Systems and methods for evaporating solvents from samples

Abstract

An evaporator is provided. The evaporator can comprise a channel system, a sample holder, a compressor, and a condenser. The channel system can comprise one or more channels. The sample holder can comprise a first chamber in fluid communication with the channel system and configured to hold a first sample comprising a first solvent. The compressor can be in fluid communication with the channel system and configured to cause a fluid to flow through the first chamber to cause at least a portion of the solvent in the sample to evaporate to form an at least partially saturated fluid. The condenser can be in fluid communication with the channel system and configured to receive the at least partially saturated fluid and remove, via condensation, at least a portion of the solvent in the at least partially saturated fluid to generate a dry fluid.

Description

SYSTEMS AND METHODS FOR EVAPORATING SOLVENTS FROM SAMPLESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 669,114 filed on 9 July 2024, which is incorporated herein by reference in its entirety as if fully set forth below.GOVERNMENT LICENSE RIGHTS

[0002] This invention was made with government support under Agreement No. R25GM142044, awarded by the National Science Foundation. The government has certain rights in the invention.FIELD OF THE DISCLOSURE

[0003] The various embodiments of the present disclosure relate generally to evaporation systems and methods, and more particularly, to portable, low-cost, and energy efficient systems and methods for rapidly extracting solvents from samples.BACKGROUND

[0004] Solvent removal from solutions is commonly performed in laboratory and production processes. There are a number of different methods that can be used for solvent removal, including evaporation, vacuum concentration, lyophilization, reverse extraction, solute precipitation, and dialysis (solvent exchange).

[0005] Solutes that are not volatile can be concentrated by drawing the solvent into a gaseous headspace. Two approaches can be used for solvent removal, one being by boiling and the other by directing a stream of (inert) gas over the solvent. In this latter approach, the gas essentially extracts solvent from the liquid phase by dissolving it into a gaseous stream (followed by dilution into the atmosphere). This is the basis of gas chromatography. As the gas flows, the decreased concentration of vapor-phase solvent molecules shifts the vapor / liquid phase equilibrium, drawing more liquid solvent into the vapor phase. By streaming the gas, the evaporation rate is increased. Evaporation systems direct a gas stream, usually of inert nitrogen, over the sample and may have the option of applying heat and agitation to the sample to help quicken the evaporation process.

[0006] The removal of solvents can be effectively accomplished by boiling. Unfortunately, many solutes such as proteins, are destroyed by the heat required to drive off solvents.However, solvents can boil by either applying heat or by lowering the atmospheric pressure. In both cases, the energy of molecular motion is greater than the intermolecular forces holding the molecules in solution. The result is that solvent molecules escape from the liquid phase to the gaseous phase. The difficulty with applying a vacuum (or applying heat) is that the force by which molecules move from liquid to gas causes the solution to splatter. This causes sample loss and / or cross contamination between samples when multiple tubes are positioned together. In vacuum concentration devices, a vacuum pump is attached to an airtight, low speed centrifuge that prevents “bumping” by forcing the liquid down into the tube. The system can then run at high vacuum levels to speed solvent removal. The vacuum concentration devices also have the option of regulating the centrifuge chamber temperature, which is useful for regulating sample temperatures at lower vacuum pressures.

[0007] Similar to vacuum concentration, the process of lyophilization goes one step further by lowering sample temperature to the point where the solution freezes and solvents are removed by sublimation. The freezing step can be done in the same preparation step or caused by the application of a vacuum, which, in the process of removing the atmosphere, also removes heat. Normally the solution is always frozen before the vacuum is applied. Lyophilization can be a relatively complex process that is usually performed in multiple stages. The first stage is sample freezing, which is critically important to the overall process. Slow freezing of a sample causes large ice crystals to form which makes freeze drying easier, but may denature many temperature sensitive proteins. Freezing a sample rapidly results in small ice crystals which can impede freeze drying, but many proteins retain activity when flash frozen.

[0008] The second stage, primary drying, occurs when the sample temperature is raised sufficiently to allow heat to flow into the frozen solution and drive the sublimation process. However during primary drying, if the temperature increases too much, the sample can thaw and “collapse.” Primary drying removes 90% or more of the solvent, at which time secondary drying, the third stage, can commence by increasing sample temperature. Secondary drying is feasible once the bulk of the solvent is removed during primary drying; the risk of melting is lessened. Secondary drying drives out residue solvent by applying greater amounts of heat. For instance, mannitol undergoes primary drying at temperatures below -23 °C (depending on the formulation) while secondary drying is as high as 40°C. Lyophilizers are an extremely effective tool for removing relatively large volumes of solvents while retaining activity of sensitive solutes. Freeze drying is very effective for concentrating and preserving biologically active proteins.

