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FACULTY AND STUDENTS + Department of Physics, ASU Prof. Nicole Herbots * ,  emeritus Prof. R.J. Culbertson Dr. J. D. Bradl...
FACULTY AND STUDENTS + Department of Physics, ASU Prof. Nicole Herbots*,  emeritus Prof. R.J. Culbertson Dr. J. D. Bradley...
COLLABORATORS Dr. Clive Sell * , MD, vitro-retineal surgeon Dr. Mark Kwong, Chem. Eng., MD, ophtamological surgeon John Mi...
Expertise <ul><li>CONTROL OF SI SURFACES AT THE ATOMIC SCALE </li></ul><ul><ul><li>Creation of  highly planar ordered  sur...
Motivation <ul><li>BIOMEDICAL ENGINEERING </li></ul><ul><li>1.  Cure Medical Complications From Cataracts </li></ul><ul><l...
Outline <ul><li>  1. SCIENTIFIC MODELS & Discoveries </li></ul><ul><li>•  3-D String, RasMol, patents on Si(100) & SiO 2 <...
Nanoscience, materials physics, biophysics, artificial eye-lens & pancreas? <ul><li>Artificial Eyelens Bio-Medical Challen...
SCIENTIFIC MODELS:  Understanding surface  condensation ,  hydroaffinity,  bonding  at the nanoscale …  How do water molec...
How do water molecules  interact with each other or with surfaces? <ul><li>hydrophilic </li></ul><ul><li>hydrophobic </li>...
Medical MOTIVATION #1  How important is this problem? ] Vision at age 40 1 in 5 will develop cataracts 20M Americans have ...
Medical MOTIVATION #1   How important is cataract surgery? Most common surgery in the world  15 million  cataract surgerie...
Motivation  –  access  for all  by removing problem <ul><li>STOP  condensation  on  hydrophobic  IOL </li></ul><ul><li>  <...
SCIENTIFIC MOTIVATION   understanding surface  condensation ,  hydroaffinity  …. And ....  bonding  at the nanoscale   Wha...
x y SCIENTIFIC MOTIVATION understanding surface  condensation ,  hydroaffinity  (attraction to water) …. And ....  bonding...
Ordered Oxide Patent, licensed to Intel <ul><ul><li>Foundational Patent covers </li></ul></ul><ul><ul><li>Herbots-Atluri c...
3.  EXPERIMENTAL PROCEDURES:  Laboratory : No sodium, CLASS 100  clean-room, hoods •  synthesis, contact angle, bonding & ...
•  Chemical Fume and Laminar  Flow Hoods OUTSIDE THE CLEAN ROOM FOR •  experiments on silicone & acrylic IOL’s Use  SALINE...
Hydrophobic Acrylic IOL’s T = 38 °C All  4 IOL’s FOG Within 5 s
How do water molecules  interact with each other or with surfaces? <ul><li>Model System , </li></ul><ul><li>clean-room </l...
EXPERIMENT: MEASUREMENT OF CONTACT ANGLES  Direct Observation of  silicone & acrylic lenses Silicone Lens  Acrylic Lens
EXPERIMENT:  silicone & acrylic lenses’  surface topography  by  Atomic Force Microscopy (AFM) <ul><ul><li>Silicone surfac...
Immediate FOGGING  Observed on BOTH Silicone & Hydrophobic Acrylic IOL’s NO  Fogging After VitreOx on BOTH Silicone & Hydr...
Hydrophobic Acrylic IOL’s T = 38 °C After  VitreOx TM Identical treatment for two different materials!
4. RESULTS:  Two ASU Patents   “Inhibition of condensation on surfaces ..”   (Inter Occular Lenses (IOL’s, etc..) <ul><li>...
What might an artificial pancreas look like?  create an artificial pancreas =  integrate  (1) blood glucose sensor +  (2) ...
The goal is to avoid painful “finger pricks” and CONTINUOUSLY monitor blood chemistry <ul><li>http://www.medtronic-diabete...
The implanted monitor sends  radio-waves  to the  insulin   pump   processor to activate the  alarm  (“ eat ”) or deliver ...
Practically, it boils down to BOND ING: a“Quartz”  Wafer  with  bio-sensors  on it  TO a Silicon  Wafer supporting both   ...
