1. STEREOLITHOGRAPHY Chris Hannigan Joe McCullough

2. WHAT IS IT?  Additive Manufacturing Process  Rapid Prototyping  First method of rapid prototyping developed by 3D Systems  Patented in 1986 by Chuck Hull http://www.futuristspeaker.com/2012/02/2- billion-jobs-to-disappear-by-2030/ http://www.micromoldcorp.com/RPRO/Frame2Aa.html

3. HOW DOES IT WORK? http://www.custompartnet.com/wu/stereolithography

4. CURING PROCESS  Liquid Photopolymer  Acrylic monomer  determines properties  Photoinitiators  Curing agent  Oligomer  Small monomer used to bond  UV Laser  Cures by wavelength  Typically 320 - 360 nm  Blade Jacobs, Paul F. Rapid prototyping & manufacturing: fundamentals of stereolithography. Sme, 1992 http://www.warnlaser.com/Laser_pointer/500m w-200mw-100mw-50mw-uv-violet-laser-pointer- razor-series

5. POST-CURING  “Green” parts only cured 80-96%  Gaussian Energy Distribution  Post curing apparatus needed for further solidification  Ultraviolet chamber: 300 Watts  Microwave oven: 700 Watts  Thermal oven: 125˚C [1] http://wired.wikidot.com/uv-lightbox

6. DISADVANTAGES  Cost  Initial  $100,000 -$400.000  Resin  $300 per gallon  Shrinkage  Inaccuracies can occur during any phase  Tolerance must be monitored  Size of model  Low volume output

7. ADVANTAGES  Functional Prototype  Comparatively fast  Material Efficiency  Excellent Surface Finish http://www.materialise.co.jp/giant-prototypes

8. FUTURE OUTLOOK  Specific medical devices  Improvements in accuracy  Desktop Stereolithography  $3,299 http://www.kickstarter.com/projects/formlabs/form-1-an-affordable-professional-3d-printer

9. PRINTED GUNS???? http://thekneeslider.com/rapid-prototypes/ http://info-rapidprototyping.blogspot.com/2009_02_15_archive.html

10. REFERENCE  [1]Salmoria, G.V., C.H. Ahrens, V.E. Beal, A.T.N Pires, and V. Soldi. "Evaluation of Post-curing and Laser Manufacturing Parameters on the Properties of SOMOS 7110 Photosensitive Resin Used in Stereolithography." Materials & Design 30.03 (2009): 758-63. Science Direct. Web