TEM grids with liquid spreading lanes

Abstract

To provide a grid for sampling a liquid specimen for transmission electron microscopy (TEM) analysis.SOLUTION: A grid for sampling a liquid specimen includes a first layer and a backing material supporting the first layer. The first layer includes a plurality of lanes. Each lane has a first end configured to receive a droplet of the liquid specimen, a second end opposite the first end, and a length extending from the first end to the second end. The applicator is configured to apply a droplet of the liquid specimen onto each lane such that a spontaneous capillary flow of the liquid specimen occurs.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a grid for sampling a liquid sample. The grid may be for sampling a liquid sample for transmission electron microscope (TEM) analysis. [Background technology]

[0002] Samples for single particle cryo-electron microscopy are traditionally prepared by manually pipetting a buffer solution containing the protein onto a TEM grid carrier. The grid is then blotted with filter paper and vitrified in liquid ethane. In this process, a few microliters of sample can be applied to wet the entire grid, and then 99.99% of it is removed. In addition, different blotting conditions (e.g., variations in blotting force and irregular patterns of fibers in the filter paper) can result in unpredictable sample thickness.

[0003] To eliminate the blotting step, alternative methods of sample preparation have been developed. Some techniques dispense liquid in a controlled but very localized manner, such as piezoelectric inkjet dispensing, pin printing techniques, and microcapillary writing. Other techniques use a spray to cover the entire grid, but can suffer from droplet size and position distribution, as well as sample loss. Summary of the Invention

[0004] In one implementation, the present disclosure provides a grid for sampling a liquid sample. The grid includes a first layer and a backing material supporting the first layer. The first layer includes a plurality of lanes, each lane having a first end configured to receive a droplet of the liquid sample, a second end opposite the first end, and a length extending from the first end to the second end.

[0005] In another implementation, the present disclosure provides a transmission electron microscope (TEM) sample preparation system including a grid and an applicator. The grid is configured to sample a liquid sample. The grid includes a first layer having a plurality of lanes and a backing material supporting the first layer, each lane having a first end configured to receive a liquid sample, a second end opposite the first end, and a length extending from the first end to the second end. The backing material defines a bottom of each lane. The applicator is configured to apply a droplet of the liquid sample onto each lane such that spontaneous capillary flow of the liquid sample occurs.

[0006] In another implementation, the present disclosure provides a method of preparing a liquid sample. The method includes providing a grid. The grid includes a first layer having a plurality of lanes and a backing material supporting the first layer, each lane having a first end configured to receive a liquid sample, a second end opposite the first end, and a length extending from the first end to the second end. The backing material defines a bottom of each lane. The method further includes applying a droplet of a liquid sample onto the first end of each of the plurality of lanes such that the plurality of lanes are filled via spontaneous capillary flow.

[0007] Other aspects of the disclosure will become apparent by consideration of the detailed description and accompanying drawings. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is an exploded schematic view of a grid for sampling a liquid sample. [Diagram 2] FIG. 2 is a schematic top view of a lane of the grid of FIG. 1. [Figure 3A] FIG. 4 is a cross-sectional view of the lane of FIG. 2 taken along line 4-4. [Figure 3B] FIG. 13 is a cross-sectional view of another embodiment of a lane. [Figure 4] FIG. 13 is a cross-sectional view of another embodiment of a lane. [Figure 5A]FIG. 13 is a top schematic view of another embodiment of a lane of a grid. [Figure 5B] FIG. 13 is a top schematic view of another embodiment of a lane of a grid. [Figure 5C] FIG. 13 is a top schematic view of another embodiment of a lane of a grid. [Figure 6] 4 is a cross-sectional perspective view of the lane of FIG. 2 taken along line 4-4 of FIG. 2. [Figure 7] 1 is a schematic diagram of an electronic control system and a printer. [Figure 8] 1 is a flow chart showing a method for preparing a liquid sample. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Before any implementations of the present disclosure are described in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other implementations and of being practiced or carried out in various ways.

[0010] The present disclosure relates to a sample preparation system 10 for sampling a liquid sample 14. The sample preparation system 10 is configured to prepare the liquid sample 14 for analysis in a particular charged microscopy technique, such as by a transmission electron microscope (TEM). The illustrated application is by way of example only, and the sample preparation system 10 may be utilized in any sampling application, particularly when sampling a liquid sample 14.