Exploring Nano-Bonding of silicates and Si(100) wafers & dices  <ul><li>Goal  – Direct  Hermetic  *  bond between Si(100) ...
Let’s “NANO-bond!”  = bond at the atomic scale, along crystal “facets” of the silicon crystal Silicon Wafer Quartz  Wafer ...
SCIENTIFIC MOTIVATION:  Understanding surface  condensation ,  hydroaffinity,  bonding  at the nanoscale …  How do water m...
Wet Chemical Processing <ul><li>Wet chemical processing (1) passivate or (2) make Si(100) and SiO 2  surfaces more reactiv...
Wet Chemical Processing of Si(100) <ul><li>(1) Initial Native Oxide </li></ul><ul><li>(2) Hydrocarbon removal </li></ul><u...
Polarization   Properties <ul><li>Contact Area Doubled in Size with  NO  Applied pressure </li></ul><ul><li>Polarization D...
Why Clamping? <ul><li>Surface Roughness </li></ul><ul><ul><li>0.2 nm r.m.s </li></ul></ul><ul><ul><li>Terrace length > 20 ...
4. RESULTS:  Two ASU Patents   “Inhibition of condensation on surfaces ..”   (Inter Occular Lenses (IOL’s, etc..) <ul><li>...
Motivation Scientific background <ul><li>Understanding of Si and SiO 2  surfaces structure & properties </li></ul><ul><li>...
Motivation Scientific background <ul><li>Model </li></ul><ul><ul><li>Deposition of Si and O on a Si(100) substrate creates...
Outer Shell electrons (symbolized by  )  Configuration available for bonding, defect (symbol for missing electron for a co...
<ul><li>2) Oxygen-Silicon-Oxygen-Silicon- Oxygen Atom Chain </li></ul>Method Model Silicone structure: SiO(CH 3 ) 2  is th...
Method Model A Si-O chain with a CH 3  radical attached, the radical can rotate in the plane Defects and mobile charges Po...
<ul><ul><li>Fogging  = nucleation of water droplets + subsequent  interaction to free mobile charges on hydrophobic surfac...
Application  Emergency device during retinal surgery Procedure Fogging DISTORTION Time to Fog (s) VitreOx™ NO NO > 1200 s ...
RESULTS ON DIFFERENT IOL’s Permanent coating on IOL devices Permanent Coating CONDENSATION DISTORSION Time to Time to Fog ...
4. RESULTS:  Two ASU Patents   “Inhibition of condensation on surfaces ..”   (Inter Occular Lenses (IOL’s, etc..) <ul><li>...
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Surface Engineering Research for Bio-Medical & Medical Electronics Applications in 2010: NanoBonding™ and VitreOX™

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This overview of N. Herbots's SiO2 group research on Surface Engineering for Bio-Medical and Medical Electronics in 2010 describes the background to our nest technologies in NanoBonding™ and VitreOX™.

PATENTS & TECHNOLOGY DISCLOSURES RELATED TO THIS RESEARCH:
[1] Methods for Wafer Bonding & for Nucleating Bonding Nanophases Using Wet and Steam Pressurization, N. Herbots, S.D. Whaley, R.Bennett-Kennett, R.J. Culbertson, A.M. Murphy, S.J. Farmer, US Patent filed 10/ 31/2011
[2] Molecular Film Containing Polymeric Mixture for Hydrophobic Implant Surfaces N. Herbots, A, M. Murphy, R. Kennett-Bennett, D.A. Sell S.D. Whaley, R.J. Culbertson, US Patent filed 11/3/ 2011
[3] ASU/AZTE Technology Disclosure M11-163P "H2O Nano-­‐Bonding “ Synthesis via compressive strain from sursaturated water vapor at low temperatures (T< 175°C) of a siloxane-­‐silica mixed nano-­‐bonding phase catalyzed by H2O, nano-scale smoothing and ordering of Si(100) & silica, and room temperature chemical reactivity arising from surface polarization through surface charge generation in SiO2. N. Herbots, S.D. Whaley, R. Bennett-Kennett, R.J. Culbertson, A.M. Murphy, S.J. Farmer, filed June 24th, 2011

[4] ASU/AZTE Technology Disclosure M11-164 P ProteinKnox" - A Temporary and Permanent Surface Bio-Compatible Adsorbate to Control in Conjunction with Hydroaffinity the Blood Proteins Adsorption, Build-up and/or Clot Formation on Surface of Medical Implant Devices and Grafts using LVPL's (Low Viscosity Polar Liquids)" , filed June 24th, 2011

[5] A Method for Wafer Bonding and for Nucleating Bonding Nanophases
N. Herbots, J. D. Bradley, M. Hart, D. A. Sell, S. D. Whaley, R.J Culbertson Provisional Patent Application SN 61/174,138 , ASU/AZTE (filed 3/30/2009).
