Method of manufacturing microneedle structures using soft lithography and photolithography

A method for fabricating microneedles, said method comprising:

• (a) providing a substrate that includes a plurality of microstructures;
• (b) coating said substrate with a layer of a first moldable material that takes the negative form of said plurality of microstructures, and hardening said first moldable material;
• (c) separating said hardened first moldable material from said substrate, thereby creating a micromold from said hardened first moldable material containing said plurality of microstructures;
• (d) applying a second moldable material onto said micromold, allowing said second moldable material to harden using a soft lithography procedure, then separating said hardened second moldable material from said micromold, thereby creating a microneedle structure from said hardened second moldable material having the three-dimensional negative form of said plurality of microstructures of the patterned micromold;
• (e) providing a second substrate that includes a second plurality of microstructures, wherein said second plurality of microstructures is substantially complementary in shape as compared to said first plurality of microstructures;
• (f) coating said second substrate with a layer of a third moldable material that takes the negative form of said second plurality of microstructures, and hardening said third moldable material;
• (g) separating said hardened third moldable material from said second substrate, thereby creating a second micromold from said hardened third moldable material containing said second plurality of microstructures;
• (h) applying a fourth moldable material onto said second micromold, allowing said fourth moldable material to harden using a soft lithography procedure, then separating said hardened fourth moldable material from said second micromold, thereby creating a second microneedle structure from said hardened fourth moldable material having the three-dimensional negative form of said second plurality of microstructures of the patterned second micromold;
• and
• (i) applying a layer of a fifth moldable material upon one of said first or second microneedle structures, placing said first and second microneedle structure into a face-to-face relationship to thereby sandwich said layer of fifth moldable material therebetween, allowing said layer of fifth moldable material to harden using a soft lithography procedure, then separating said hardened fifth moldable material from both said first and second microneedle structures, thereby creating a third microneedle structure from said hardened fifth moldable material having the three-dimensional negative form of both said first and second microneedle structures.

A method for fabricating microneedles, said method comprising:

• (a) providing a substrate that includes a plurality of microstructures;
• (b) coating said substrate with a layer of a first moldable material that takes the negative form of said plurality of microstructures, and hardening said first moldable material;
• (c) separating said hardened first moldable material from said substrate, thereby creating a micromold from said hardened first moldable material containing said plurality of microstructures;
• and
• (d) applying a second moldable material onto said micromold, allowing said second moldable material to harden using a soft lithography procedure, then separating said hardened second moldable material from said micromold, thereby creating a microneedle structure from said hardened second moldable material having the three-dimensional negative form of said plurality of microstructures of the patterned micromold;
• wherein said first moldable material after hardening exhibits a flexibility characteristic and, therefore, can be deformed to a predetermined extent without breaking;
• and further comprising:
• after creating said micromold from said hardened, flexible first moldable material, deforming said micromold during the step of applying the second moldable material onto said micromold, thereby creating either a concave or convex micromold.