1. An apparatus for reducing backflow, the apparatus comprising:
a plurality of supply inlets adapted to be connected to at least one corresponding supply source for a liquid;
a plurality of supply lines connecting the plurality of supply inlets to a point of use outlet, each supply line comprising a first valve, a first vessel, and a second valve in that order from a corresponding supply inlet to the point of use outlet;
a sweep gas inlet adapted to be connected to a sweep gas source, the sweep gas being inert relative to the liquid;
a vent line connecting the sweep gas inlet to a vent outlet, the sweep gas flowing from the sweep gas inlet to the vent outlet via the vent line, each supply line of the plurality of supply lines connected to the vent line through a separate corresponding one of a plurality of vent valves;
a plurality of branch lines connecting each first vessel of each supply line to the vent line, each branch line comprising a first end;
a junction connecting the first end of each branch line to the vent line; and
a control system that:
in a liquid supply state, opens one of the first valves and opens a corresponding one of the second valves and closes the vent valve corresponding to the open first valve and the open second valve, the liquid flowing from the corresponding supply inlet to the point of use outlet via the corresponding open first valve, the corresponding first vessel, and then the corresponding open second valve, in that order,
in a stop state, closes the previously opened first valve and closes the previously opened second valve corresponding to the previously opened first valve and opens the corresponding vent valve, such that the flow of sweep gas from the corresponding sweep gas inlet to the vent outlet sweeps out liquid in the first vessel corresponding to the closed first valve and second valve via the corresponding branch line to the vent outlet,
the control system preventing backflow in the supply lines by opening the corresponding vent valve.
2. The apparatus of claim 1, wherein the sweep gas comprises a process-inert gas that does not contaminate the liquid for purposes of a process served by the liquid.
3. The apparatus of claim 2, wherein the process-inert gas comprises one of the following: air, purified nitrogen, or argon-helium mixture gas; and wherein the liquid comprises one of the following: chemical mechanical polishing slurry or deionized water.
4. The apparatus of claim 1, wherein the control system comprises a logic component for generating a control signal to open or close the vent valve, the logic component comprising a pneumatic circuit or an electronic circuit.
5. An apparatus for reducing backflow and detecting leaks in an interconnected pressurized liquid delivery system, the apparatus comprises:
a first supply inlet adapted to be connected to a first supply source for a first liquid;
a first supply line connecting the first supply inlet to a point of use outlet, the first supply line comprising a first valve, a first vessel, and a second valve in that order from the first supply inlet to the point of use outlet;
a second supply inlet adapted to be connected to a second supply source for a second liquid;
a second supply line connecting the second supply inlet to the point of use outlet, the second supply line comprising a third valve, a second vessel, and a fourth valve in that order from the second supply inlet to the point of use outlet;
a sweep gas inlet adapted to be connected to a sweep gas source, the sweep gas being inert relative to the first liquid and the second liquid and relative to processes served by the liquids;
a vent line connecting the sweep gas inlet to a vent outlet, the sweep gas flowing at a constant flow rate from the sweep gas inlet to the vent outlet via the vent line;
a first vent valve connecting the vent line with the first vessel;
a second vent valve connecting the vent line with the second vessel;
a flow switch disposed on the vent line between said two vent valves and the vent outlet for sensing fluid that flows through the vent line into the vent outlet, the flow switch configured to actuate responding to fluid passing through the vent line into the vent outlet exceeding the constant flow rate, wherein the fluid comprises the sweep gas and any leaked liquid; and
a control system that:
in a first liquid supply state, opens the first valve, the second valve, and the second vent valve, and closes the third valve, the fourth valve, and the first vent valve, the liquid flowing from the first supply inlet to the point of use outlet via the first valve, the first vessel, and the second valve, in that order
in a second liquid supply state, opens the third valve, the fourth valve, and the first vent valve, and closes the first valve, the second valve, and the second vent valve, the liquid flowing from the second supply inlet to the point of use outlet via the third valve, the second vessel, and the fourth valve, in that order, and