 
Molecular films for controlling hydrophobic, hydrophilic, optical, condensation and geometricproperties of silicone implants surfaces, including intra-occular lenses used in cataract surgeries. N. Herbots, J. D. Bradley, M. Hart, D. A. Sell & S. D. Whaley
ASU/AZTE (filed 3/30/2009). Provisional patent application filed October 2, 2009
 
Methods for Wafer Bonding and for Nucleating Bonding Nanophases Using Wet and Steam Pressurization, N. Herbots, S.D. Whaley, Ross Bennett-Kennett, R.J. Culbertson, A.M. Murphy, S.J. Farmer, US Patent filed 10/31/11

CONFERENCE PRESENTATIONS
[1] Nanobonding between 2-nm β-crystobalite SiO 2 on OH(1x1)Si(100) & SiO x for Monolithic Electronics by Surface Smoothing via Wet Chemical and Spin Processing: TMAFM Study and Modelling of Interphases “ S.D. Whaley, N. Herbots, J.D. Bradley, R.J. Culbertson, M.A. Hart, D.A. Sell, Q.X. Bradley, R.L.Rhoades, S.N. Drews, R.B. Bennett-Kennett, 58th International American Vacuum Society Symp, Nashville, TN, Oct 31-Nov. 4th, 2011
[2] Controlling the Hydroaffinity of Silicone/Hydrophobic Acrylic Surfaces of Intraocular
Lenses using Visco-Elastic Colloids and Blood Proteins, N. Herbots, R.J. Culbertson, Q.X. Bradley, D.A

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Surface Engineering Research for Bio-Medical & Medical Electronics Applications in 2010: NanoBonding™ and VitreOX™

  1. 1.
  2. 2. FACULTY AND STUDENTS + Department of Physics, ASU Prof. Nicole Herbots * , emeritus Prof. R.J. Culbertson Dr. J. D. Bradley * , Visiting Scientist, Medtronic Corporation Shawn Whaley * & Qian Bradley * , graduate students David Sell* & Murdock Hart, undergraduate Res. Assist, COLLABORATORS Dr. Clive Sell * , MD, vitro-retineal surgeon Dr. Mark Kwong, Chem. Eng., MD, ophtamological surgeon John Mitchell *, Comp. Eng., MBA, CEO Clarizza Watson *, Chem. Eng., MBA, Marketing + Funded by Royalties from US patent 6,613,677 AZ ABOR Tech ASU Strategic Initiative Fund Emeritus College Grant , Bausch & Lomb Donation Associated Retina Consultance. LLC * SiO2 Associates, Founders & Members
  3. 3. FACULTY AND STUDENTS + Department of Physics, ASU Prof. Nicole Herbots*, emeritus Prof. R.J. Culbertson Dr. J. D. Bradley*, Visiting Scientist, Medtronic Corp. Shawn Whaley* & Qian Bradley*, graduate students David Sell* &Murdock Hart, undergr. Res. Assist, Maggie Mitchell, Administrative Assistant
  4. 4. COLLABORATORS Dr. Clive Sell * , MD, vitro-retineal surgeon Dr. Mark Kwong, Chem. Eng., MD, ophtamological surgeon John Mitchell *, Comp. Eng., MBA, CEO Clarizza Watson *, Chem. Eng., MBA, Marketing + Funded by Royalties from US patent 6,613,677 AZ ABOR Tech ASU Strategic Initiative Fund Emeritus College Grant , Bausch & Lomb Donation Associated Retina Consultance. LLC * SiO2 Associates, Founders & Members
