Introduction Working principle Classification Construction and working Different types of an optical scope Process capabilities and analysis Testing Process parameters Components and machine structure Confocal laser scanning microscopy Microscopic Advantages Applications Advancement in CMM Machine characteristics Process parameters of CMM Animation video Research papers Bar graphs and tables Conclusion References

1. Shri Ramdeobaba College of Engineering and
Management, Nagpur.
Department of Mechanical Engineering
(2020-21)
OPTICAL MICROSCOPY AND COORDINATE
MEASURING MACHINE
(Micro-CMM)
PRESENTED BY COURSE COORDINATOR
Abhishek Shahu (Roll no.-13) Dr.A.D.Urade
Sangeet Khule (Roll no.-60) (Dept. of Mechanical Engg.)
Sannidhya Shegoankar (Roll no.-61) Course Code : MET 452-6
Mechanical 4th year
1

2. Contents:
● Introduction
● Working principle ● Advantages
● Classification ● Applications
● Construction and working ● Advancement in CMM
● Different types of optical scope ● Machine characteristics
● Process capabilities and analysis ● Process parameters of CMM
● Testing ● Animation video
● Process parameters ● Research papers [7]
● Components and machine structure ● Bar graphs and tables
● Confocal laser scanning microscopy ● Conclusion
● Microscopic ● References 2

3. Introduction:
Optical Microscopy:
● The underlying operating principles for optical microscopes include spatial
resolution determined by the Rayleigh criterion and detected edge sharpness
determined by a combination of hardware e.g.
● Optical microscopes have the advantage of being fast and non-destructive.
● Optical microscopes tend to be repeatable for features as small as 0.25 µm. The
limiting factors for solution of optical metrology hardware are diffraction and the
ability to produce images with dear intensity changes.
● Often locating the edge of a part is difficult, as observed location varies with
lighting condition, noise, and assumptions made in the edge position algorithm.
● Lens type
● CCD camera.
Lighting conditions
● Coastal lighting, Ring lighting
Optical inspection is an
enhancement to simple visual
inspection performed with the
naked eye
Optical measurement refers
to noncontact measurement
using various light sources
3

4. Principle of Optical Microscope :
(Compound Microscope)
● An optical microscope creates a magnified image of an object specimen with an objective lens
and magnifies the image furthermore with an eyepiece to allow the user to observe it by the
naked eye.
● Assuming a specimen as AB in the following figure, primary image (magnified image) A'B' of
inverted real image is created with an objective lens.
Reflected light
4

5. Principle of Optical Microscope :
(Compound Microscope)
● (ob). Next, arrange the eyepiece (oc) so that primary image A'B' is located closer to the
eyepiece than the anterior focal point, then more enlarged erect virtual image A"B" is created.
● Put your naked eye in the eye (pupil) position on the eyepiece barrel to observe the enlarged
image. In short, the last image to be observed is an inverted virtual image.
● As described above, this type of microscope which creates a magnified image by combining an
objective lens making an inverted real image and an eyepiece making an erect virtual image is
called a compound microscope.
● The observation optical system in an optical microscope is commonly standardized on this
compound microscope. Meanwhile, such type of microscope that directly observes an inverted
real image magnified with an objective lens is called a single microscope.
● A microscopic observation on a TV monitor, recently popularized increasingly, uses the way of
directly capturing this inverted real image with a CCD camera, thereby being comprised of a
simple microscope optical system.
5

6. Principle :
Capabilities
● Reflection mode
● Transmission mode
● Raman spectroscopy
Resolution
● Far field optical microscopy
● Resolution = 1/2 µ, about 300 nm
µ : wavelength of light
Near field optical microscopy
● Resolution = the size of the aperture
● Diameter of aperture is 50 - 100 nm, << 1/2 µ
Aluminum triangle islands on glass slides ( 2.5 µm * 2.5 µm ).
6

7. Fig. Optical microscopy image
(A) Raw material of copper (B) 60% RTR
copper (C) 60% CR copper
Fig. The optical ray diagram for (a) transmitted illumination and (b) reflected
illumination.
7