[0009] A need yet exists for a portable, low-cost, and energy efficient technology for rapidly extracting solvents from samples. It is an object of the invention to provide such systems and methods.BRIEF SUMMARY

[0010] According to a first aspect of the present disclosure, an evaporator is provided. The evaporator can comprise a channel system, a sample holder, a compressor, and a condenser. The channel system can comprise one or more channels. The sample holder can comprise a first chamber in fluid communication with the channel system and configured to hold a first sample comprising a first solvent. The compressor can be in fluid communication with the channel system and configured to cause a fluid to flow through the first chamber to cause at least a portion of the solvent in the sample to evaporate to form an at least partially saturated fluid. The condenser can be in fluid communication with the channel system and configured to receive the at least partially saturated fluid and remove, via condensation, at least a portion of the solvent in the at least partially saturated fluid to generate a dry fluid.

[0011] In any of the embodiments disclosed herein, the evaporator can further comprise a heater in fluid communication with the channel system, and the heater can be configured to heat the fluid, wherein the heated fluid causes at least a portion of the solvent in the sample to evaporate to form the at least partially saturated fluid.

[0012] In any of the embodiments disclosed herein, the channel system can form a closed loop system in which the dry fluid from the condenser is recirculated through the heater and compressor to the first chamber.

[0013] In any of the embodiments disclosed herein, the evaporator can further comprise a first filter configured to filter the fluid exiting the compressor prior to the fluid entering the first chamber.

[0014] In any of the embodiments disclosed herein, the evaporator can further comprise a second filter configured to filter the at least partially saturated fluid exiting the first chamber prior to the saturated fluid entering the condenser.

[0015] In any of the embodiments disclosed herein, the first filter and / or the second filter can be a high-efficiency particulate air (HEP A) filter.

[0016] In any of the embodiments disclosed herein, the condenser can be a thermoelectric condenser.

[0017] In any of the embodiments disclosed herein, the compressor can be selected from the group consisting of: a DC powered diaphragm pump and a DC centrifugal pump.

[0018] In any of the embodiments disclosed herein, the compressor can comprise a first nozzle configured to direct the fluid over the sample in the first chamber.

[0019] In any of the embodiments disclosed herein, the first nozzle can be an exchangeable nozzle.

[0020] In any of the embodiments disclosed herein, the sample holder can comprise one or more additional chambers, each of the one or more additional chambers configured to hold an additional sample comprising an additional solvent.

[0021] In any of the embodiments disclosed herein, the compressor can be further configured to cause at least a portion of the heated fluid to flow through the one or more additional chambers to form one or more additional at least partially saturated fluids, and the condenser can be configured to receive the one or more additional at least partially saturated fluids and remove, via condensation, at least a portion of the additional solvents in the one or more at least partially saturated fluids to generate one or more additional dry fluids.

[0022] In any of the embodiments disclosed herein, the channel system can comprise a plurality of isolated channel subsystems configured to prevent fluid flowing through the first chamber from flowing through the one or more additional chambers.

[0023] In any of the embodiments disclosed herein, the evaporator can further comprise a cleaning system configured to flow a cleaning fluid through at least a portion of the channel system, the condenser, and the sample holder. The cleaning fluid can be selected from the group consisting of: ozone, vaporized hydrogen peroxide, nebulized hydrogen peroxide, nebulized ethanol, steam, and air.

[0024] In any of the embodiments disclosed herein, the cleaning system can be configured to generate ozone from air.

[0025] In any of the embodiments disclosed herein, the heater can comprise a heating block at least partially surrounding the first chamber.

[0026] In any of the embodiments disclosed herein, the heater can be configured to heat the fluid prior to the fluid entering the first chamber.

[0027] In any of the embodiments disclosed herein, the first chamber can define a centrifuge tube.

[0028] In any of the embodiments disclosed herein, the first chamber can have a volume of between 1 femtoliter and 10,000 liters.

[0029] In any of the embodiments disclosed herein, the evaporator can be disposed in a housing and powered by a DC power source, such that the evaporator is portable.

[0030] According to a second aspect of the present disclosure, a method of evaporation is provided. The method can comprise: providing one or more samples in one or more sample chambers, each of the one or more samples comprising a solvent; directing, with a compressor, a dry fluid stream over the one or more samples in the one or more sample chambers, such that a least a portion of the solvent in the one or more samples evaporates into the dry fluid to form an at least partially saturated fluid; and condensing, with a condenser, the saturated fluid to remove at least a portion of the solvent from the saturated fluid to reform a dry fluid stream.