  5. 5. Expertise <ul><li>CONTROL OF SI SURFACES AT THE ATOMIC SCALE </li></ul><ul><ul><li>Creation of highly planar ordered surfaces </li></ul></ul><ul><ul><li>Control of surface electrical properties </li></ul></ul><ul><ul><li>Control of hydro-affinity of surfaces </li></ul></ul><ul><ul><li>Creation of hermetic seals by direct atomic bonding </li></ul></ul>
  6. 6. Motivation <ul><li>BIOMEDICAL ENGINEERING </li></ul><ul><li>1. Cure Medical Complications From Cataracts </li></ul><ul><li>stop condensation on hydrophobic lenses during surgery </li></ul><ul><li>How to inhibit condensation on a surface? </li></ul><ul><li>2 . Create Implantable Medical Sensor e.g. an Artificial Pancreas </li></ul><ul><li>bond hermetically silica into an implantable glucose monitor </li></ul><ul><li> How to connect two silica surfaces as if they were one? </li></ul><ul><li>SCIENTIFIC </li></ul><ul><li>understanding surface condensation , hydroaffinity (attraction to water) …. And .... bonding at the nanoscale </li></ul><ul><li>How do water molecules interact with Si, SiO 2 , Silicone, </li></ul><ul><li>acrylics …. Polymers … any material .. </li></ul>
  7. 7. Outline <ul><li>  1. SCIENTIFIC MODELS & Discoveries </li></ul><ul><li>• 3-D String, RasMol, patents on Si(100) & SiO 2 </li></ul><ul><li>• hydrophobic/hydrophilic surfaces of Si(100) & SiO 2 </li></ul><ul><li>2. EXPERIMENTAL PROCEDURES: Laboratories </li></ul><ul><li>clean-room, wet chemical laminar hoods </li></ul><ul><li>• synthesis, contact angle, bonding & condensation </li></ul><ul><li>on Si(100) crystal, SiO 2 , silicone, acrylic lenses, etc… </li></ul><ul><li>topography by Atomic Force Microscopy (AFM) </li></ul><ul><li>composition by Ion Beam Analysis (RBS, PIXE) </li></ul><ul><li>3. RESULTS: 4 ASU Patents, two of which filed on 4/09 and 11/09 </li></ul><ul><li> • “ Wafer bonding using a nanophase connecting both surfaces” </li></ul><ul><li>• “ Inhibition of condensation on surfaces ..” (Inter Occular Lenses) </li></ul>
  8. 8. Nanoscience, materials physics, biophysics, artificial eye-lens & pancreas? <ul><li>Artificial Eyelens Bio-Medical Challenge : </li></ul><ul><li>Modify the surface of a silicone lenticular implant so it </li></ul><ul><li>does NOT “fog” during surgery </li></ul><ul><li>Artificial Pancreas Bio-Medical Challenge </li></ul><ul><li>BOND a blood chemistry monitor (typically on quartz) directly to a single implantable device mounted on silicon wafers. </li></ul>• PHYSICS: Greatest Feat of 20 th Cent. “Contemporary Physics” Unification of Physics & Chemistry [Slater, Feyman] Greatest Feat of the 21 st Century “ New Physics ” : Unification of Physics with Biology?