[0011] As shown in FIGS. 1-3, the sample preparation system 10 includes an applicator (further referred to as an inkjet printer 18) for applying or printing the liquid sample 14, and a grid 22 for holding the liquid sample 14. The inkjet printer 18 is configured to print multiple droplets 26 of the liquid sample 14 onto the grid 22. The printer may precisely print the droplets 26 such that the volume of the printed droplet is substantially the same as the volume of the portion of the grid 22 that the droplet 26 fills. That is, the droplets 26 are precisely printed so as not to overflow the grid 22 or to underfill the grid 22. In other embodiments, the liquid sample 14 may overfill the grid 22. In other embodiments, a different device (e.g., a pipette, a capillary, a syringe, etc.) may be used to place the liquid sample 14 on the grid 22. The volume of the droplets 26 may be less than 1 nanoliter to obtain a desired film height. The printer 18 may print one droplet 26 or multiple droplets 26 onto the grid 22. The printer 18 is configured to print droplets 26 onto the front side 34 of the grid 22. In an alternative embodiment, the printer 18 may print droplets 26 onto the back side 38 of the grid 22. Each droplet 26 of liquid sample 14 applied to the grid 22 has a droplet size 97. In the illustrated embodiment, the droplet size 26 is approximately 23 picoliters. For example, the droplet size 97 may range from 1 picoliter to 1 nanoliter. In other embodiments, the droplet size 97 may be larger or smaller.

[0012] The grid 22 includes a backing material 40 and a first layer 42. The backing material 40 may be any of a number of different materials (e.g., foil, metal, plastic, ceramic, silicon nitride). The backing material 40 defines the back side 38 of the grid 22, and the first layer 42 defines the front side 34 of the grid 22. The backing material 40 and the first layer 42 are substantially the same shape and size. In the illustrated embodiment, both the backing material 40 and the first layer 42 are circular. In alternative embodiments, the first layer 42 and the backing material 40 may be different shapes (e.g., square, rectangular, trapezoidal, etc.) or the first layer 42 may have a different shape than the backing material 40 (e.g., the first layer 42 may be circular and the backing material 40 may be square).

[0013] In the illustrated embodiment, the first layer 42 is hydrophilic and the backing material 40 is hydrophilic. In alternative embodiments, the first layer 42 may not be hydrophilic and / or the backing material 40 may not be hydrophilic.

[0014] The first layer 42 includes a plurality of slots 46. Each slot 46 defines a lane 50. The lanes 50 are configured to separate each droplet 26 of the liquid sample 14 such that multiple samples may be received on the grid 22. In some embodiments, each lane 50 may receive a different sample. In other embodiments, each lane 50 may receive the same sample. For example, a first liquid sample may be disposed in a first half 52 of the plurality of lanes 50, and a second liquid sample may be disposed in a second half 53 of the plurality of lanes 50. In some embodiments, each lane 50 may receive multiple liquid samples 50. Alternatively, each of the plurality of lanes 50 may receive a different liquid sample 14. In other embodiments, two or more different liquid samples 14 may be disposed within a single lane 50. In some embodiments, the lane 50 may have a single inlet configured to be fed by a single droplet 26. Alternatively, the multiple inlets may be fed by different droplets 26 and configured to direct the droplets 26 to the single lane 50. Evaporation may be closely monitored and controlled while the printer 18 prints droplets 26 into each lane 50 to prevent one lane 50 from drying out before the next lane 50 is filled with liquid sample 14.

[0015] With respect to the orientation of the grid 22 shown in FIG. 1 , the first layer 42 has a left edge 54, a right edge 58, a top edge 62, and a bottom edge 66. A first axis 70 extends through the top edge 62 and the bottom edge 66. The first axis 70 may also be referred to as a longitudinal axis or a vertical axis. A second axis 74 extends through the left edge 54 and the right edge 58. The second axis 74 may also be referred to as a latitudinal axis or a horizontal axis. A solid portion 78 of the first layer 42 coincides with the latitudinal axis 74. A first set 82 of lanes 50 is located above the solid portion 78, and a second set 86 of lanes 50 is located below the solid portion 78. Each set of lanes 82, 86 extends from the solid portion 78 toward the periphery of the first layer 42. The lanes 50 are spaced apart from the periphery such that each lane 50 is completely bounded by the first layer 42. The first set 82 and the second set 86 are mirror images of each other across the latitudinal axis 74. Because the first layer 42 is circular, the lanes 50 closest to the left edge 54 and the lanes 50 closest to the right edge 58 have a shorter length 90 than the lanes 50 near the center of the first layer 42. The lanes 50 increase in length toward the longitudinal axis 70. In the illustrated embodiment, the first layer 42 has 42 total lanes 50 (e.g., 21 lanes in the first set 82 and 21 lanes in the second set 86). In other embodiments, the first layer 42 may have fewer or more total lanes 50 and / or the first and second sets 86 may have different numbers of lanes 50. As described below (see FIGS. 5B and 5C), in some embodiments, the lanes 50 may have different shapes or different patterns. For example, the lanes 50 may curve or radiate outward from a single entrance.