[0031] In any of the embodiments disclosed herein, the method can further comprise heating, with a heater, at least one of the one or more samples and the dry fluid stream.

[0032] In any of the embodiments disclosed herein, the method can further comprise, recirculating the reformed dry fluid stream from the condenser to the compressor for recirculation over the one or more samples in the one or more sample chambers.

[0033] In any of the embodiments disclosed herein, the method can further comprise filtering, with a first filter, the dry fluid stream prior to the dry fluid stream entering the one or more sample chambers and / or filtering, with a second filter, the at least partially saturated fluid stream prior to the at least partially saturated fluid stream entering the condenser.

[0034] In any of the embodiments disclosed herein, the method can further comprise cleaning, with a cleaning fluid, the one or more sample chambers.

[0035] In any of the embodiments disclosed herein, the method can further comprise catalytically converting the ozone to oxygen and releasing the oxygen to an ambient environment.

[0036] These and other aspects of the present disclosure are described in the Detailed Description below and the accompanying drawings. Other aspects and features of embodiments will become apparent to those of ordinary skill in the art upon reviewing the following description of specific, exemplary embodiments in concert with the drawings. While features of the present disclosure may be discussed relative to certain embodiments and figures, all embodiments of the present disclosure can include one or more of the features discussed herein. Further, while one or more embodiments may be discussed as having certain advantageous features, one or more of such features may also be used with the various embodiments discussed herein. In similar fashion, while exemplary embodiments may be discussed below as device, system, or method embodiments, it is to be understood that such exemplary embodiments can be implemented in various devices, systems, and methods of the present disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The following detailed description of specific embodiments of the disclosure will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the disclosure, specific embodiments are shown in the drawings. It should be understood, however, that the disclosure is not limited to the precise arrangements and instrumentalities of the embodiments shown in the drawings.

[0038] FIG. 1 provides a block diagram of a closed-loop evaporator system, in accordance with some embodiments of the present disclosure.

[0039] FIG. 2 provides an exploded view of a portion of an evaporator system, in accordance with some embodiments of the present disclosure.

[0040] FIG. 3 illustrated a fluid path through a sample holder in which dry air enters through a central inlet stream and hits the sample, collecting water vapor and becoming humid before then passing through an isolated exit channel before exiting through a central outlet stream, in accordance with some embodiments of the present disclosure.

[0041] FIG. 4 provides a plot of drying rate of a milk sample utilizing an exemplary embodiment of the present disclosure.

[0042] FIG. 5 provides an exploded view of a condenser, including a specialized dripping system, in accordance with some embodiments of the present disclosure.

[0043] FIG. 6 provides a diagram of a multi-well sample chamber in which the perimeter circles represent recesses for centrifuge tubes, while the large exterior circle represents the sample chamber, in accordance with some embodiments of the present disclosure.

[0044] FIG. 7 provides a block diagram of an open-loop evaporator system, in accordance with some embodiments of the present disclosure.

[0045] FIG. 8 provides an illustration of a portion of an evaporator for larger volume samples, allowing for air / sample interaction over a longer path to enable faster drying, in accordance with some embodiments of the present disclosure.DETAILED DESCRIPTION

[0046] Although preferred exemplary embodiments of the disclosure are explained in detail, it is to be understood that other exemplary embodiments are contemplated. Accordingly, it is not intended that the disclosure is limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The disclosure is capable of other exemplary embodiments and of being practiced or carried out invarious ways. Also, in describing the preferred exemplary embodiments, specific terminology will be resorted to for the sake of clarity.

[0047] To facilitate an understanding of the principles and features of the present disclosure, various illustrative embodiments are explained below. The components, steps, and materials described hereinafter as making up various elements of the embodiments disclosed herein are intended to be illustrative and not restrictive. Many suitable components, steps, and materials that would perform the same or similar functions as the components, steps, and materials described herein are intended to be embraced within the scope of the disclosure. Such other components, steps, and materials not described herein can include, but are not limited to, similar components or steps that are developed after development of the embodiments disclosed herein.

[0048] As used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise.

[0049] Also, in describing the preferred exemplary embodiments, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.

[0050] Ranges can be expressed herein as from “about” or “approximately” one particular value and / or to “about” or “approximately” another particular value. When such a range is expressed, another exemplary embodiment includes from the one particular value and / or to the other particular value.