  9. 9. SCIENTIFIC MODELS: Understanding surface condensation , hydroaffinity, bonding at the nanoscale … How do water molecules interact with surfaces? <ul><li>hydrophilic </li></ul><ul><li>hydrophobic </li></ul>Water molecules are electrical dipoles
  10. 10. How do water molecules interact with each other or with surfaces? <ul><li>hydrophilic </li></ul><ul><li>hydrophobic </li></ul>Water molecules interact with each other as electrical dipoles Water dipoles interact with FREE charges, defects, ions
  11. 11. Medical MOTIVATION #1 How important is this problem? ] Vision at age 40 1 in 5 will develop cataracts 20M Americans have cataracts Cataracts are the leading cause of blindness in the world World Health Organization Everyone will develop cataracts One Cure – Cataract Surgery After Cataract Surgery Most Crystalens Patients Studied 20/40 or Better Bausch & Lomb Early Life Vision <ul><li>Vision at age 65+ </li></ul><ul><li>50% cataract rate </li></ul><ul><ul><li>National Health Institute </li></ul></ul>
  12. 12. Medical MOTIVATION #1 How important is cataract surgery? Most common surgery in the world 15 million cataract surgeries performed each year
  13. 13. Motivation – access for all by removing problem <ul><li>STOP condensation on hydrophobic IOL </li></ul><ul><li> </li></ul><ul><li> </li></ul><ul><li>during secondary </li></ul><ul><li>surgery, after cataract surgery </li></ul><ul><li>LET’s SOLVE THIS PROBLEM! </li></ul>
  14. 14. SCIENTIFIC MOTIVATION understanding surface condensation , hydroaffinity …. And .... bonding at the nanoscale What is “nanoscale “? <ul><li>Interspacing between atoms in a silicon crystal </li></ul><ul><li>or Si(100) surface = 2.5 nm </li></ul><ul><li>hermetically bond a blood chemistry sensor to a processor = </li></ul><ul><li>“ Nanobonding” with with an interphase </li></ul><ul><li> </li></ul>“ Dangling” bonds Quartz Si (100) BEFORE AFTER Quartz Si (100)
  15. 15. x y SCIENTIFIC MOTIVATION understanding surface condensation , hydroaffinity (attraction to water) …. And .... bonding at the nanoscale What is “nanoscale “,  how do water molecules interact ? SiO 2
  16. 16. Ordered Oxide Patent, licensed to Intel <ul><ul><li>Foundational Patent covers </li></ul></ul><ul><ul><li>Herbots-Atluri clean </li></ul></ul><ul><ul><li>Ordered nanophases such as </li></ul></ul><ul><ul><li>ORDERED Si(100) hydroxyl terminated surface, </li></ul></ul><ul><ul><li>results in hydrophobic behavior </li></ul></ul>Passivated Si(100) Surface OH OH OH OH
  17. 17. 3. EXPERIMENTAL PROCEDURES: Laboratory : No sodium, CLASS 100 clean-room, hoods • synthesis, contact angle, bonding & condensation on Si(100) crystal, SiO 2 , silicone & acrylic lenses, - Atomic Force Microscopy (AFM) - surface composition by ion scattering (RBS, PIXE)
  18. 18. • Chemical Fume and Laminar Flow Hoods OUTSIDE THE CLEAN ROOM FOR • experiments on silicone & acrylic IOL’s Use SALINE and Deionized (DI) Water (2 MegOhms, 18 MegOhms)
  19. 19. Hydrophobic Acrylic IOL’s T = 38 °C All 4 IOL’s FOG Within 5 s
  20. 20. How do water molecules interact with each other or with surfaces? <ul><li>Model System , </li></ul><ul><li>clean-room </li></ul><ul><li>• contact angle </li></ul><ul><li>Silicon surface Si(100) </li></ul><ul><ul><li>Hydrophilic Silicon </li></ul></ul><ul><ul><li>Hydrophilic Silicon </li></ul></ul><ul><li>Demonstration of passivated, terminated, ordered Si(100) regions </li></ul><ul><li>Next to a defect rich Si(100) region </li></ul><ul><li>Using metered water drops for contact angle measurements to qualify (1) hydrophobic and (2) hydrophilic behaviors </li></ul>
  21. 21. EXPERIMENT: MEASUREMENT OF CONTACT ANGLES Direct Observation of silicone & acrylic lenses Silicone Lens Acrylic Lens
  22. 22. EXPERIMENT: silicone & acrylic lenses’ surface topography by Atomic Force Microscopy (AFM) <ul><ul><li>Silicone surface is very smooth (Optically Superior) </li></ul></ul><ul><ul><li>Acrylic surface is rougher </li></ul></ul>
  23. 23. Immediate FOGGING Observed on BOTH Silicone & Hydrophobic Acrylic IOL’s NO Fogging After VitreOx on BOTH Silicone & Hydrophobic Acrylic IOL’s T = 38 °C Hydrophobic Acrylic IOL’s
  24. 24. Hydrophobic Acrylic IOL’s T = 38 °C After VitreOx TM Identical treatment for two different materials!
  25. 25. 4. RESULTS: Two ASU Patents “Inhibition of condensation on surfaces ..” (Inter Occular Lenses (IOL’s, etc..) <ul><li>Dr. Clive Sell, MD smiles as he applies our bio-compatible treatment, “VITREOX” to render an IOL hydrophilic. </li></ul><ul><li>He has used the technique successfully </li></ul>
  26. 26. What might an artificial pancreas look like? create an artificial pancreas = integrate (1) blood glucose sensor + (2) monitoring electronics hermetically into a single implantable device How to connect two silica surfaces as if they were one?
