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Systems and methods for mixing reactantsRelated Patent Categories: Single-crystal, Oriented-crystal, And Epitaxy Growth Processes; Non-coating Apparatus Therefor, Processes Of Growth From Liquid Or Supercritical State, Having Pulling During Growth (e.g., Czochralski Method, Zone Drawing), With A Step Of Measuring, Testing, Or Sensing (e.g., Using Tv, Photo, Or X-ray Detector Or Weight Changes)Systems and methods for mixing reactants description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070169686, Systems and methods for mixing reactants. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This nonprovisional patent application is a continuation-in-part of nonprovisional patent application Ser. No. 09/826,585 filed Apr. 6, 2001. The text of this prior patent application is hereby incorporated by reference. BACKGROUND OF THE INVENTION [0003] Crystallization is an important technique to the biological and chemical arts. Specifically, a high-quality crystal of a target compound can be analyzed by x-ray diffraction techniques to produce an accurate three-dimensional structure of the target. This three-dimensional structure information can then be utilized to predict functionality and behavior of the target. [0004] In theory, the crystallization process is simple. A target compound in pure form is dissolved in solvent. The chemical environment of the dissolved target material is then altered such that the target is less soluble and reverts to the solid phase in crystalline form. This change in chemical environment typically accomplished by introducing a crystallizing agent that makes the target material is less soluble, although changes in temperature and pressure can also influence solubility of the target material. [0005] In practice however, forming a high quality crystal is generally difficult and sometimes impossible, requiring much trial and error and patience on the part of the researcher. Specifically, the highly complex structure of even simple biological compounds means that they are not amenable to forming a highly ordered crystalline structure. Therefore, a researcher must be patient and methodical, experimenting with a large number of conditions for crystallization, altering parameters such as sample concentration, solvent type, countersolvent type, temperature, and duration in order to obtain a high quality crystal, if in fact a crystal can be obtained at all. [0006] Accordingly, there is a need in the art for methods and structures for performing high throughput screening of crystallization of target materials. SUMMARY OF THE INVENTION [0007] The present invention sets forth method and structures for performing high throughput screening of crystallization of target materials. Methods and structures for purifying small samples by recrystallization are also provided. [0008] High throughput screening of crystallization of a target material is accomplished by simultaneously introducing a solution of the target material at a known concentration into a plurality of chambers of a microfabricated fluidic device. The microfabricated fluidic device is then manipulated to vary the solvent concentration in each of the chambers, thereby simultaneously providing a large number of crystallization environments. Control over changed solvent conditions may result from a variety of techniques, including but not limited to metering of a crystallizing agent through exclusion of volume from the chamber, entrapment of precisely controlled volumes of crystallizing agent as determined by the dimensions of the microfluidic device, or cross-channel injection into an array of junctions defined by intersecting orthogonal flow channels. [0009] An embodiment of a method of metering a volume of a crystallizing agent to promote crystallization in accordance with the present invention comprises providing a chamber having a volume in an elastomeric block separated from a control recess by an elastomeric membrane, and supplying a pressure to the control recess such that the membrane is deflected into the chamber and the volume is reduced by a calibrated amount, thereby excluding from the chamber a calibrated volume of a crystallization sample. This method may further comprise providing a second fluid to an opening of the chamber, and ceasing application of the pressure such that the membrane relaxes back to an original position and the calibrated volume of a crystallizing agent is drawn into the chamber. This method may also further comprise the parallelization of multiple chambers with varying calibrated volumes. [0010] An embodiment of a system for crystallizing a target material in accordance with the present invention comprises an elastomeric block including a microfabricated chamber configured to contain a volume of a solution of the target material, and a microfabricated flow channel in fluid communication with the chamber, the flow channel introducing a volume of a crystallizing agent into the chamber. The crystallization system may further comprise an isolation structure configured to selectively isolate the chamber from the flow channel as the flow channel receives a volume of a crystallizing agent, and then to place the chamber into contact with the flow channel to alter a solution condition within the chamber. Alternatively, the crystallization system may further comprise a control channel overlying the chamber and separated from the chamber by a membrane, the membrane deflectable into the chamber to exclude a calibrated volume of sample solution from the chamber, such that relaxation of the membrane draws the calibrated volume of the crystallizing agent into the chamber. Further alternatively, the crystallization system may comprise a