Nanostructures from laser-ablated nanohole templates
Solution casting a nanostructure. Preparing a template by ablating nanoholes in a substrate using single-femtosecond laser machining. Replicating the nanoholes by applying a solution of a polymer and a solvent into the template. After the solvent has substantially dissipated, removing the replica from the substrate.
1. A method for fabricating a nanofiber array, comprising:
providing a template comprising a transparent substrate having a surface, the surface comprising a plurality of nanoholes, each nanohole of the plurality being ablated in the surface using a laser;
applying a flowable polymer into the plurality of nanoholes; and
extracting an array of polymer nanofibers from the template;
wherein the nanofibers have an aspect ratio of at least ten-to-one and a diameter of less than 1000 nanometers.
2. The method of claim 1 , wherein the flowable polymer includes a polymer capable of forming a continuous film.
3. The method of claim 1 , wherein the flowable polymer does not contain a solvent.
4. The method of claim 1 , wherein the flowable polymer is a polymer resin.
5. The method of claim 1 , wherein the flowable polymer overflows the plurality of nanoholes and covers at least a portion of the surface of the template such that the flowable polymer connects at least some of the plurality of nanoholes.
6. The method of claim 1 , wherein said extracting is lifting or peeling the array of polymer nanofibers away from the surface of the template.
7. The method of claim 1 , wherein the nanofibers are not hollow or porous.
8. The method of claim 1 , wherein the array comprises a plurality of freestanding polymer nanofibers extending from a surface of a polymer substrate.
9. The method of claim 8 , wherein the polymer nanofibers are positioned on the polymer substrate in a non-random, user-defined pattern.
10. The method of claim 1 , further comprising treating the surface of the template with a material to modify the surface and bonding characteristics associated with the template and the array.
11. The method of claim 1 , further comprising applying a fluorocarbon-based antistick coating to the template prior to applying the flowable polymer into the plurality of nanoholes.
12. A method for fabricating a nanofiber array, comprising:
providing a template comprising a transparent substrate having a surface, the surface comprising a plurality of nanoholes, each nanohole of the plurality being ablated in the surface using a laser;
filling the plurality of nanoholes with a polymer resin; and
lifting or peeling an array of polymer nanofibers away from the surface of the template;
wherein the nanofibers have an aspect ratio of at least ten-to-one and a diameter of less than 1000 nanometers.
13. The method of claim 12 , wherein the nanofibers have an average length greater than ten micrometers.
14. The method of claim 12 , wherein the nanofibers have an aspect ratio of greater than twenty-five-to-one.
15. The method of claim 12 , wherein the nanofibers have an average length greater than 25 micrometers.
16. A method for fabricating an array of nanofibers, comprising:
providing a template having a surface comprising a plurality of nanoholes, each nanohole of the plurality being ablated in the surface using a laser;
applying a flowable polymer capable of forming a continuous film into the nanoholes until the flowable polymer covers at least a portion of the surface of the template and connects at least some of the plurality of nanoholes;
allowing the flowable polymer to form the continuous film on the portion of the surface of the template; and
removing the continuous film from the surface of the template;
wherein the continuous film comprises an array of nanofibers having an aspect ratio of at least ten-to-one and a diameter of less than 1000 nanometers.