8. Classification of Optical Microscopy :
● There are two basic types of optical microscopes
● Simple microscope ● Compound microscope
8

9. Classification of Optical Microscopy :
● Types of Optical (Incident Light) Microscopes
● Optical microscopes are categorized on a structure basis
according to the intended purpose.
An upright microscope (left photo) which observes a specimen
(object to be observed) from above is widely known as the
most common type with a multitude of uses.
An inverted microscope (right photo) which observes a
specimen from beneath is used for observing the mineralogy
and metallurgy specimens, etc. 9

10. Industrial Microscopes Digital Microscopes :
10

11. Industrial Microscopes Digital Microscopes :
11

12. Figure of Optical Microscopy:
12

13. Optical Microscope Components :
13

14. Optical Microscope Components :
● Eyepiece:
The lens at the top that you look through. It contains 2 or more lenses that focus the
image. Usually has a 10x magnification.
● Turret:
This holds 2 or more objective lenses and can be rotated easily to change magnification
power. Normally when viewing a slide for example, it is best to start the magnification
at the lowest and then work your way upwards.
● Objective:
1 or more objective lens that collect light. The lenses are usually in a cylindrical shaped
tube. The shortest lens has the lowest power i.e the lowest level of magnification, the
longest one is the lens that has the greatest magnification power. The objective lenses
usually have the magnification power 4x, 10x and 40x.
● Focus wheel:
These are wheels that move the stage in the vertical plane. There are also wheels for
adjusting coarse and focus. Some microscopes however, do allow focus at the eyepiece
as well.
14

15. ● Frame:
The frame consists of the arm, the base and is in essence the bodywork of the
microscope. It allows attachment of the focus wheels and the stage to the microscope.
● Light source:
A light source used in place of a mirror. Most microscopes do allow manual light
adjustment via a wheel located near the base.
● Condenser:
The function of the condenser lens is to focus the light onto the specimen. To increase
the quality the condenser lens may also have filters or a diaphragm.
● Stage:
A platform underneath the objective that provides a platform for the slide to be
viewed. In the center of the stage is a hole which allows light to pass through. The
stage also normally has arms to hold the slide in place.
Optical Microscope Components :
15

16. Optical Microscopy :
● Significant errors of optical techniques typically stem from
● An important limitation of optical microscopes for MEMS inspection is the
inability to acquire true three-dimensional data. Some optical microscopes are
integrated with software that uses image processing techniques to determine the
Z-height at which the scan is taking place.
● The current state-of-the-art software uses a projected Ronchi grid to determine the
height at which the microscope is focused in one region of the image.
● If the region selected has multiple focus points (ie, the region selected is not all
on one plane), the algorithms assigns the average value for the Z-height.
● Interference
● Resonance
● Shadowing
● Secondary reflections
● Lens
distortions
16

17. Optical Microscopy :
● Further edge detection algorithms are run to extract X and Y data from the
microscope image. This technique, in theory, produces three dimensional data from an
image
● However, the algorithms used after finding the Z-height in one locations of the image
assume that all of the data are on the same plane.
● Thus, the data acquired from vision systems such as these can be characterized as 2.5-
D data sets.
● Using a stroboscopic method, in-plane dynamic motions can be measured
● However, dynamic measurement of out-of-plane dimensions is difficult.
● Petitgrand and Bosseboeu showed that an optical microscope can be combined with a
phase shifting stroboscopic interferometer to obtain sub-nanometer resolution three
dimensional dynamic measurements.
17

18. Optical Microscopy :
● The resolution (r) is given by the equation proposed by Lord Rayleigh:
where, l is wavelength of light, m is the refractive index of the medium between the
object (specimen) and the objective lens, and a is the semi-angle subtended.
The term msina is also known as the numerical aperture. Using equation, the best
resolution that can theoretically be obtained is in the range 150 to 200 nm.
The performance of any microscope can be understood in terms of two important
parameters: resolution and depth of field.
18

