1. Fast Casters – Project Update February 16, 2006 Rene Chen Byron Hsu Kimberly Kam Kelsey Vandermeulen Lisa Witmer

2. Objectives Progress since last update Progress since last update New project candidates New project candidates Technology of speed skate blade Technology of speed skate blade 3-D printing of bone scaffolding 3-D printing of bone scaffolding

3. Important Material Characteristics in Speed Skates Strong, resistant to wear Strong, resistant to wear Low thermal conductivity Low thermal conductivity Able to be sharpened Able to be sharpened

4. Titanium vs. Steel Blade + Increased durability + Needs to be sharpened less often - Sharpening takes time and may dull the tools SteelTitanium Thermal Conductivity [W/m-K] 15.26.7 Hardness, Vickers 153349 Cost [USD/lbs.] $0.18$4.50

5. Challenges Analyzing advantages and difficulties of using a titanium blade Analyzing advantages and difficulties of using a titanium blade Analyzing advantages of casting over forging or water jet cutting Analyzing advantages of casting over forging or water jet cutting Finishing the blade Finishing the blade

6. 3D Printing of Hydroxyapatite Bone Scaffolds Objective Objective 3D porous hydroxyapatite scaffold for bone replacement customized from patient’s CT scans Seitz et al, Wiley Periodicals

7. CT scan from patient CAD image of bone replacement The Process Bone scaffold fabricated from 3D printer Surgeons implant customized scaffold into patient

8. Requirements of HA Bone Scaffolds Porosity Porosity Strength Strength Interconnected channels Interconnected channels Channel size Channel size Biocompatibility Biocompatibility Bone ingrowth Bone ingrowth Seitz et al, Wiley Periodicals

9. Hydroxyapatite Ca 10 (PO 4 ) 6 (OH) 2 Ca 10 (PO 4 ) 6 (OH) 2 Chemically similar to the component of bones Chemically similar to the component of bones Supports bone ingrowth Supports bone ingrowth Biodegrades in the body over time Biodegrades in the body over time HA in powder form HA in powder form

10. Why HA Bone Scaffolds Would Benefit from 3D Printing Rapid prototyping Rapid prototyping Quick customization using CT scan of patient Quick customization using CT scan of patient Complexity of scaffold Complexity of scaffold Leukers et al, Journal of Mat. Sci.

11. Challenges of 3D Printing Hydroxyapatite Scaffolds HA particle size HA particle size Acceptable binder Acceptable binder polymeric polymeric Small enough size resolution Small enough size resolution Time constraints Time constraints Sintering Sintering Shrinkage Shrinkage Cell culture Cell culture

12. The Game Plan Explore different combinations of hydroxyapatite and biocompatible materials Explore different combinations of hydroxyapatite and biocompatible materials Uniaxial tension/compression tests Uniaxial tension/compression tests SEM imaging of microstructure SEM imaging of microstructure Different channel geometries Different channel geometries

13. Questions/Comments?

14. Backup/Extra Information

15. Material Candidates Spray-dried hydroxyapatite granulates with polymeric additives V5.2 and V12 Polymeric binder Schelofix dissolved in water (10 and 14wt%) Hermann Seitz, “Three-Dimensional Printing of Porous Ceramic Scaffolds for Bone Tissue Engineering”, Wiley Periodicals, 2005. Hermann Seitz, “Three-Dimensional Printing of Porous Ceramic Scaffolds for Bone Tissue Engineering”, Wiley Periodicals, 2005.