[0016] Referring to FIG. 2, in this embodiment, the lanes 50 are linear. Each of the plurality of lanes 50 has a first end 98 and a second end 99. The first end 98 is configured to receive droplets 26 from the printer 18. The second end 99 is located opposite the first end 98 and may be configured to receive a second droplet of the same liquid sample 50 or a second droplet of a second liquid sample. Each lane 50 further has a length 100 extending from the first end 98 to the second end 99. Each lane 50 further includes a rounded portion 126 at the first end 98. The rounded portion 126 is larger than the remainder of the lane 50 to facilitate receiving the droplets 26. The lane 50 thereby defines a flow path of the liquid sample 14 from the first end 98 to the second end 99. In other embodiments, the lane 50 may not include the rounded portion 126, and the droplets 26 may be printed directly into the lane 50. Alternatively, the rounded portion 126 may be any of a number of different shapes (e.g., triangular, square, etc.).

[0017] In some embodiments (see Figures 3A and 3B), the first layer 42 may be a mesh 42 A. In an alternative embodiment (see Figure 4), the first layer 42 may be a silicon nitride foil 42B and the backing material 40 may be a silicon wafer 40B upon which the silicon nitride foil 42B is suspended.

[0018] As shown in FIG. 3A, the mesh 42A includes a plurality of bars 101. The bars 101 define the sidewalls 106 of each lane 50. In the illustrated embodiment, the bars 101 extend parallel to one another such that the lanes are parallel to one another. Each bar 101 has a bar height 114. The bar height 114 corresponds to the mesh thickness 95. The backing material 40 is bonded to the mesh 42A and defines the bottom 110 of the lane 50. The illustrated backing material further defines holes 102. The holes 102 are significantly smaller than each lane 50 such that the plurality of holes 102 fit across the width of each lane 50. The holes 102 may be specifically positioned along the lane 50 such that the holes 102 do not overlap the bars 101 to prevent leakage of the liquid sample 14. Alternatively, the backing material 40 may have a less hydrophilic nature than the mesh 42A to prevent leakage of the liquid sample 14.

[0019] The mesh 42A has a mesh thickness 95 and the backing material 40 has a backing thickness 96. In the illustrated embodiment, the mesh thickness 95 is about 15 micrometers and the backing thickness 96 is about 10 nanometers. For example, the mesh thickness 95 may be in the range of 5-35 micrometers and the backing thickness 96 may be in the range of 5-50 nanometers. In other embodiments, the mesh thickness 95 and / or backing thickness 96 may be thicker or thinner.

[0020] 3A and 3B, each bar 101 defines a sample thickness 122 of the liquid sample 14. The sample thickness 122 in this embodiment varies between each bar 101 or sidewall 106. The sample thickness 122 may vary between 1 micrometer and 10 micrometers. In other embodiments, the sample thickness 122 may have other nominal thicknesses. The sample thickness 122 varies between the sidewalls 106 as the liquid sample 14 defines a concave meniscus within the lane 50. In other embodiments, the sample thickness 122 may be constant or convex (i.e., in the case of overfill). In the embodiment of FIG. 3A, each bar 101 includes a ridge 124 relative to the backing material 40. The ridge 124 limits the sample thickness 122 such that the sample thickness 122 is less than the thickness of the mesh thickness 95. In other embodiments, such as the embodiment shown in FIG. 3B, the bar 101 does not include the ridge 124. In this embodiment, the portion of the thickness 123 of the liquid sample 14 closest to the bar 101 is the same as the mesh thickness 95. Alternative embodiments may use different features to limit the thickness 122 of the liquid sample 14. For example, portions of the bar 101 may be hydrophobic to limit the thickness 122.

[0021] In the embodiment shown in FIG. 4, the first layer 42 is a silicon nitride foil 42B. The foil 42B is suspended over a silicon wafer 40B with lanes 50 etched into the foil 42B. Specifically, the lanes 50 are etched into the foil 42B without breaking through the bottom wall 43 of the foil 42B. The side walls 106 may be formed during etching of the lanes 50 into the foil 42B. In some embodiments, multiple holes (not shown) may be etched into the bottom wall 43 of each lane 50. The holes may be of a similar width to each lane 50 such that each lane 50 may fit only a single hole across the width of the lane. In some embodiments, multiple holes may be etched across the width of each lane 50.