[0051] Similarly, as used herein, “substantially free” of something, or “substantially pure”, and like characterizations, can include both being “at least substantially free” of something, or “at least substantially pure”, and being “completely free” of something, or “completely pure”.

[0052] By “comprising” or “containing” or “including” is meant that at least the named compound, member, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named.

[0053] Mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Similarly, it is also to be understood that the mention of one or more components in a device or systemdoes not preclude the presence of additional components or intervening components between those components expressly identified.

[0054] The materials described as making up the various members of the invention are intended to be illustrative and not restrictive. Many suitable materials that would perform the same or a similar function as the materials described herein are intended to be embraced within the scope of the invention. Such other materials not described herein can include, but are not limited to, for example, materials that are developed after the time of the development of the invention.

[0055] Reference will now be made in detail to exemplary embodiments of the disclosed technology, examples of which are illustrated in the accompanying drawings and disclosed herein. Wherever convenient, the same references numbers will be used throughout the drawings to refer to the same or like parts.

[0056] The present disclosure is generally directed to systems and methods for evaporating at least a portion of a solvent from a biological sample to yield a solute. For example, in some embodiments, a compressor is utilized to pass a relatively dry fluid, such as air, over a sample wherein a portion of the solvent in the sample is collected in the fluid. The partially saturated fluid can then pass through a condenser in which a portion of the solvent condenses and is removed from the partially saturated fluid.

[0057] Before discussing certain exemplary embodiments of the present disclosure, it may be helpful to discuss a theory behind operation of certain embodiments of the present disclosure. Some embodiments of the present disclosure control the partial pressure of solvent vapor above a sample to extract solvent from it. Even when a substance is in its liquid state, it still exists in equilibrium with its gaseous state, i.e., vapor. This equilibrium is observed in all materials, even in their solid state. While herein there is a primary reference to aqueous (water) solutions, the innovative mechanism is applicable to a wide range of liquids with melting points in a broad range of temperatures (-60°C to 150°C), including industrially relevant solvents such as tert- Butyl alcohol, benzene, carbon tetrachloride, etc.

[0058] The saturation vapor pressure (saturation pressure) of a liquid can be defined as the partial pressure exerted by its vapor in thermal equilibrium with its liquid state. This dynamic equilibrium can be maintained by the evaporation of the liquid or condensation of the vapor as necessary to ensure that the partial pressure is equal to the saturation pressure of the liquid. Removing the vapor can cause the liquid to evaporate faster (by Le Chatelier’s principle).

[0059] In lyophilization and centrifugal vacuum evaporation, a vacuum is used to remove the gas. However, the high vacuum required necessitates the use of a bulky, power-intensive vacuum pump and chamber.

[0060] Embodiments of the present disclosure can remove the vapor without a vacuum by leveraging the temperature dependence of the saturation pressure. This design can allows the evaporator systems disclosed herein to be small, portable, and power efficient.

[0061] The principles of the present disclosure include the definition of relative humidity (f> of a gas as:Equation 1:where pwater is the partial pressure of water vapor, and plater is the saturation pressure of water at that temperature. The saturation pressure of water rises exponentially with temperature, which enables the following effective method to generate gas with low relative humidity (i.e., dry gas).

[0062] Consider a packet of gas initially (step 1) at a temperature THwith 100% relative humidity, pwater,i = Pwater(Tn)- If it iscooled (step 2) to a temperature Tc(Tc< TH). the saturation vapor pressure of water decreases exponentially, causing the water vapor in the gas to condense until the relative humidity is at 100%, i.e., pwater,2=Pwater Tc)-

[0063] Suppose the condensed water is removed, and then the gas is heated (step 3) back to THwhile maintaining constant volume. Accounting for the pressure increase due to the temperature rise using the ideal gas law, we get the new relative humidity:Equation 2:

[0064] THis chosen to be the maximum temperature that the sample can be expected to tolerate without degradation, since higher temperatures lead to exponentially faster evaporation.

[0065] We choose 40°C since the human body can remain at this temperature for extended periods without denaturing its biomolecules. A typical configuration for the present invention for a patient sample would be Tc= 10°C and TH= 40°C, with p(vater(10°C) = 1.23 kPa and Pwater (40°C) = 7.38 kPa. This cycle gives us a gas with a final relative humidity of 18%, hence removing 82% of the water from the original gas.

[0066] This principle is also independent of the carrier gas. Various embodiments of the present disclosure can thus use different gases, including nitrogen, argon, carbon dioxide, etc., to run this cycle in different contexts.

