1. 1 A NOVEL FRAMEWORK OF MAKING PLA/PLGA POLYMER MICRO NEEDLES PATCH FOR BETTER SKIN PIERCING AND DRUG RELEASE LIGA and Biophotonics Lab NTHU Institute of NanoEngineering and MicroSystem Speaker ： Wen Cheng Yang

2. 2 Outline Introduction Fabricated polymer micro needles array PLA/PLGA soft micro needles Flexible membrane substrate Conclusion LIGA and Biophotonics Lab

3. 3 Introduction Fabricated polymer micro needles array PLA/PLGA soft micro needles Flexible membrane substrate Conclusion Outline LIGA and Biophotonics Lab

4. 4 Introduction Many reports have been published to fabricate micro needles over the past ten years. One of the most important potential applications is the patch with micro needles array on it for efficient drug delivery purpose. LIGA and Biophotonics Lab

5. 5 Introduction Fabrication micro needles ： 1. solid micro needles array 2. hollow needle array 3. polymer needles patch on flexible membrane

6. 6 Introduction Fabricated polymer micro needles array PLA/PLGA soft micro needles Flexible membrane substrate Conclusion Outline LIGA and Biophotonics Lab

7. 7 Fabricated polymer micro needles array Fabricated polymer micro needles array by the purposed back-side exposure method. Out-of-plane polymer micro needles with a height of 65 ~ 210 um and an outer diameter between 20 ~ 100 um have been successfully realized. LIGA and Biophotonics Lab

8. 8 Fabricated polymer micro needles array An example result made by the combinational method. The outside wall had a larger tilting angle, while the internal wall had a smaller tilting angle (nearly vertical) can be made by one lithography step. LIGA and Biophotonics Lab

9. 9 Fabricated polymer micro needles array Different kinds of hollow polymer micro needles can be fabricated through the purposed method. LIGA and Biophotonics Lab

10. 10 Introduction Fabricated polymer micro needles array PLA/PLGA soft micro needles Flexible membrane substrate Conclusion Outline LIGA and Biophotonics Lab

11. 11 Poly lactic acid （ PLA, 聚乳酸） Poly lactide-co-glycolide （ PLGA, 聚甘醇酸共聚物） PLA/PLGA soft micro needles LIGA and Biophotonics Lab

12. 12 PLA/PLGA soft micro needles PDMS i ntermediate PLA powder spread over the PDMS mold PLGA + Albumin LIGA and Biophotonics Lab

13. 13 Introduction Fabricated polymer micro needles array PLA/PLGA soft micro needles Flexible membrane substrate Conclusion Outline LIGA and Biophotonics Lab

14. 14 Flexible membrane substrate The needles array fabricated on a flexible membrane substrate. The substrate employed here was PDMS. LIGA and Biophotonics Lab

15. 15 Flexible membrane substrate PLA micro needles array ( 900 needles in 0.5×0.5 mm 2 area) fabricated by replication through a PDMS intermediate mold LIGA and Biophotonics Lab

16. 16 Flexible membrane substrate (a) (b) (c) (d) Optical micrographs showing piercing experiments. (a)The human skin of hand back of an Asian people before piercing. (b)After piercing by a fabricated PLA needles array. (c)Test result using artificial skin: Cica-Caretm from Smith+Nephew Corp (d) Test result using simulated agarose gel with the standard hardness range of human skin. LIGA and Biophotonics Lab

17. 17 Introduction Fabricated polymer micro needles array PLA/PLGA soft micro needles Flexible membrane substrate Conclusion Outline LIGA and Biophotonics Lab

18. 18 In this paper, we introduced our fabrication approach, preparation methods and the produced patches. We have also executed piercing experiments on artificial skin and real human skin. LIGA and Biophotonics Lab Conclusion

19. 19 LIGA and Biophotonics Lab Thanks for your attendance.