plurality of first parallel flow channels in fluid communication with a target material, and a plurality of second parallel flow channels orthogonal to and intersecting the first flow channels to create a plurality of junctions, the second flow channels in fluid communication with a crystallizing agent such that an array of solution environments can be created at the junctions. [0011] Another embodiment of a system for crystallizing a target material in accordance with the present invention comprises an elastomeric block including a microfabricated chamber configured to contain a volume of a solution of the target material, and a crystallizing agent reservoir in fluid communication with the microfabricated chamber through a dialysis membrane, the dialysis membrane configured to prevent flow of the target material into the crystallizing agent reservoir. The crystallizing agent reservoir may be formed in a second elastomeric block, the dialysis membrane may be present within the elastomeric block, and the dialysis membrane may comprise a polymer introduced between the chamber and the reservoir and then subjected to cross-linking. [0012] An embodiment of a method for crystallizing a target material in accordance with the present invention comprises charging a chamber of a microfabricated elastomeric block with a volume of solution of the target material; and introducing a volume of a crystallizing agent into the chamber to change a solvent environment of the chamber. The volume of crystallizing agent may be introduced into the chamber by deforming an elastomer membrane overlying the chamber to exclude the volume of the sample from the chamber, followed by relaxing the membrane to cause the volume of a surrounding crystallizing agent to flow into the chamber. Alternatively, the volume of crystallizing agent may be introduced into the chamber by entrapping a volume of crystallizing agent proximate to the chamber, and then opening an elastomer valve positioned between the chamber and the crystallizing agent to allow diffusion of crystallizing agent into the chamber. Further alternatively, the volume of crystallizing agent may be introduced into the chamber by diffusion across a dialysis membrane. [0013] Still further alternatively, the chamber may be defined by a junction between a first flow channel orthogonal to a second flow channel, and wherein the sample is flowed through the first flow channel and the crystallizing agent flowed through the second flow channel. An array of such chambers may be defined by a junction between a first set of parallel flow channels orthogonal to a second set of parallel flow channels, with samples flowed through the first flow channels and crystallizing agent flowed through the second flow channels to create an array of solution conditions. [0014] An embodiment of a method for crystallizing a target material comprises introducing a crystallizing agent to a target material solution in the presence of a surface having a morphology calculated to serve as a template for formation of a crystal of the target material. In certain embodiments, this morphology may take the form of a regular morphology of a mineral surface, or features of a semiconductor substrate patterned by lithography. [0015] An embodiment of a method for crystallizing a target material by vapor diffusion in accordance with the present invention comprises providing a target material solution within a microfabricated chamber, and providing a recrystallizing agent in fluid communication with the microfabricated chamber. An air pocket is provided between the chamber and the recrystallization agent, such that the crystallizing agent diffuses in the vapor phase across the air pocket into the target material solution. In certain embodiments, the air pocket may be secured in place through formation of a hydrophobic material utilizing microcontact printing techniques. [0016] These and other embodiments of the present invention, as well as its advantages and features, are described in more detail in conjunction with the text below and attached figures. BRIEF DESCRIPTION OF THE DRAWINGS [0017] FIG. 1 is an illustration of a first elastomeric layer formed on top of a micromachined mold. [0018] FIG. 2 is an illustration of a second elastomeric layer formed on top of a micromachined mold. [0019] FIG. 3 is an illustration (of the elastomeric layer of FIG. 2 removed from the micromachined mold and positioned over the top of the elastomeric layer of FIG. 1 [0020] FIG. 4 is an illustration corresponding to FIG. 3, but showing the second elastomeric layer positioned on top of the first elastomeric layer. [0021] FIG. 5 is an illustration corresponding to FIG. 4, but showing the first and second elastomeric layers bonded together. Continue reading about Systems and methods for mixing reactants... Full patent description for Systems and methods for mixing reactants Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Systems and methods for mixing reactants patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Systems and methods for mixing reactants or other areas of interest. ### Previous Patent Application: Nitrogen-doped silicon substantially free of oxidation induced stacking faults Next Patent Application: Silicon carbide formation by alternating pulses Industry Class: Single-crystal, oriented-crystal, and epitaxy growth processes; non-coating apparatus therefor ### FreshPatents.com Support Thank you for viewing the Systems and methods for mixing reactants patent info. IP-related news and info Results in 0.20795 seconds Other interesting Feshpatents.com categories: Medical: Surgery , Surgery(2) , Surgery(3) , Drug , Drug(2) , Prosthesis , Dentistry 174 |
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