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

2. Powder Formulation Components PCL: polycaprolactone PCL: polycaprolactone C 6 H 10 O 2 C 6 H 10 O 2 PLGA: poly(lactide-co-glycolide) PLGA: poly(lactide-co-glycolide) (C 6 H 8 O 4 ) x (C 4 H 4 O 4 ) y (C 6 H 8 O 4 ) x (C 4 H 4 O 4 ) y TCP: tricalcium phosphate TCP: tricalcium phosphate Ca 3 (PO 4 ) 2 Ca 3 (PO 4 ) 2 HA: hydroxyapatite HA: hydroxyapatite Ca 5 (PO 4 ) 3 OH Ca 5 (PO 4 ) 3 OH

3. Update from Formal Design Review Modulus ranges for individual materials Modulus ranges for individual materials PCL: 0.5-1 GPa PCL: 0.5-1 GPa PGA: ~8 GPa PGA: ~8 GPa PLA: 2-3 GPa PLA: 2-3 GPa HA: 7-13 GPa HA: 7-13 GPa Modulus for scaffold structures Modulus for scaffold structures ~0.001 GPa ~0.001 GPa

4. Initial Goals Characterize current composition Characterize current composition 30% sucrose 30% sucrose 30% lactose 30% lactose 20% TCP 20% TCP 20% PLGA 20% PLGA Solid structures Solid structures

5. Solidworks Test Samples Drew up SolidWorks files Drew up SolidWorks files Printed tension specimens Printed tension specimens Compression Tension

6. Mechanical Testing Used Yin Lin’s Instron Used Yin Lin’s Instron Automatic grips Automatic grips Controlled by air pressure Too high Manual grips Manual grips Work for our samples Noisy, inaccurate data

7. Young ’ s Modulus: E = Estress/Estrain = 280 KPa Young ’ s Modulus: E = Estress/Estrain = 280 KPa Failure Stress = 26.6 KPa Failure Stress = 26.6 KPa Yield Stress = 20.9 KPa Yield Stress = 20.9 KPa Engineering Stress = force/area Engineering Stress = force/area Engineering Strain = displacement / original length Engineering Strain = displacement / original length Instron Test Results

8. Future Mechanical Testing Candidates Look at different methods of testing Look at different methods of testing Nanoindentation Nanoindentation Problematic microstructure Problematic microstructure Would need too large of an indenter Would need too large of an indenter 3- or 4- point bending tests 3- or 4- point bending tests Will not reduce materials usage Will not reduce materials usage MicroTester Instron MicroTester Instron Best option Best option

9. MicroTester Instron Mechanical Testing MicroTester benefits MicroTester benefits Smaller load cell (10N) Smaller load cell (10N) Smaller sample size = less materials and printing time Smaller sample size = less materials and printing time Automated as opposed to manual Automated as opposed to manual Made appt. to test next week (thanks to Alan Schwartzman) Made appt. to test next week (thanks to Alan Schwartzman)

10. SEM Imaging

11. X-Ray Spectra PGLA Tricalcium Phosphate

12. Additional Progress Polymer dispersion process Polymer dispersion process Started on PCL Started on PCL Received HA order Received HA order Placed order for beta- TCP Placed order for beta- TCP

13. Next Steps Test more samples Test more samples Tension and compression Tension and compression A range of formulations (using HA) A range of formulations (using HA) SolidWorks test files for MicroTester SolidWorks test files for MicroTester MicroTester testing MicroTester testing Waffle structure in test specimens Waffle structure in test specimens

14. Project Timeline

15. Questions?