Microfluidic control surfaces using ordered nanotube fabrics
A method for arranging nanotube elements within nanotube fabric layers and films is disclosed. A directional force is applied over a nanotube fabric layer to render the fabric layer into an ordered network of nanotube elements. That is, a network of nanotube elements drawn together along their sidewalls and substantially oriented in a uniform direction. In some embodiments this directional force is applied by rolling a cylindrical element over the fabric layer. In other embodiments this directional force is applied by passing a rubbing material over the surface of a nanotube fabric layer. In other embodiments this directional force is applied by running a polishing material over the nanotube fabric layer for a predetermined time. Exemplary rolling, rubbing, and polishing apparatuses are also disclosed.
1. A nanotube fabric for microfluidics, comprising:
a nanotube fabric comprising a plurality of nanotube elements;
wherein said nanotube fabric comprises at least one region of substantially un-ordered nanotubes and at least one region of substantially ordered nanotubes;
wherein said at least one region of substantially ordered nanotubes is rendered into said ordered state according to a selected pattern;
wherein said selected pattern of ordered nanotubes are oriented in a selected direction corresponding to a desired path for a liquid to flow and said selected pattern defines at least one path for a liquid to flow along said selected direction.
2. The nanotube fabric of claim 1 wherein the width of said at least one path is on the order of 50-100 μm.
3. The nanotube fabric of claim 1 wherein the width of said at least one path is on the order of 10-50 μm.
4. The nanotube fabric of claim 1 wherein the width of said at least one path is on the order of 1-10 μm.
5. The nanotube fabric of claim 1 wherein the width of said at least one path is on the order of 0.1-1 μm.
6. The nanotube fabric of claim 1 wherein said nanotube fabric additionally comprises at least one additive, said additive including surfactants, binders, nanoscopic particles, polymers, dopants, organic molecules and inorganic molecules.
7. The nanotube fabric of claim 6 wherein at least one of said additives is chemically reactive.
8. The nanotube fabric of claim 6 wherein at least one of said additives is photosensitive.
9. The nanotube fabric of claim 6 wherein at least one of said at least one additives is applied to a selected region of said nanotube fabric.
10. The nanotube fabric of claim 1 wherein the hydrophobicity of said at least one region of substantially ordered nanotubes is selected to provide a particular flow rate for a selected liquid.
11. The nanotube fabric of claim 1 wherein said selected pattern comprises at least one microfluidic component, including a micro-reactor, channel, sensor, size-exclusion channel, and tortuous path.
12. The nanotube fabric of claim 11 wherein said selected pattern is the outline of said microfluidic component.
13. The nanotube fabric of claim 1 wherein the pattern of said at least one region of substantially ordered nanotubes is capable of being altered.
14. The nanotube fabric of claim 13 wherein said alteration changes the direction of at least one of said at least one path.
15. The nanotube fabric of claim 13 wherein said alteration produces a new path for liquid to flow.