19. Optical Microscopy :
However, the various aberrations in the lenses would make degrade this resolution. The
depth of field is defined as the range of positions for the object (specimen) for which the
eye detects no change in sharpness of the image (see figure 1.2b). The depth of field (h)
is given by:
The depth of field is in the light microscope is of the order of 1 mm. Thus, the depth of
field is very small and therefore, for getting sharp images care has to be taken in sample
preparation. The specimen surface has to be very flat and horizontal.
19

20. Resolving Power :
The resolving power of an optical microscope a is given by the
Abbe equation
Where
● a: distance between two points on the surface of an
object that can be seen separated in the image
plane
● λ: effective wavelength of illumination used
● n: refractive index of objective medium A
● i: suspended angle of lens which depends on its
diameter and focal length 20

21. Optical Microscopy :
● The dimension size is determined by the distance moved
with the x-y stage between the two ends.
● An accuracy level of 1 μm is commonly available with
Abbe's microscopes. Better resolutions are achieved from
interferometric displacement measurement.
● Indeed, dimensions of holes, slots, and other features of
an object less than 200 μm can easily be measured with
accuracy better than 1 μm.
● TMMs are used for dimensional measurement of both
internal and external part features.
21

22. Optical Microscopy Analysis :
Optical microscopy testing capabilities:
● Fixing, Staining and Embedding of Difficult-to-Image Materials
● Expert Microtomy for Thin-section preparation
● Research Microscopy of Surfaces and internal Micro-structures
● Polarised Light Microscopy for identification of Contaminants
● Confocal Microscopy using Molecular Probes and 3D Reconstruction
● Hot-Stage Optical Microscopy Laboratory
● Cold and Shear Stages for altering Sample Micro-environments
● Dynamic Time-lapse Imaging for Fast and Slow events
● Digital Imaging from Macro to Ultra-micro Magnifications
● Fixing, Staining and Embedding of Difficult-to-Image Materials
● Optical Profilometry
● Non-Contact Evaluation of Encapsulated or Multi-component Systems
● Optimisation of Time Dependant variables such as Crystallisation
● Root Cause determination of Product Fracture or Product Failure
● Identification and Measurement of Product Contamination Problem
22

23. Confocal Laser Scanning Microscopy :
● Confocal Laser Scanning Microscopy (CLSM) combines a confocal microscope
with a scanning system in order to gather a three-dimensional data set.
● A CLSM has four basic elements: point illumination, point detection, a confocal
lens system, and a method of scanning the image.
● A typical set-up is shown in Fig.
23

24. Confocal Laser Scanning Microscopy :
● Although scanning can be performed in several different ways, it is most often
done by moving the beam, which alleviates focus problems caused by objective
lens scanning and is faster than specimen scanning.
● Confocal microscopy is different from conventional microscopy in that it creates
an image point by point.
● Also, because of the double pinhole lens system, when the sample is moved out
of the focal plane of the objective, the light intensity at the detector decreases
rapidly, in effect allowing the system to focus on a single plane.
● A different plane can be imaged by moving the detection pinhole. With a
scanning system added, the system has the ability to scan multiple times on
different imaging planes, resulting in a three-dimensional data set.
24

25. Confocal Laser Scanning Microscopy :
● One of the most important advantages found is the ability of the microscope to
measure steep slopes, up to almost 90 degrees on a part with minimal surface
roughness.
● This measurement requires a high-resolution, high-numerical aperture objective,
which has a limited lateral measuring field unsuitable for measuring the entire
object.
● Because of mentioned limitation a stitching procedure is needed to combine scans
taken with several objectives.
25

26. Confocal Laser Scanning Microscopy :
● According to a designed and constructed a single-fiber-optic confocal microscope
a microelectromechanical system (MEMS) scanner and a miniature objective
lens.
● Axial and lateral resolution values for the system were experimentally measured
to be 9.55 μm and with 0.83 μm respectively.
● In good agreement with theoretical predictions reflectance images were acquired
at a rate of 8 frames per second, over a 140 µm x 70 um field-of-view.
● In anticipation of future applications in :
● Oral cancer detection
● Demonstrating the ability of the system to resolve cellular detail 26