[0067] FIG. 1 provides an exemplary evaporator system in a “closed-loop” fluid circulation configuration. The evaporator can comprise a condenser 125, compressor 105, 110 heater 110, first filter 115, sample chamber 120, second filter 116, cleaning fluid source 130, pump 135, and nebulizer 140. A channel system (denoted by the interconnecting solid and dashed lines) can provide for fluid communication between the various components of the evaporator. The interconnecting lines are shown in both solid and dashed forms representing relatively humid / saturated and dry fluids, respectively.

[0068] The sample chamber 120 configured to hold a first sample comprising a first solvent. The compressor 105, e.g., a direct current (“DC”) powered diaphragm pump and a DC centrifugal pump, can be configured to cause a relatively dry fluid to flow through the chamber 120 to cause at least a portion of the solvent in the sample to evaporate to form an at least partially saturated fluid (e.g., relatively humid fluid as compared to the dry fluid exiting the compressor 105). The condenser 125 can be configured to receive the at least partially saturated fluid and remove, via condensation, at least a portion of the solvent in the at least partially saturated fluid to generate (or regenerate) a relatively dry fluid (as compared to the partially saturated fluid). The heater 110 can be configured to heat the fluid exiting the compressor 105. In some embodiments, the heater can directly heat the fluid as it passes through the heater or indirectly heat the fluid by heating the sample chamber 120, for example, by heating a heating block surrounding at least a portion of the chamber 120. The heated fluid can cause at least a portion of the solvent in the sample to evaporate into the dry fluid to form the at least partially saturated fluid.

[0069] The term “heater,” as used herein is not limited to only devices that can increase the temperature of the fluid / sample Rather, the term “heater” should be broadly construed as any device capable of temperature regulation, whether heating or cooling the fluid. For example, For example, consider the case where ambient temperature is at 35°C, while it is desirable for the sample temperature to never exceed 25°C. In such a scenario, the “heater” can be used to dissipate heat, i.e., cool, the sample and or fluid such that its temperature does not exceed the desired temperature.

[0070] As shown in FIG. 1 , the channel system can form a closed loop system in which the dry fluid exiting the condenser 125 is recirculated through the compressor 105 (and optionally heater 110) to the sample chamber 120 to continue the solvent evaporation process.

[0071] The first filter 115 and second filter 116 can be utilized to prevent contamination to and from the sample chamber. For example, the first filter can filter the dry fluid from thecompressor / heater prior to entering the sample chamber 120, and the second filter 116 can filter the partially saturated fluid exiting the chamber 120 prior to the partially saturated fluid entering the condenser 125. The filters can be many filters known in the art, including, but not limited to, high-efficiency particulate air (HEP A) filters.

[0072] In some embodiments, to prepare for the next sample run, the system can be sterilized / cleaned with an optional cleaning system. The cleaning fluid source 130, pump 135, and nebulizer 140 can form a cleaning system. The cleaning fluid can be many cleaning fluids known in the art, including, but not limited to, ozone, vaporized hydrogen peroxide, nebulized hydrogen peroxide, nebulized ethanol, steam, and air. The pump 135 can pump the cleaning fluid from the source 130 to the nebulizer 140 (e.g., a piezoelectric nebulizer), wherein the cleaning fluid can be nebulized into a fine mist prior to entering the channel subsystem for circulation through one or more of the chamber 120, condenser 125, compressor 105 and heater 110. Circulation can be aided by the compressor 105. Because some cleaning fluids can harm the filters, in some embodiments, an alternate air path that skips the filters can be utilized.

[0073] In some embodiments, the cleaning system can be configured to generate ozone from air either ambient to the evaporator or internal to the evaporator. The cleaning system can further be configured to catalytically convert the ozone to oxygen where it can be safely released to into the atmosphere. The ozone generation and catalytic conversion processes are well understood by those skilled in the art. For example, in some embodiments, a high electric field can be applied across air (comparable to or greater than the dielectric breakdown voltage of air, 30 kV / cm), and pass air through. A dielectric like glass may be placed between the two electrodes to prevent arcing while ensuring ozone generation.

[0074] FIG. 2 provides an exploded view of an exemplary sample chamber in accordance with some embodiments of the present disclosure. Air / fluid enters the sample chamber 120 via a central inlet stream 205 into nozzles, which are shown in FIG. 2 as standard disposable filter pipette tips 210, which are placed at the top of the sample chamber 120 and held in place by a pipette tip stabilizer 21 1. These tips 210 can come pre-fitted with aerosol filters capable of filtering bacteria, viruses, DNA, etc. and can be easily exchanged between evaporator run cycles. These filters can block contamination from the environment and compressor from reaching the samples. The pipette tips 210 can be replaced between runs to prevent run-to-run sample contamination.

