SYSTEMS AND METHODS FOR FILTERING NANOWIRES
In order to filter a solution containing nanowires, a flow of the solution is generated and directed through a passage defining an aperture having a narrow width. Alternatively, a flow of the solution may be generated and directed over a micro-structured surface configured to filter the solution.
1 . A method, comprising:
providing a solution containing nanowires and a first set of contaminant particles;
generating a flow of the solution; and
filtering the solution by directing the flow through a passage defining an aperture having a width less than at least one dimension of the first set of contaminant particles.
2 . The method of claim 1 , wherein the passage is formed at least in part by two substantially parallel plates separated by less than the at least one dimension of the first set of contaminant particles.
3 . The method of claim 2 , wherein at least one of the plates includes an opening therethrough, through which the flow is directed.
4 . The method of claim 3 , wherein the solution flows radially outward between the pair of plates from the opening.
5 . The method of claim 1 , further comprising:
stopping the flow of the solution;
generating a reverse flow of a liquid; and
directing the reverse flow through the passage in a direction opposite to the flow of the solution.
6 . The method of claim 5 , wherein the reverse flow is generated in response to a reduction in a flow rate of the flow of the solution through the passage.
7 . The method of claim 5 , wherein the reverse flow is generated periodically.
8 . The method of claim 1 , wherein the solution further contains a second set of contaminant particles, the second set of contaminant particles having at least one dimension smaller than the at least one dimension of the first set of contaminant particles, the method further comprising:
directing the flow through a second passage defining a second aperture having a width less than the at least one dimension of the second set of contaminant particles.
9 . The method of claim 8 , wherein the solution further contains a third set of contaminant particles, the third set of contaminant particles having at least one dimension smaller than the at least one dimension of the second set of contaminant particles, the method further comprising:
directing the flow through a third passage defining a third aperture having a width less than the at least one dimension of the third set of contaminant particles.
10 . The method of claim 9 , wherein the flow is directed through the passage, then the second passage, and then the third passage.
11 . The method of claim 1 , wherein the passage is formed at least in part by two converging plates, and wherein the passage narrows from an entrance of the passage to an exit of the passage.
12 . The method of claim 11 , wherein the aperture comprises the exit of the passage.
13 . The method of claim 1 , further comprising:
generating a reverse flow of the solution; and
directing the reverse flow through the passage in a direction opposite to the flow of the solution;
wherein a flow rate of the flow and a flow rate of the reverse flow are chosen such that there is a net flow of the solution towards an exit of the passage.
14 . A nanowire filtering system comprising:
a source container for holding a solution containing nanowires and a first set of contaminant particles; and
a nanowire filter passage communicatively coupled to the source container for receiving the solution, the nanowire filter passage defined at least in part by:
a first plate; and
a second plate disposed adjacent the first plate with a minimum separation distance between the first plate and the second plate of less than at least one dimension of the first set of contaminant particles.
15 . The nanowire filtering system of claim 14 , wherein the first plate defines an opening therethrough, the opening disposed opposite the second plate.
16 . The nanowire filtering system of claim 15 , wherein the opening is substantially circular.
17 . The nanowire filtering system of claim 14 , wherein the first plate and the second plate are substantially parallel.
18 . The nanowire filtering system of claim 14 , wherein the solution further contains a second set of contaminant particles, the second set of contaminant particles having at least one dimension smaller than the at least one dimension of the first set of contaminant particles, the nanowire filtering system further comprising:
a second nanowire filter passage communicatively coupled to the nanowire filter passage, the second nanowire filter passage defined at least in part by:
a third plate; and
a fourth plate disposed adjacent the third plate with a minimum separation distance between the third plate and the fourth plate of less than the at least one dimension of the second set of contaminant particles.
19 . The nanowire filtering system of claim 18 , wherein the solution further contains a third set of contaminant particles, the third set of contaminant particles having at least one dimension smaller than the at least one dimension of the second set of contaminant particles, the nanowire filtering system further comprising:
a third nanowire filter passage communicatively coupled to the second nanowire filter passage, the third nanowire filter passage defined at least in part by:
a fifth plate; and
a sixth plate disposed adjacent the fifth plate with a minimum separation distance between the fifth plate and the sixth plate of less than the at least one dimension of the third set of contaminant particles.
20 . The nanowire filtering system of claim 14 , wherein the first plate and the second plate converge, and wherein the nanowire filter passage narrows.
21 . The nanowire filtering system of claim 14 , further comprising a pump for generating a flow of the solution from the source container through the nanowire filter passage.
22 . A method, comprising:
providing a solution containing nanowires;
generating a primary flow of the solution; and
filtering the solution by directing the primary flow over a micro-structured surface configured to filter the solution.
23 . The method of claim 22 , wherein the micro-structured surface includes a plurality of openings through the surface.
24 . The method of claim 22 , wherein the plurality of openings have an average diameter of greater than 5 μm.
25 . A nanowire filtering system comprising:
a source container for holding a solution containing nanowires; and
a nanowire filter communicatively coupled to the source container for receiving the solution, the nanowire filter including:
a rotatable tube defining a passage for the solution;
a micro-structured surface lining an inside of the rotatable tube;
a substantially helical element adjacent the micro-structured surface and extending at least partially into the passage; and
a drive member adapted to turn the rotatable tube.
26 . A nanowire filtering system comprising:
a source container for holding a solution containing nanowires; and
a nanowire filter communicatively coupled to the source container for receiving the solution, the nanowire filter including:
an elongate channel defining a passage for the solution flowing along a long axis, the elongate channel having a lower surface including a plurality of parallel ridges disposed at an angle to the long axis;
wherein the plurality of parallel ridges at least partially define a plurality of openings from the elongate channel.
27 . A nanowire filtering system comprising:
a source container for holding a solution containing nanowires; and
a nanowire filter communicatively coupled to the source container for receiving the solution, the nanowire filter including:
an elongate channel defining a passage for the solution; and
a collection chamber defined in part by an outer surface of the elongate channel, the collection chamber communicatively coupled to the elongate channel via a plurality of openings having an average diameter of greater than 5 μm.