27. Microscopic Images :
27

28. Schematic Diagram of CLSM :
28

29. Summary Video for Optical Microscopy :
29

30. Introduction to Micro-CMM :
➢ A coordinate measuring machine is a device that measures the geometry of physical
objects by sensing discrete points on the surface of the object with a probe. Various
types of probes are used in CMMs, including mechanical, optical, laser, and white light.
➢ Depending on the machine, the probe position may be manually controlled by an
operator or it may be computer controlled.
➢ CMMs typically specify a probe's position in terms of its displacement from a reference
position in a three-dimensional Cartesian coordinate system (i.e., with XYZ axes).
➢ In addition to moving the probe along the X, Y, and Z axes, many machines also allow
the probe angle to be controlled to allow measurement of surfaces that would otherwise
be unreachable. 30

31. CMM :
Fig. Coordinate Measuring
Machine
31

32. Micro CMM :
32

33. New Probing Systems :
➢ There are newer models that have probes that drag
along the surface of the part taking points at specified
intervals, known as scanning probes.
➢ This method of CMM inspection is often more
accurate than the conventional touch-probe method
and most times faster as well.
➢ The next generation of scanning, known as non-
contact scanning, which includes high speed laser
single point triangulation,laser line scanning and white
light scanning, is advancing very quickly.
Fig: Motorised automated
probe head with electronic
touch trigger probe
33

34. Probes :
● Micro-CMM measures feature sizes in the range of mm to m. The probe tip should be as small
as possible.
● Two types of probes are necessary, namely the non-contact probe for surface profiling and the
contact probe for edge, steep surface and side wall measurements.
● The principle of non-contact probe is the use of focused laser beam that the spot diameter can be
smaller than 1 m. On the focusing plane the returned light will provide different image from the
out-of-focus planes.
● The key issue of contact probe is the ball tip that has to be made as small as possible while
possessing good sphericity. Its trigger mechanism should be as sensitive and as small contact
force as possible.
34

35. Focus Probe :
● A light from a laser diode is primarily polarised by a grating plate.
Having passed through a beam splitter and a quarter wave plate
(mounted on the beam splitter), it is focused by an objective lens
onto the object surface as a spot approximately 1 Pm in diameter,
about 2 mm from the sensor.
● The reflected beam signal is imaged onto a four-quadrant
photodetector within the sensor by means of the quarter wave
plate.
● The photodiode outputs are combined to give a focus error signal
(FES) that is used to respond to the surface variation. At the focal
plane the spot is a pure circle.
Fig. Optical system of the focus probe
35

36. The variation of spot shape with distance
producing S-curve of FES :
36

37. FES on Various Materials :
37

38. Contact Probe :
● A touch probe is composed of the probe stylus, the probe
mechanism, and the sensor.
● The probe tip must be spherical with diameters ranging from 500
m to 100 m, or less.
● It is normally made by gluing a microball on a micro tungsten
wire. The concentricity of the wire to the ball is a problem in
assembly that will cause measuring error because the probe radius
has to be compensated.
● A technique of fabricating monolithic probe stylus with melting
and solidification processes of a thin glass fibre to form a micro-
sphere tip has been developed.
Fig:
38

39. B. Mechanism of contact probe
C. Setup of touch probe calibration
A. Structure and motion of a touch probe
39

40. Comparison of Macro-CMM and Micro-
CMM :
40

41. Structure of a Micro-CMM :
1 Semi-circular Bridge Structure :
● Rectangular type of the bridge is always employed in the precision CMM
structure for mounting the Z-axis probe.
● In order to meet the high precision requirement in nanometre measurement, the
conventional rectangular bridge shape has to be redesigned so that the stiffness is
higher.
● Therefore, a bridge of semicircular shape is used.
● The deformation at the centre of the bridge is very critical because the self-
weight, the concentrated load from the spindle and the generated driving force
will all act on the bridge.
41