[0075] In some embodiments, the nozzles (e.g., pipette tips 210) can have an adjustable height, in which the height can be adjusted before or during the evaporation process toimprove the drying speed. This feature can be accomplished, for example, through the use of flexible pipes connecting the nozzles to the compressor 105.

[0076] The samples can be placed within standard centrifuge tubes 215, which are then placed in a thermally conductive heating block 220. The heating block 220 has cavities that mold closely to the centrifuge tubes 215 to allow for optimal heat transfer between the sample and the block 220. Peltier elements 225 can be mounted to the bottom of the heating block 220. Combined with a thermocouple (not shown) attached to the middle of the heating block, this enables precise control of the block temperature. The block 220 and chamber 120 are thermally insulated to minimize heat wastage. In case the environment is warmer than the desired cycle TH„ this block 220 may also be cooled by the same Peltier elements 225. A heatsink and fan (not shown) can then be used to dump waste heat into the atmosphere.

[0077] As the warm, dry air passes through the sample chamber 120, each pipette / nozzle 210 directs it into a jet that blows onto the sample. This air collects solvent vapor from the sample. To enable multiple specimens to be dried simultaneously, airtight barriers can be placed around the heating block 220 to create isolated chambers and prevent crosscontamination. Thus, the evaporator can be utilized to evaporate multiple samples containing the same or different solvents, which can be isolated from each other The now humid air exits through isolated exit channels 230 in the housing, which then lead to the central exit stream 235. These channels 230 can prevent sample cross-contamination due to downstream turbulent mixing. The air path through the exemplary sample chamber is depicted in FIG. 3.

[0078] After the air / fluid passes through the chamber 120 and, optionally, filter 116, the air passes through the condenser 125. An exemplary thermoelectric condenser is shown in FIG. 5. The condenser 125 can be thought of fundamentally as a thermally conductive chamber that is kept colder than the sample chamber using another Peltier element 505. A heatsink 510 and fan 515 can be mounted to this Peltier element to enable it to efficiently dump heat into the atmosphere. The lower temperature in the chamber causes water from the air to condense inside this chamber. The chamber can be thermally insulated to help maintain this lower temperature. In some embodiments, the chamber can be at least 20°C colder than the sample chamber to enable efficient moisture capture. The condensed water then exits the chamber through a dripping system.

[0079] An exemplary dripping system is shown in FIG. 5 and can comprise an inlet 518, outlet 319, and openings 520 (drip holes) in the condenser chamber 522, from which a pipe directs the water flow into a drip tank 530. However, a key feature of the exemplary dripping system is that it can prevent air from flowing in or out through this pipe, which would decrease the overall efficiency of the system. This reduction in efficiency could be either through allowing the pressurized air to exit the loop, leading to a loss in airflow speed, or through humid external air entering the condenser unit directly, which may force the condenser to expend more energy in removing this humidity. The system can block this airflow by placing a porous material 525 (such as filter paper or Kimwipes) at the opening in the chamber. In some embodiments, the porous material can have a height / thickness greater than a capillary height of the solvent being condensed (i.e., the maximum height up to which the solvent will rise vertically in that porous material). This is because, if the height / thickness is less, then the porous material might wick up the condensed solvent but not let it drip, limiting the total solvent carrying capacity of the condenser.This may only partially restricts airflow in the beginning when the chamber is dry. However, as water collects in the chamber, it fills up the pores in this porous material, making it substantially impervious to air and completely restricting airflow. Thus, airflow is contained within the main loop and returns to the compressor, repeating the cycle. In some embodiments, the condenser can be oriented vertically, such that the solvent will drip down through the porous material into the collection chamber via gravitational forces. This system also enables convenient recovery of solvents into the drip tank.

[0080] The Peltier element 505 used for cooling the condenser 125 can also be run in reverse to heat it. This allows any residual water in the condenser 125 to be dried for storage or transport of the device.

[0081] The evaporator can be much smaller and operate with lower power DC components disposed in a singular housing (as would be understood by those skilled in the art), making it portable, which provides many advantages over conventional evaporation systems.

[0082] FIG. 6 provides an alternative embodiment of a sample chamber in which multiple wells are disposed around the perimeter of the chamber. These wells can be formed by recesses for holding centrifuge tubes.