[0022] The foil 42B has a foil thickness 63, the wafer 40B has a wafer thickness 64, and the lanes 50 have a lane thickness 65. In the illustrated embodiment, the foil thickness is about 350 nanometers, the wafer thickness is about 100 micrometers, and the lane thickness is about 300 nm. The foil thickness 63 may be in the range of 100-500 nanometers, the wafer thickness 64 may be in the range of 50-300 micrometers, and the lane thickness 65 may be in the range of 100-500 nanometers. In other embodiments, the foil thickness 63, the wafer thickness 64, and / or the lane thickness 65 may be thicker or thinner. The wafer thickness 64 is configured to be significantly greater than the foil thickness 63 to provide robust support and rigidity for the foil 42B.

[0023] In this embodiment, the lane thickness 65 may be between 100 and 500 nanometers. Thus, the sample thickness 122 may similarly vary between 100 and 500 nanometers. In other embodiments, the sample thickness 122 may have other nominal thicknesses. The sample thickness 122 varies between the sidewalls 106 as the liquid sample 14 defines a concave meniscus within the lane 50. In other embodiments, the sample thickness 122 may be constant or convex (i.e., in the case of overfill). In this embodiment, the liquid sample 14 may overfill the grid 22 due to the lane thickness 65.

[0024] 5A-5C, the lanes 50 may have different shapes. For example, the lane 50A (FIG. 5A) may be straight, the lane 50B (FIG. 5B) may be curved 50B, or the lane 50C (FIG. 5C) may be tapered 50C. The straight lanes 50A are similar to the lanes 50 shown in FIGS. 1 and 2. Each straight lane 50A extends generally parallel to one another. In alternative embodiments, the straight lanes 50A may extend laterally relative to one another. For example, the straight lanes 50A may radiate from a central portion of the grid 22. Alternatively, some of the straight lanes 50A may extend parallel to the longitudinal axis 70 and some of the linear lanes 50A may extend perpendicular to the longitudinal axis 70. In alternative embodiments, the lane 50 may branch from a single lane into multiple lanes. The multiple lanes may have the same width and height as the single lane, or may have different widths or heights. Additionally, each of the multiple lanes may have a different width or height compared to one another.

[0025] As shown in FIG. 5B, each curved lane 50B includes a first portion 111, a second portion 112, and a third portion 113. The first portion 111 and the third portion 113 are generally straight and parallel. In alternative embodiments, the first portion 111 and the third portion 113 may be substantially transverse. The second portion 112 is between the first portion 111 and the third portion 113. The second portion 112 defines a bend 115 configured to bend and change the direction of the flow path of the liquid sample 14 such that the liquid sample 14 in the first portion 111 follows a first flow path 116 and the liquid sample 14 in the third portion 113 follows a second flow path 117. In some embodiments, the curved lane 50B may include one bend or multiple bends (e.g., the lane 50B may be S-shaped or serpentine).

[0026] As shown in FIG. 5C, each tapered lane 50C includes a first end 98C having a first width 118 and a second end 99C having a second width 119. The first width 118 is greater than the second width 119 such that the width of the tapered lane 50C decreases from the first end 98C to the second end 99C. In the illustrated embodiment, the tapered lane 50C tapers continuously from the first end 98C to the second end 99C. More specifically, the tapered lane 50C tapers linearly from the first end 98C to the second end 99C. In other embodiments, the tapered lane 50C may taper non-linearly and / or non-continuously between the first end 98C and the second end 99C. In alternative embodiments, the second width 119 may be greater than the first width 118 such that the width of the lane 50C increases from the first end 98 to the second end 99 .

[0027] 6, each lane 50 has a width 130 and a height 134. The width 130 is defined by the distance between each bar 101. The height 134 is defined by the height 114 of the bars. The width 130 and the height 134 may define any of a number of aspect ratios. The aspect ratio and hydrophilicity of the grid 22 cause spontaneous capillary filling (SFC) to occur. In some embodiments, each lane 50 may have a different width 130 and / or height than the other lanes 50. Additionally, each lane 50 may have a different shape.

[0028] For SFC to occur, the aspect ratio may be less than a critical aspect ratio determined by the contact angle between the liquid and the walls of the lane 50. For example, assuming a constant contact angle of 30 degrees, the critical aspect ratio is estimated to be 13. Alternatively, assuming a constant contact angle of 20 degrees, the critical aspect ratio is estimated to be 31. Other critical aspect ratios are obtained for other contact angles or non-uniform contact angles (i.e., different contact angles of the first layer 42 and the foil 40). In accordance with the principles of SFC, the droplet 26 spreads across the lane 50 until the lane 50 has a substantially constant thickness of the liquid sample 14 across the length of the lane 50.