42. Bridge Structures :
42

43. Comparison of Bridge Centre Deflection :
The semi-circular bridge has higher stiffness than the conventionally rectangular type to
almost twice amount.
43

44. Structure of Micro-CMM :
2 Co-planar XY Stage :
► The top table is moved in the X-direction along the precision ground rods
mounted onto the frame, and the frame is moved in the Y-direction along the
precision ground rods of the base.
► The sliding surface of the moving part is mounted with a Teflon pad to reduce the
friction. Four guiding rods are located in the same plane, which means they share
the same vertical height.
► This is the essence of the co-planar stage that the Abbé error in vertical direction
can be significantly reduced.
► In addition, there are no transmission components and the geometry is
symmetrical, which ensures less random error and better static deformation under
the same working conditions.
44

45. Coplanar System :
45

46. Process Capabilities of Micro CMM :
46

47. Advantages :
● The optical CMM offers high geometric accuracy of several optical 3D measurements
in relation to each other, enabling the measurement of small surface details on large
components and precisely determining the position of these individual measurements in
relation to each other.
● The spectrum of measurable surfaces includes all common industrial materials and
composites such as plastics, PCD, CFRP, ceramics, chrome, silicon.
● Simple operation is implemented by single-button solutions, automation and ergonomic
control elements such as a specially designed controller.
● Air-bearing axes with linear drive enable wear-free use and highly accurate, fast
measurements.
47

48. Applications :
The optical high-resolution measurements enable manufactures to verify accuracy
of machining centers and achieve higher reproducibility of processes and products.
48

49. Summary video for CMM :
49

50. Research Papers :
● In this paper, comprehensive review concerning CMMs with capabilities to measure
micro/nano features has been presented.
● This work has also discussed different methods to estimate measurement uncertainty, as well
as performance evaluation of CMMs.
● Moreover, novel concepts such as intelligent CMM, multi-sensor CMM, virtual CMM have
been presented.
● The intelligent CMM would be able to perform all functions automatically such as extraction
of geometric and measuring information of part from its CAD file, selection of probe type,
determination of measuring features, generation of number and coordinates of measuring
points, etc.
● Intelligent planning environment for generating automated CMM inspection should be able
to interpret and extract necessary design information available in CAD model, generate data
structure for inspection plan and identify efficient inspection sequence
Title- New developments in coordinate measuring machines (CMM) for manufacturing industries.
Authors- S. Hammad Mian and A. Al-Ahmari Advanced Manufacturing Institute, College of
Engineering,, King Saud University, Riyadh, Saudi Arabia.: 24 April 2014 published
50

51. Title-3D PRINTING ADDITIVE PROCEDURE MODEL CREATION AND DIMENSIONAL CHECK
USING CMM.
Author- Fakultetska, Zenica,University of Zenica,Faculty of Mechanical Engineering.
Fig: 3D printed model
51

52. Procedure to be Followed :
● The benchmark part is measured on Coordinate measuring machine Zeiss Contura G2.The
measurement plan in CMM software is made by CAD programming, using imported 3D model.
● After importing the model, it is necessary to define coordinate system, domain of measurement
probe movement and measure three referent planes on the model.
● After the workpiece alignment, measurement of all defined features is performed by CMM
scanning in one measurement cycle in CNC mode.
● Sixty different part measurement characteristics are defined in CMM measurement plan for
controlling printing accuracy on the benchmark part.
● The characteristics in CMM software are used for definition of controlled work piece
geometrical dimensions and tolerances and are possible output of a CNC measurement program.
Part features are used for definition,and features measurement results for calculation of
characteristics measurement results.
● The characteristics are grouped in six groups, and those are: flatness,perpendicularity, angularity,
parallelism,cylindricity and diameter cylinder.
52

53. Results :
53

54. Title-Surface and Material Characterization Techniques
Book- Surface Treatment of Materials for Adhesive Bonding
© 2014 Elsevier Inc. All rights reserved.
chapter n.o-4
54