in a stop state, closes the first valve, the second valve, the third valve, the fourth valve, and opens the first vent valve and the second vent valve such that the flow of sweep gas from the sweep gas inlet to the vent outlet sweeps out liquid in the first vessel and in the second vessel via the vent outlet.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An array of features comprising at least 10,000 features, each feature is attached to a surface of the array at a different positionally-defined location, the positionally-defined location of each feature corresponds to a positionally-defined location of a pillar, wherein the top surface of each pillar is at least 1 \u03bcm2 in size, and
wherein each feature comprises a different predetermined peptide chain compared to the other features, each feature comprises at least 500 identical full-length peptide chains, wherein each identical full-length peptide chain has a predetermined full-length of at least 7 amino acids in length, and
the purity of each feature with regards to the fraction of full-length predetermined peptide chains is a fraction F of the full-length predetermined peptide chains of each feature having a predetermined sequence and a predetermined full-length sequence length N being characterized by F=10(N+1)\xb7log(E100%) with an average coupling efficiency E of at least 98.5% for coupling each amino acid of the predetermined sequence, and the sequence length N being at least 7 amino acids in length, the fraction of the less than full-length predetermined peptide chains equaling (1-F); and
the surface comprising a substrate, the substrate comprising:
a planar layer having an upper surface and a lower surface, and
a plurality of pillars operatively coupled to the layer in the positionally-defined locations, wherein each pillar has a planar surface extended from the layer, wherein the distance between the surface of each pillar and the upper surface of the layer is between 1,000-5,000 angstroms, and wherein the plurality of pillars are present at a density of greater than 10,000cm2.
2. The array of claim 1, wherein said surface comprises a porous surface layer, and
said porous layer comprises a plurality of free carboxylic acid groups.
3. The array of claim 2, wherein said carboxylic acid groups are oriented in multiple directions.
4. The array of claim 2, wherein said porous layer comprises a plurality of coupling molecules each attached to said array via a carboxylic acid group.
5. The array of claim 2, wherein said porous layer comprises a plurality of peptide chains each attached to said array via a carboxylic acid group.
6. The array of claim 1, wherein the features comprise a plurality of distinct, nested, overlapping peptide chains comprising subsequences derived from a source protein having a known sequence.
7. The array of claim 1, wherein the surface comprises a substrate, the substrate comprising: a first layer, wherein said first layer comprises a plurality of unprotected carboxylic acid side groups.
8. The array of claim 1, wherein the planar layer comprises a metal.
9. A method of producing an array of features, comprising:
obtaining a substrate comprising a planar layer having an upper surface and a lower surface; and a plurality of pillars operatively coupled to the layer in different positionally-defined locations, wherein each pillar has a planar surface extended from the layer, wherein the distance between the surface of each pillar and the upper surface of the layer is between 1,000-5,000 angstroms, wherein the surface of each pillar is parallel to the upper surface of the layer, and wherein the plurality of pillars are present at a density of greater than 10,000cm2; and
coupling through a series of coupling reactions the features to the plurality of pillars, each features attached at different positionally-defined locations comprising a plurality of peptide chains, the positionally-defined location of each feature corresponds to a positionally-defined location of a pillar, wherein the top surface of each pillar is at least 1 \u03bcm2 in size, and
wherein each feature comprises a different predetermined peptide chain compared to the other features, each feature comprises at least 500 identical full-length peptide chains, wherein each identical full-length peptide chain has a predetermined full-length of at least 7 amino acids in length, and the purity of each feature with regards to the fraction of full-length predetermined peptide chains is a fraction F of the full-length predetermined peptide chains of each feature having a predetermined sequence and a predetermined full-length sequence length N being characterized by F=10(N+1)\xb7log(E100%) with an average coupling efficiency E of at least 98.5% for coupling each amino acid of the predetermined sequence, and the sequence length N being at least 7 amino acids in length, the fraction of the less than full-length predetermined peptide chains equaling (1-F); and wherein the array comprises at least unique 10,000 features.
10. The method of claim 9, wherein the features are coupled to the pillars using a coupling formulation, comprising a solvent, a water soluble polymer, a water soluble coupling molecule, a water soluble neutralization reagent, and a water soluble coupling reagent.