[0083] FIG. 7 provides an alternative block diagram of a evaporator arranged in an “openloop” configuration, which can be advantageous for applications where the sample cannotbe placed inside a centrifuge tube, such as for drying a drop of sample onto a slide, drying hair, etc., in which a form factor similar to a blow-dryer is preferable. Generally, in such cases, sterility is not required. Importantly, the humid air coming from the sample cannot be efficiently collected. Thus, instead of adopting the cyclic drying process from FIG. 1, a linear process (FIG. 7) can be utilized where fresh air is collected from the atmosphere and directed at the sample using a nozzle of appropriate dimensions.

[0084] FIG. 8 provides an embodiment for use when it is desirable to dry larger volumes (e.g., >10mL) quickly and efficiently. This embodiment can provide for a larger surface area available for drying. Here, either an open or closed loop process can be used. The salient modification in this embodiment is that air is directed at the sample using a skirt 805 instead of a nozzle. The sample can be held in a wide dish 810 (such as a Petri dish) instead of a tall centrifuge tube. The air flows horizontally across the sample (FIG. 8), which has a much larger surface area to volume ratio in this configuration. This enables the dry air to interact with the sample over a longer path length and pick up more moisture, enabling faster drying. This system can be used to quickly concentrate large volumes of biofluids. As discussed in the commercial applications section, this can be used, for instance, to concentrate airborne pathogens extracted from masks using relatively large quantities of water (50-100 mL). This could also be used to rapidly extract solvents on materials being transported using a conveyor belt. This can be particularly useful in reel-to-reel manufacturing, where it may be desirable to soak the substrate in a solvent and then quickly remove it. If using the cyclic “closed-loop” process (FIG. 1), the solvent can be recovered, making it more cost-effective to use larger quantities of solvent.

[0085] The evaporators disclosed herein can be made, at least in part, of many thermally conductive materials, including metals, such as milled aluminum or copper. However, CNC milling can be expensive. Thus, some embodiments utilize a cheaper method of using a thin (~l-2 mm) polymer shell filled with thermally conductive particulates such metal balls, powder, or filings, which are easily available at low cost. The shell may also be filled with a liquid, in which case convection will facilitate heat exchange. Ideally, the liquid would have relatively low viscosity and vapor pressure, such as mineral oil. A combination of these approaches may also be used. The polymer shell can be easily produced into the desired shape using methods such as 3D printing, blow-molding, etc.This approach offers lower thermal conductivity than solid metal but can be acceptable for some use cases.

[0086] It is to be understood that the embodiments and claims disclosed herein are not limited in their application to the details of construction and arrangement of the components set forth in the description and illustrated in the drawings. Rather, the description and the drawings provide examples of the embodiments envisioned. The embodiments and claims disclosed herein are further capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purposes of description and should not be regarded as limiting the claims.

[0087] Accordingly, those skilled in the art will appreciate that the conception upon which the application and claims are based may be readily utilized as a basis for the design of other structures, methods, and systems for carrying out the several purposes of the embodiments and claims presented in this application. It is important, therefore, that the claims be regarded as including such equivalent constructions.

[0088] Furthermore, the purpose of the foregoing Abstract is to enable the United States Patent and Trademark Office and the public generally, and especially including the practitioners in the art who are not familiar with patent and legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract is neither intended to define the claims of the application, nor is it intended to be limiting to the scope of the claims in any way.

Claims

CLAIMSWhat is claimed is:

1. An evaporator, comprising: a channel system comprising one or more channels; a sample holder comprising a first chamber in fluid communication with the channel system and configured to hold a first sample comprising a first solvent; a compressor in fluid communication with the channel system, the compressor configured to cause a fluid to flow through the first chamber to cause at least a portion of the solvent in the sample to evaporate to form an at least partially saturated fluid; and a condenser in fluid communication with the channel system, the condenser configured to receive the at least partially saturated fluid and remove, via condensation, at least a portion of the solvent in the at least partially saturated fluid to generate a dry fluid.

2. The evaporator of claim 1 , further comprising a heater in fluid communication with the channel system, the heater configured to heat the fluid, wherein the heated fluid causes at least a portion of the solvent in the sample to evaporate to form the at least partially saturated fluid.

3. The evaporator of claim 1, wherein the channel system forms a closed loop system in which the dry fluid from the condenser is recirculated through the heater and compressor to the first chamber.

4. The evaporator of claim 1, further comprising a first filter configured to filter the fluid exiting the compressor prior to the fluid entering the first chamber5. The evaporator of claim 4, wherein the first filter is a high-efficiency particulate air (HEP A) filter.

6. The evaporator of claim 4, further comprising a second filter configured to filter the saturated fluid exiting the first chamber prior to the at least partially saturated fluid entering the condenser.