  27. 27. The goal is to avoid painful “finger pricks” and CONTINUOUSLY monitor blood chemistry <ul><li>http://www.medtronic-diabetes.com.au/images/launch/diagram_02.jpg </li></ul>create an artificial pancreas = integrate (1) blood glucose sensor + (2) monitoring electronics hermetically into a single implant device How to connect two silica surfaces as if they were one?
  28. 28. The implanted monitor sends radio-waves to the insulin pump processor to activate the alarm (“ eat ”) or deliver insulin (“ fast ”)
  29. 29. Practically, it boils down to BOND ING: a“Quartz” Wafer with bio-sensors on it TO a Silicon Wafer supporting both microprocessor and a radio emitter which means BONDING a wafer of Silicon Oxide , SiO 2 (= glass) to a Silicon wafer called Si(100) because of its “facet” => We are really researching Direct Nanobonding Between Si(100) and SiO 2 *
  30. 30. Exploring Nano-Bonding of silicates and Si(100) wafers & dices <ul><li>Goal – Direct Hermetic * bond between Si(100) and SiO 2 surfaces </li></ul><ul><li>Experimental Design </li></ul><ul><ul><li>Wet Chemical Processing </li></ul></ul><ul><ul><li>Clamping </li></ul></ul><ul><ul><li>Annealing to induce bonding </li></ul></ul><ul><li>Observation & Results </li></ul><ul><li>* Hermetic means NO LEAKING, NO CORROSION IN THE HUMAN BODY/SALINE SOLUTION ! </li></ul>
  31. 31. Let’s “NANO-bond!” = bond at the atomic scale, along crystal “facets” of the silicon crystal Silicon Wafer Quartz Wafer Silicon Wafer Quartz Wafer BEFORE AFTER
  32. 32. SCIENTIFIC MOTIVATION: Understanding surface condensation , hydroaffinity, bonding at the nanoscale … How do water molecules interact with Si, SiO 2 ? <ul><li>SiO 2 surfaces are very stable, hydrophobic </li></ul><ul><li>Etching creates dangling bonds on the SiO 2 surface, </li></ul><ul><li>renders hydrophilic </li></ul><ul><li>Si(100) is initially hydrophilic , very reactive </li></ul><ul><li>Our 6,613,677 patent passivates Si(100) with OH termination & renders it hydrophobic </li></ul>
  33. 33. Wet Chemical Processing <ul><li>Wet chemical processing (1) passivate or (2) make Si(100) and SiO 2 surfaces more reactive. </li></ul><ul><li>Herbots-Atluri process passivates Si(100) with OH-like groups (see ABOR US patent 6.616,677 (9/3/03) </li></ul><ul><li>Explore wet chemical processing to nucleate & grow nanophases across Si(100) /SiO 2 interfaces </li></ul>Passivated Si(100) Surface OH OH Reactive Surface OH OH
  34. 34. Wet Chemical Processing of Si(100) <ul><li>(1) Initial Native Oxide </li></ul><ul><li>(2) Hydrocarbon removal </li></ul><ul><li>(3) Aqueous HF etch </li></ul><ul><li>(4) Chemical oxide and planarization </li></ul><ul><li>(5) Oxide strip </li></ul><ul><li>(6) Silanol (OH) termination </li></ul><ul><ul><li>Passivated but ready to react </li></ul></ul>18 MegOhms Deionized (DI) Water rinse between each step for 10 minutes
  35. 35. Polarization Properties <ul><li>Contact Area Doubled in Size with NO Applied pressure </li></ul><ul><li>Polarization Due to Oxygen Deficient Oxide </li></ul><ul><li>Mixed Cleans Used to Maximize Effect </li></ul>
  36. 36. Why Clamping? <ul><li>Surface Roughness </li></ul><ul><ul><li>0.2 nm r.m.s </li></ul></ul><ul><ul><li>Terrace length > 20 nm </li></ul></ul><ul><li>Warp </li></ul><ul><ul><li>A+B < 30 microns </li></ul></ul><ul><li>Thickness Variation </li></ul><ul><ul><li>A+B < 25 microns </li></ul></ul><ul><li>Herbots-Atluri clean smoothens surface from 2 nm to 20 nm terraces </li></ul>Clamped Surface
