Rosa alejandra lukaszew a review of the thin film techniques potentially ap...thinfilmsworkshop
SRF is a surface phenomenon where only ~10 penetration depths are needed (l=40 nm for niobium), thus it has been recognized for some time now that it would be economically convenient to use thin film coated cavities. But problems arise with defects within 1 or 2 l of the surface or on the surface, and insufficient attention has been paid to this topic, including trapping of impurities like oxygen in defects as well as surface roughness enabling magnetic field pinning sites. Earlier attempts at CERN applied standard sputter PVD methods, but the grain size for the CERN Nb/Cu films was 100 nm, which is 10,000 times smaller than for conventional SRF cavities with the ensuing problems that appear at grain boundaries. Thus, these prior attempts showed higher surface resistance and worst Q-slope than bulk. I will review more modern approaches using higher energetic PVD methods for thin film deposition which offer promise to achieve thin films with improved superconducting performance.
Bioceramic dental implant coatings (Deposited and converted coatings ).
This presentation discusses the different techniques used to coat dental implants to enhance osseointegration .
Rosa alejandra lukaszew a review of the thin film techniques potentially ap...thinfilmsworkshop
SRF is a surface phenomenon where only ~10 penetration depths are needed (l=40 nm for niobium), thus it has been recognized for some time now that it would be economically convenient to use thin film coated cavities. But problems arise with defects within 1 or 2 l of the surface or on the surface, and insufficient attention has been paid to this topic, including trapping of impurities like oxygen in defects as well as surface roughness enabling magnetic field pinning sites. Earlier attempts at CERN applied standard sputter PVD methods, but the grain size for the CERN Nb/Cu films was 100 nm, which is 10,000 times smaller than for conventional SRF cavities with the ensuing problems that appear at grain boundaries. Thus, these prior attempts showed higher surface resistance and worst Q-slope than bulk. I will review more modern approaches using higher energetic PVD methods for thin film deposition which offer promise to achieve thin films with improved superconducting performance.
Bioceramic dental implant coatings (Deposited and converted coatings ).
This presentation discusses the different techniques used to coat dental implants to enhance osseointegration .
The presentation covers all the methods of Rapid protoyping and various aspects related to it.
The Topics covered in the presentation are
1) Droplet Deposition Manufacturing
2) Laminated Object Manufacturing
3) Fused Deposition Modeling
4) Selective Laser Manufacturing
5) Sterolithography
This paper explains the fabrication of thin film using modified Physical Vapor Deposition (PVD) Module. Physical Vapor Deposition (PVD) is a variety of vacuum deposition and is a general term used to describe any of a variety of methods to deposit thin films by the condensation of a vaporized form of the material onto various surfaces. The surface morphology of various such as Titanium Dioxide and Aluminum thin film has been studied. The Titanium Dioxide and Aluminum thin film has been fabricated on Silicon (Si) substrate using modified Physical Vapor Deposition (PVD) module system. The process started with the establishment of process flow, process modules, and process parameters. Two modules were developed. The characteristics prior to the thin film fabrication namely surface morphology, metal thickness characterization and V-I characteristic were recorded. The samples were characterized by Optical Microscope, Atomic Force Microscope (AFM),X-ray diffraction (XRD) and I - V characterization. The result and data were analyzed and applied in the fabrication of thin film using various materials. The thin film fabrication process used Titanium Dioxide (TiO2) nanopowder and Aluminum (Al2O3) nanopowder for the coating process. The result for each processes are presented in this paper.
Nanotechnology and its Economic FeasibilityJeffrey Funk
These slides apply the concepts from my course (Analyzing Hi-Tech Opportunities) to the field of nano-technology. Like the reductions in the feature sizes of transistors and metal lines on ICs (integrated circuits), in the micro-fluidic channels on bio-electronic ICs, and in the features of MEMS (micro-electronic mechanical systems), many physical phenomena become pronounced as the feature size decreases. Carbon nano-tubes, grapheme, quantum dots, nano-particles, and nano-fibers are examples of materials that benefit from small sizes. On the other hand, reductions in costs must be addressed through increases in the scale of production equipment and the creation of better processes; similar things occurred with other technologies such as displays and lighting.
Advanced Materials International Forum, Bari 18-19 settembre, conferenza internazionale dedicata ai materiali avanzati e alle loro possibili applicazioni nei settori industriali, con un focus particolare sui trasporti (aerospazio, automotive, navale e cantieristico).
A Multiscale Simulation Approach for Diesel Particulate Filter Design Based o...Ries Bouwman
The majority of Diesel exhaust gas aftertreatment system design and development
work is done experimentally by means of long and expensive engine bench tests.