7. The evaporator of claim 6, wherein the second filter is a high-efficiency particulate air (HEP A) filter.

8. The evaporator of claim 1, wherein the condenser is a thermoelectric condenser.

9. The evaporator of claim 1 , wherein the compressor is selected from the group consisting of: a DC powered diaphragm pump and a DC centrifugal pump.

10. The evaporator of claim 1, wherein the compressor comprises a first nozzle configured to direct the fluid over the sample in the first chamber.

11. The evaporator of claim 10, wherein the first nozzle is an exchangeable nozzle.

12. The evaporator of claim 1 , wherein the sample holder comprises one or more additional chambers, each of the one or more additional chambers configured to hold an additional sample comprising an additional solvent.

13. The evaporator of claim 12, wherein the compressor is further configured to cause at least a portion of the heated fluid to flow through the one or more additional chambers to form one or more additional at least partially saturated fluids, and wherein the condenser is configured to receive the one or more additional at least partially saturated fluids and remove, via condensation, at least a portion of the additional solvents in the one or more at least partially saturated fluids to generate one or more additional dry fluids.

14. The evaporator of claim 13, wherein the channel system comprises a plurality of isolated channel subsystems, the isolated channel subsystems configured to prevent fluid flowing through the first chamber from flowing through the one or more additional chambers.

15. The evaporator of claim 1, further comprising a cleaning system configured to flow a cleaning fluid through at least a portion of the channel system, the condenser, and the sample holder.

16. The evaporator of claim 15, wherein the cleaning fluid is selected from the group consisting of: ozone, vaporized hydrogen peroxide, nebulized hydrogen peroxide, nebulized ethanol, steam, and air.

17. The evaporator of claim 16, wherein the cleaning fluid is ozone, and wherein the cleaning system is configured to generate ozone from air.

18. The evaporator of claim 1, wherein the heater comprises a heating block at least partially surrounding the first chamber.

19. The evaporator of claim 1 , wherein the heater is configured to heat the fluid prior to the fluid entering the first chamber.

20. The evaporator of claim 1, wherein the first chamber defines a centrifuge tube.

21. The evaporator of claim 1, wherein the first chamber has a volume of between 1 femto liter and 10,000 liters.

22. The evaporator of claim 1 , wherein the evaporator is disposed in a housing and powered by a DC power source, such that the evaporator is portable.

23. A method of evaporation, comprising: providing one or more samples in one or more sample chambers, each of the one or more samples comprising a solvent;directing, with a compressor, a dry fluid stream over the one or more samples in the one or more sample chambers, such that a least a portion of the solvent in the one or more samples evaporates into the dry fluid to form an at least partially saturated fluid; and condensing, with a condenser, the saturated fluid to remove at least a portion of the solvent from the saturated fluid to reform a dry fluid stream.

24. The method of claim 23, further comprising heating, with a heater, at least one of the one or more samples and the dry fluid stream.

25. The method of claim 23, further comprising recirculating the reformed dry fluid stream from the condenser to the compressor for recirculation over the one or more samples in the one or more sample chambers.

26. The method of claim 23, further comprising filtering, with a first filter, the dry fluid stream prior to the dry fluid stream entering the one or more sample chambers.

27. The method of claim 26, wherein the first filter is a high-efficiency particulate air (HEP A) filter.

28. The method of claim 23, further comprising filtering, with a second filter, the at least partially saturated fluid stream prior to the at least partially saturated fluid stream entering the condenser.

29. The method of claim 28, wherein the second filter is a high-efficiency particulate air (HEP A) filter.

30. The method of claim 23, wherein the condenser is a thermoelectric condenser.

31. The method of claim 23, wherein the compressor is selected from the group consisting of: a DC powered diaphragm pump and a DC centrifugal pump.

32. The method of claim 23 , wherein the compressor comprises, for each of the one or more sample chambers, a nozzle configured to direct the dry fluid stream over the sample in the respective sample chamber.

33. The method of claim 23, further comprising, cleaning, with a cleaning fluid, the one or more sample chambers.

34. The method of claim 33, wherein the cleaning fluid is selected from the group consisting of: ozone, vaporized hydrogen peroxide, nebulized hydrogen peroxide, nebulized ethanol, steam, and air.

35. The method of claim 34, wherein the cleaning fluid is ozone, the method further comprising generating the ozone from air.

36. The method of claim 35, further comprising, catalytically converting the ozone to oxygen and releasing the oxygen to an ambient environment.

37. The method of claim 23, wherein each of the one or more sample chambers have a volume of between 1 femtoliter and 10,000 liters.

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