  37. 37. 4. RESULTS: Two ASU Patents “Inhibition of condensation on surfaces ..” (Inter Occular Lenses (IOL’s, etc..) <ul><li>Dr. Clive Sell, MD smiles as he applies our bio-compatible treatment, “VITREOX” to render an IOL hydrophilic. </li></ul><ul><li>He has used the technique successfully </li></ul>
  38. 38. Motivation Scientific background <ul><li>Understanding of Si and SiO 2 surfaces structure & properties </li></ul><ul><li>Silicon surface </li></ul><ul><ul><li>After cleaning and passivation (inhibit further oxidation), dangling bonds are terminated resulting in hydrophobic behavior if the surface is “ordered” </li></ul></ul><ul><ul><li>Defects on the surface may act like nucleation sites for water condensation </li></ul></ul><ul><li>Silicon with SiO 2 thin layer </li></ul><ul><ul><li>Alter surface from hydrophobic to hydrophilic using Herbots-Aturi clean, then grow a SiO 2 thin layer </li></ul></ul><ul><li>Demonstration of passivated, terminated, ordered Si(100) regions </li></ul><ul><li>Next to a defect rich Si(100) region </li></ul><ul><li>Using metered water drops for contact angle measurements to qualify (1) hydrophobic and (2) hydrophilic behaviors </li></ul>
  39. 39. Motivation Scientific background <ul><li>Model </li></ul><ul><ul><li>Deposition of Si and O on a Si(100) substrate creates an SiO 2 thin layer </li></ul></ul><ul><ul><li>Silicon oxide reactive surface results in the hydrophilic behavior </li></ul></ul>x y
  40. 40. Outer Shell electrons (symbolized by ) Configuration available for bonding, defect (symbol for missing electron for a complete shell ) Building a Silicone Molecule Carbon has polymorphic phases, flexibility in bonds - + Oxygen Silicon Carbon Hydrogen More directional, single phase, only one kind of rigid bonding Strongly electronegative in the outer shell With 6 negatively charged electrons - Hydrogen is a strong electron donor
  41. 41. <ul><li>2) Oxygen-Silicon-Oxygen-Silicon- Oxygen Atom Chain </li></ul>Method Model Silicone structure: SiO(CH 3 ) 2 is the building block (monomer) 1) First chemical building block Si-O atom pair 3) Si-O atom pair with electron configuration and bonding sites (a) Before bonding (b) After bonding 4) Backbone of the silicone chain Si-O-Si-O-Si-O-Si-O. showing the sites Available for bonding CH 3
  42. 42. Method Model A Si-O chain with a CH 3 radical attached, the radical can rotate in the plane Defects and mobile charges Polydimethylsiloxane PDMS Silicone
  43. 43. <ul><ul><li>Fogging = nucleation of water droplets + subsequent interaction to free mobile charges on hydrophobic surface </li></ul></ul><ul><ul><li>Ostwald ripening = droplets enlarges with time, small droplets combine to bigger droplets to minimize area to volume ratio & surface energy </li></ul></ul>To Understand and inhibit condensation on Silicone surface
  44. 44. Application Emergency device during retinal surgery Procedure Fogging DISTORTION Time to Fog (s) VitreOx™ NO NO > 1200 s (20 min) + Healon® YES YES 290 s Viscoat® YES YES 10 s Wiping YES YES 5 s Natural YES YES 3 s
  45. 45. RESULTS ON DIFFERENT IOL’s Permanent coating on IOL devices Permanent Coating CONDENSATION DISTORSION Time to Time to Fog (seconds) Silicone IOL Preserved in air NO NO 1200 seconds + = 20 minutes + Silicone IOL Preserved in saline NO NO Ongoing Trials Hydrophobic acrylic IOL Preserved in saline NO NO Ongoing Trials
  46. 46. 4. RESULTS: Two ASU Patents “Inhibition of condensation on surfaces ..” (Inter Occular Lenses (IOL’s, etc..) <ul><li>Dr. Clive Sell, MD smiles as he applies our bio-compatible treatment, “VITREOX” to render an IOL hydrophilic. </li></ul><ul><li>He has used the technique successfully </li></ul>

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