55. Differential Scanning Calorimeter (DSC) :
● Differential scanning calorimetry (DSC) is one of best known techniques in the
group known as the thermal analysis methods.
● Other techniques include differential thermal analysis methods, dynamic
mechanical analysis methods,and thermogravimetric analysis methods
● DSC is a thermal analysis technique used to measure the heat flows related to
transitions in materials as a function of time and temperature.
● These measurements provide qualitative and quantitative information about
physical and chemical changes that involve endothermic or exothermic processes or
changes in heat capacity.
55

56. Conclusion :
● In summary, Tools exist that have exceedingly high resolution, but are limited in range
(i.e. only a few square micrometers can be measured), tools exist that have sufficient
range, but are limited in their ability to measure drastic slope changes on the surface of
the part, a characteristic typical of high aspect ratio micromachined parts.
● The current solution to quantifying micro-scale MEMS parts is to use a combination of
tools. The combination of these techniques, at best, provides geometric information about
localized regions of a specific part, but a technique which provides geometric information
for an entire micromachined part has yet to be realized.
● After doing this research and study about CMM we are able to understand different terms
which are related to micro coordinates measuring machines and we were able to
demonstrate all the required process which are taking place inside the instrument and
capabilities of CMM. 56

57. References :
RESEARCH PAPERS :
● Liang, S., 2004, “Machining and metrology at micro/nano scale,” Keynote speech, In Proceedings of the 1st
International Conference on Positioning Technology,Hamamatsu, Japan, pp. 23–28.
● Sasaki, T., Ishida, K., Teramoto, Kawai, T., and Takeuchi, Y., 2007, “Ultraprecision micromilling of a small 3-D
parts with complicated shape,” In Proceedings of the 7th International Conference of EUSPEN, Bremen,
Germany, pp. 388–391.
● Weckenmann, A., Peggs, G. and Hoffmann, J., 2005, “Probing systems for dimensional micro and nano
metrology,” In Proceedings of International Symposium on Measurement Technology and Intelligent Instruments,
Huddersfield, UK, pp.199–206.
● Claverley, J.D.; Leach, R.K. A review of the existing performance verification infrastructure for micro-
CMMs.Precis. Eng. 2015, 39, 1–15
● Bauza, M.B.; Hocken, R.J.; Smith, S.T.; Woody, S.C. Development of a virtual probe tip with an application to
high aspect ratio microscale features. Rev. Sci. Instrum. 2015, 76, 095112.
● Michihata, M.; Hayashi, T.; Adachi, A.; Takaya, Y. Measurement of Probe-stylus Sphere Diameter for Micro-
CMM Based on Spectral Fingerprint of Whispering Gallery Modes. CIRP Ann. Manuf. Technol.2014, 63, 469–
472.
● https://www.academia.edu/38168355/3D_printing_additive_procedure_model_creation_and_dimensional_check_
using_CMM
57

58. ● http://home.iitk.ac.in/~sangals/virtualLab/microscopyExperiments/microscopyLaboratoryExperiment-1.html
● https://centers.njit.edu/york/analysis/special-microsope.php
● https://www.routledge.com/New-Techniques-of-Optical-Microscopy-and-
Microspectroscopy/herry/p/book/9780849371172
● https://www.olympus-
ims.com/en/microscope/dsx/?gclid=Cj0KCQjw18WKBhCUARIsAFiW7JxFHZn5hucisLyvcHun6exUIS0aRwb75
gWbEvoNP3ABEWJGUza44kYaAgi_EALw_wcB#!cms[focus]=cmsContent14526
● https://www.olympus-ims.com/en/microscope/terms/feature10/
● https://www.intertek.com/analysis/microscopy/optical/
● https://www.slideshare.net/badebhau/measurement-techniques-in-micro-machining-pdf-by-badebhau4gmailcom
● https://www.wikilectures.eu/w/Construction_and_function_of_optical_microscope
● https://en.wikipedia.org/wiki/Optical_microscope
WEBSITES:
References :
58

59. 59

60. 60

61. THANK YOU !
61