Micro-particle Fabrication For Tissue Engineering Applications Using Rapid Prototyping And Soft Lithography Principles 1 W...
Overview <ul><li>Motivation / Design Goal </li></ul><ul><li>Rapid Prototyping micro-particle fabrication </li></ul><ul><li...
Motivation / Design Goal <ul><li>Soft Lithography currently in wide use in tissue engineering </li></ul><ul><ul><li>Micro-...
Rapid Prototyping  <ul><li>Microparticles designed as two dimensional architectures extruded in the third dimension </li><...
Soft Lithography * Poly(dimethylsiloxane) #  Poly(propylene fumarate) di-ethyl fumarate Glass PDMS Mold PPF-DEF # Place in...
Printing Considerations <ul><li>Best plotter path selected for optimum shape replication  </li></ul><ul><li>Extruded rim m...
Photolithographic Transfer <ul><li>Successive geometric complexity increased part error and reduced clarity of geometry </...
Morphological Analysis <ul><li>Dimensional measurement of steps leading to production of final microparticles </li></ul><u...
Conclusions <ul><li>Microparticles built repeatably with conservation of architecture </li></ul><ul><ul><li>Average of 98....
Future Directions <ul><li>Future Directions  </li></ul><ul><ul><li>Development of compensation algorithm to allow for crea...
Acknowledgements <ul><li>Molly Mullican and Chris Chen for microparticle work </li></ul><ul><li>Chris Chen for rapid proto...
Upcoming SlideShare
Loading in...5
×

Micro-Particle Fabrication For Tissue Engineering Applications Using Rapid Prototyping And Soft Lithography Principles, 6/2005

1,385

Published on

Presentation given to the American Society of Mechanical Engineers, 6/2005

ABSTRACT
The goal of this study was to develop an efficient and repeatable process for fabrication of micro-particles from multiple materials using rapid prototyping and soft lithography. Phase change three-dimensional printing was used to create masters for PDMS molds. A photocrosslinkable polymer was then delivered into these molds to fabricate geometrically complex three-dimensional micro-particles. This repeatable process has demonstrated the ability to generate micro-particles with greater than 95% repeatability with complete pattern transfer. This process was illustrated for three shapes based on the extrusion of two-dimensional shapes. These particles will allow for tailoring of the pore shapes within a porous scaffold utilized in tissue engineering applications. In addition, the different shapes may allow control of drug release by varying the surface to volume ratio, which could modulate drug delivery. While soft lithography is currently used with photolithography, its high precision is offset by high cost of production. The employment of rapid prototyping to a specific resolution offers a much less expensive alternative with increased throughput due to the speed of current rapid prototyping systems.

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
1,385
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
0
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Transcript of "Micro-Particle Fabrication For Tissue Engineering Applications Using Rapid Prototyping And Soft Lithography Principles, 6/2005"

  1. 1. Micro-particle Fabrication For Tissue Engineering Applications Using Rapid Prototyping And Soft Lithography Principles 1 Wettergreen MA, 2 Scheffe J, 1 Mikos AG, 1 Liebschner MAK 1 Department of Bioengineering, Rice University 2 Department of Chemical Engineering, Colorado University
  2. 2. Overview <ul><li>Motivation / Design Goal </li></ul><ul><li>Rapid Prototyping micro-particle fabrication </li></ul><ul><li>Soft Lithographic molding technique </li></ul><ul><li>Morphological analysis </li></ul>
  3. 3. Motivation / Design Goal <ul><li>Soft Lithography currently in wide use in tissue engineering </li></ul><ul><ul><li>Micro-fluidics, stamping, spatial patterning of cells, biomaterials </li></ul></ul><ul><li>Silicon masters are versatile in usage </li></ul><ul><ul><li>Masters are inert, sterilizable, and optically clear </li></ul></ul><ul><ul><li>Resuable with conservation of high resolution features </li></ul></ul><ul><li>Master generation is cost and time prohibitive </li></ul><ul><ul><li>Complex patterns not easily manufactured </li></ul></ul><ul><ul><li>Silicon plates are fragile and expensive </li></ul></ul><ul><li>Cost reductive processes being explored </li></ul><ul><ul><li>Selective photo crosslinking of biomaterials </li></ul></ul><ul><ul><li>Rapid Prototyping of rigid master for transfer purposes </li></ul></ul><ul><li>Design Goal: Develop repeatable micro-particle fabrication process for use with multiple materials and shapes </li></ul>
  4. 4. Rapid Prototyping <ul><li>Microparticles designed as two dimensional architectures extruded in the third dimension </li></ul><ul><ul><li>Cube, y-shape and asterisk </li></ul></ul><ul><li>Architectures generated at identical volume of sodium chloride (NaCl) porogen </li></ul><ul><li>Surface area of each particle ranged based upon the geometry </li></ul><ul><li>Particles built using Patternmaster </li></ul>
  5. 5. Soft Lithography * Poly(dimethylsiloxane) # Poly(propylene fumarate) di-ethyl fumarate Glass PDMS Mold PPF-DEF # Place in Vacuum Metal Clamp Remove PDMS Microparticles Microparticle Platform Degassed PDMS Microparticle Platform Let cure 24 Hours, peel away PDMS 2) Pour PDMS platform <ul><ul><li>Degass PDMS* </li></ul></ul>Silicon Master Negative
  6. 6. Printing Considerations <ul><li>Best plotter path selected for optimum shape replication </li></ul><ul><li>Extruded rim minimized curling of microparticle platforms </li></ul>
  7. 7. Photolithographic Transfer <ul><li>Successive geometric complexity increased part error and reduced clarity of geometry </li></ul><ul><li>Silicon molds display complete transfer of the global shape </li></ul>
  8. 8. Morphological Analysis <ul><li>Dimensional measurement of steps leading to production of final microparticles </li></ul><ul><li>All architectures smaller than designed </li></ul><ul><li>Similar material shrinkage measured for all architectures </li></ul><ul><ul><li>Compensation mechanism could account for modification </li></ul></ul>
  9. 9. Conclusions <ul><li>Microparticles built repeatably with conservation of architecture </li></ul><ul><ul><li>Average of 98.6% reclamation for architectures </li></ul></ul><ul><ul><li>Average 56.3% deviation from designed architecture </li></ul></ul><ul><ul><li>Decreased shape matching with increased complexity </li></ul></ul><ul><li>Process is material independent allowing versatility based upon design considerations </li></ul><ul><li>Compensation algorithm could surpass resolution restrictions </li></ul><ul><li>Same associated benefits and difficulties as each separate method </li></ul><ul><ul><li>Mold filling, sterilization, mold distortion </li></ul></ul><ul><ul><li>Size constraint imposed by use of rapid prototyping </li></ul></ul><ul><li>Considerable cost reduction and versatility with any current methodologies employing silicone templates </li></ul>
  10. 10. Future Directions <ul><li>Future Directions </li></ul><ul><ul><li>Development of compensation algorithm to allow for creation of specific features </li></ul></ul><ul><ul><li>Geometric analysis of microparticle transfer methodology </li></ul></ul><ul><ul><li>Morphological analysis of porous solids created with microparticles </li></ul></ul><ul><ul><li>Permeability and mechanical testing of porous solids </li></ul></ul>
  11. 11. Acknowledgements <ul><li>Molly Mullican and Chris Chen for microparticle work </li></ul><ul><li>Chris Chen for rapid prototyping image work </li></ul><ul><li>NSF-ITR as funding source </li></ul>

×