. Lehrmet, Flux Magazine,
Cedrat-Technologies, Jan. 2000
Application of spring strips to instrument design,
E. M. Eden, Notes of Applied Science No.15, 1956
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Examples of reduction and amplification mechanisms
Flexible Cell for Precision Weighing Scales (Mettler-Toledo)
[E.Hungerbühler et al. (1994), Device for reducing the force in a force measuring apparatus, in particular
a scale, US Patent 5,340,952]
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Working principle
Patent EP06021785 : Henein, S. (2006), Device for converting a first motion into a second motion responsive to
said first motion under a demagnification scale,, Holder: Paul Scherrer Institut
Intermediate Stage
Output Stage
xo
Shim
Input Stage
Converting Blade
x1 0
0
C’
y
A’ A
y1
C
L
y
x 0
B’ B
0
y1
y1 = − 3x12 (5L)
x
x1
x1 ≅ x
3( x + x0 ) 2 3x 2 6 x0
3x02
−
=
x+
y=
5L
5L 5L
5L
Reduction factor:
x 5L
i= =
y 6 x0
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Differential linear conversion
Nanoconverter motions
60
y1, y2, y [microns]
40
y1
y2
y
20
0
-20
-40
-60
-1500
-1000
-500
0
x [microns]
500
1000
1500
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Reduction factor as a function of the offset (e.g. for L=30 mm)
Nanoconverter reduction factor
Reduction factor
1000
500
0
0
200
400
600
800
xo: offset [microns]
ZOOM
1000
1200
1400
Demagnification ratio
110
100
90
80
220
230
240
250
260
xo: offset [microns]
270
280
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Second order error
Effect of the shortening of the acturator blades
Second order motion error (x-x1)/i [Nanometers]
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
-15
-10
-5
0
5
10
Output motion (y) [Microns]
15
20
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1st Version
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1st Version
Main blades
Lenght: 30 mm
Thickness: 0.35 mm
Width: 10 mm
Fixed Outer Frame Output Stage (nano-motion)
Input Stage (micro-motion)
100 mm length
Offset: 0.25 mm
Reduction factor: 100
Material : Stainless Steel
Böhler W720
Manufacturing: Wire-EDM
(Monolithical)
Intermediate Stage Converting Blade
Actuator mounting hole
Grating mounting holes
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Front view
100 mm
Outer frame
Converter blade
Output stage
(fine motion)
Input stage
(coarse motion)
Intermediate stage
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2nd version: wide field-of-view
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Specifications
• Compatible with any commercial linear actuator with a motion range
of ± 1.4 mm, and a force of 40 N
• Fixed reduction factor: i = 100
• Offset: xo = 0.25 mm
• Outer dimensions: 100 x 50 x 10 mm
• Wire-EDM, 2D, monolithical
• Input motion accuracy ± 1 microns
• Output motion range : ± 14 microns
• Output motion accuracy ± 10 nanometers
• Footprint compatible with the Linos Micro & Macro Benches
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Driving force
Elastic restoring forces
50
40
Restoring forces [N]
30
Blades
Preload Springs
Total
Admissible force of springs
Weight
20
10
0
-10
-20
-1500
-1000
-500
0
500
Actuator motion [Microns]
1000
1500
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Swiss-Light-Source Synchrotron Radiation Facility
TOMCAT Beamline: Tomographic Microscopy and Coherent Radiology Experiment (M. Stampanoni)
cSAXS Beamline: Coherent Small Angle X-ray Scattering, (F. Pfeiffer)
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Differential Phase Contrast
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Differential Phase Contrast setup
Differential-Phase-Contrast
Interferometer setup in the SLS
Radiation Facility, TOMCAT
Beamline, Marco Stampanoni
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1st Application: Differential Phase Contrast (DPC) Interferomtery
Differential-Phase-Contrast Setup
Phase gradient image (right) of a human hair with
knot compared to classical absorption image (left)
Trends in synchrotron-based tomographic imaging: the SLS experience, M. Stampanoni et al.,
Proceedings of SPIE, Vol. 6318, Developments in X-Ray Tomography V, Ulrich Bonse, Editor, 2006
| Nanoconverter | S. Henein | Page 18
3D Visualization and Quantification of Angiogenesis
Sample: Melanoma’s metastasis in cervical lymph nodes
Tomographic Reconstruction
Light Microscopy
Pr
ed
t
c
ote
ge
a
im
Blood vessel
150 µm
●
●
Tumoral tissue
Conventional staining for
visual microscopy
Physical slice thickness: 6 µm
●
●
●
●
●
Sample fixed in paraffin
Phase scan @ 17.5 keV, 3rd Talbot distance
Virtual slice thickness : 3.5 µm
Isotropic voxel size: 3.5 µm
Grating Scanning steps 200 nm
F. Marone and M. Stampanoni, TOMCAT in collaboration with R. Marone, University of Basel
| Nanoconverter | S. Henein | Page 19
Conclusion
• Key advantages
• Wide range of reduction factor achievable: typically 20 to 1000
• Linear conversion (reduction factor fixed over the full motion range)
• Planar design (2D), monolihtically manufacturable by EDM, Laser, Etching...etc
• Open issues
• Linearity of the conversion
• Stiffness and dynamical behavior
• Prospects
• Tunable design
• Dedicated actuator (direct screw-nut, cam, piezo... etc)
• High stiffness design based on necked down flexures
• Very wide spectrum of application
| Nanoconverter | S. Henein | Page 20
Acknowledgments
• Brainstorming : P. Boillat
• Detailed drawings : U. Frommherz & M. Vitins
• Manufacturing : Urs Bugmann & Heinrich Blumer
• Testing : M. Riina
• Application (Swiss Light Source, PSI) : M. Stampanoni & F. Pfeiffer
• Contact Person for patent issues: A. Waser (PSI)
• Publication: EUSPEN
[Henein, S. et al. (2007), The Nanoconverter: a novel flexure-based mechanism to
convert microns into nanometers, Proc. of the 7th EUSPEN International Conference, Bremen]
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Thank you for your attention.