The final system configuration is generally the product of a series of experimental
“trial and error” operations. In order to shorten the development process, to reduce
testing costs and to increase the durability of Diesel Particulate Filters (DPFs), multidisciplinary
simulation tools are needed to predict possible failures of the DPF.
Recently, several numerical models have been developed to simulate globally the
soot loading capacity, the pressure drop evolution and the regeneration behaviour in
ceramic wall-flow filters. Less effort has been devoted to the development of
dedicated models for the simulation of the microstructural flow phenomena and
thermo-mechanical behaviour of the filters.
This paper describes the development of a multi-physics software tool based on
OpenFOAM embedded in the DexaSIM Graphical User Interface (GUI) which is able
to handle the evolution of microstructural material properties and complex physical
phenomena inside the filter material as well as response of complete filters under
engine operating conditions.
The modelling approach hence builds on the multiscale link between microstructural
evolution and specific macroscopic exhaust system features with the objective to
achieve major improvements in material design and lifecycle assessment.
5. Processing Hardware
Process stations are graphite crucibles
Sublimation used to deposit material
Benefits:
High material utilization
Moderate temperatures and vacuum levels
required
High quality films produced rapidly
Challenges:
Film uniformity driven by thermal uniformity
and hardware geometry
Deposition hardware costly to machine
7. Modeling Approach
Thin-Film Processing Hardware
Modeling Difficulties:
Deposition and condensation surface chemistry
Low pressure physics must be accounted for at 40mTorr
Flow at walls require special consideration
8. Sublimation and condensation are the two dominant reactions that take place
Arrhenius rate equation used by Fluent
Sc: Sticking coefficient
Calculated after experiments
A: Pre-exponential factor
Calculated for each reaction
EA: Activation energy
β: Temperature exponent
R: Universal gas constant
T: Temperature
Modeling Approach
Thin-Film Processing Hardware
9. Modeling Results
Thin-Film Processing Hardware
Cd gas molar fraction in the pocket Cd growth rate on the substrate (kg/m2s)
Vapor distribution and film uniformity can be analyzed
10. Modeling Results
Thin-Film Processing Hardware
Simulation-based engineering analysis provides otherwise unobtainable insight
Flow lines colored by Cd
molar fraction
11. Experimental Validation
Thin-Film Processing Hardware
Results validated by comparing modeled
and deposited film thicknesses
Scanning White Light Interferometry
Sticking coefficient applied from initial
experiments
12. Experimental Results
Thin-Film Processing Hardware
Modeled film thickness correlates
strongly with experimental results
Validated model used to improve new
source design before production
13. Hardware Design Improvement
Model used to predict film growth
Same equations and boundary conditions
Different geometry
Improved film uniformity
Deeper pocket
Shallower wells
Gen 1 Gen 2
1st Generation
2nd Generation
14. Hardware Redesign Results
The model predicts that the 2nd Generation source should produce more
uniform films
1st Generation
Contours of CdS film thickness: Each line represents a 1% change in thickness
2nd Generation
15. Hardware Redesign Results
Film uniformity experimentally matches predicted values
Uniformity improved by over 70% with one design iteration
1st Generation 2nd Generation
16. Continuing Work
Modeling different thin-film material evaporation processes
CdS
CdTe
CuCl
CdCl2
Deposition Rates in
(nm/s)
18. Thin Film Product Operation
New thin-film PV module design:
Designed for UV and moisture
resistance
No lamination or batching
required
Small factory footprint
Patent pending
Source: Nordson.com
19. Prototype Architecture
Two panes of custom made glass
1200 x 600 x 3.2mm each
2+ encapsulating polymers with additives
Air gap between glass panes
3μm thick semiconductor film
Top Glass
Bottom Glass
Silicone PIB Low cost polymer /
desiccant
CdTe Film
Desiccated
gap
X-section of module edge
20. Modeling Approach
Thin Film Product Operation
Over 3 million elements used
Convection boundary conditions
obtained from 2D model
Film represented as surface
Wind velocity
(m/s)
21. Modeling Approach
Thin Film Product Operation
Radiation heat transfer must be considered
Real world solar spectrum used
Unique, wavelength-based quantum efficiency of
the device accounted for
22. Prototype and industry-standard
devices modeled and compared
Numerous convection and radiation
conditions queried
Operating matrix created to analyze
thermal response trends
Modeling Results
Thin Film Product Operation
Film temperature (K)
23. Experimental Results
Thin Film Product Operation
Both devices thermal response observed
Real-world solar and wind conditions
measured at nearby station
Experimental conditions input as boundary
conditions for model
Experimental results match modeled values
24. Conclusion
Method for modeling thin-film processing demonstrated
Method can be used to improve hardware before manufacturing
Thin-film product operation in real-world conditions modeled
Simulation is valuable for thin-film processing and product design
before manufacturing