[0029] 7, the sample preparation system 10 includes an electronic controller 138 configured to automatically or semi-automatically control the inkjet printer 30. The controller may include a programmable processor 142 (e.g., a microprocessor, microcontroller, or another suitable programmable device) and memory 146, such as non-transitory memory. The memory 146 may include, for example, a program storage area 150 and a data storage area 154. The program storage area 150 and the data storage area 154 may include a combination of different types of memory 146, such as read-only memory ("ROM"), random access memory ("RAM") (e.g., dynamic RAM ["DRAM"], synchronous DRAM ["SDRAM"], etc.), electrically erasable programmable read-only memory ("EEPROM"), flash memory, hard disk, SD card, or other suitable magnetic, optical, physical, electronic memory device, or other data structure. The programming may be coded or learned.

[0030] As an example, the electronic controller 138 may be configured to control the movement of the printer 18. For example, the electronic controller 138 may control the rotation of the printer 18. The electronic controller 138 may further be configured to control the position or linear translation of the printer 18 in three-dimensional space, including moving in the X-direction, the Y-direction, and / or the Z-direction in any combination or orientation, for example, to move the printer 18 to print droplets 26 in each lane 50. The electronic controller 138 may further be configured to communicate with the printer 18 when printing is appropriate (i.e., when the printer 18 is in the correct position over the lane 50). This may be done using the sensor 158 to detect the position of the printer 18 and the corresponding lane 50. The sensor may be an optical sensor, a proximity sensor, an accelerometer, any other sensor, or the like.

[0031] 8 is a flow chart illustrating a method of preparing a liquid sample 14 for analysis in a charged particle microscope (e.g., a transmission electron microscope, a scanning electron microscope, etc.). The method includes certain steps, although not all of the steps need to be performed or in the order presented. In some embodiments, the method may include additional steps. At least a portion of the method may be performed by the electronic controller 138.

[0032] In step 801, a user provides a grid 22. The grid 22 includes a first layer 42 on a front side 34 and a backing material 40 on a back side 38. In an embodiment of the method, the backing material 40 is a foil. The first layer 42 defines a plurality of lanes 50, and the backing material 40 supports the first layer 42. Each lane 50 includes a first end 98 and a second end 99. The first end 98 is configured to receive a liquid sample 14 in a later step (step 802). The second end 99 is opposite the first end 98. A length 100 extends from the first end 98 to the second end 99. The backing material 40 defines a bottom 110 of each lane 50. The lanes 50 have a height 134 and a width 130, with an aspect ratio of, for example, 20. Prior to this step, the first layer 42 and the grid 22 may be aligned by the user or by an alignment device (not shown), such as a micromanipulator.

[0033] In step 802, a droplet 26 of the liquid sample 14 is applied to each lane 50. The droplet 26 is inserted on the first layer 42 side. The droplet 26 is further inserted on the first end 98 of each of the plurality of lanes 50. Each droplet 26 may be the same liquid sample 14, or each droplet 26 may be a different liquid sample 14. In some embodiments, applying the droplet 26 includes printing the droplet 26 of the liquid sample 14 using an inkjet printer 30. The printer 30 may detect the position of each lane 50 using a sensor 158. In other embodiments or methods, the printer 18 may print the droplet 26 on each lane 50 on the backside 38. In still other embodiments, the droplet 26 may be applied by a pipette or other suitable tool. In response to the hydrophilicity and aspect ratio of the lane 50, each droplet 26 spontaneously spreads through each lane 50 via spontaneous capillary flow.

[0034] In step 803, the liquid sample 14 is vitrified. In some embodiments, the liquid sample 14 is vitrified by inserting the grid 22 into a bath of liquid ethane to complete the sample preparation process. The grid 22 may be inserted into the bath by a user, by a micromanipulator, or by a manipulation tool (e.g., tweezers, clamp, etc.). Alternatively, a jet of liquid ethane may be directed at the grid 22. In alternative embodiments, the liquid sample 14 may be inserted into a bath of a different liquid.

[0035] After the liquid sample has been prepared, a user may analyze the liquid sample using a charged particle microscope, such as a TEM.

[0036] The aspect ratio and hydrophilicity of the lane 50 provide advantages. If the lane 50 has an aspect ratio such that SCF does not occur, the liquid sample 14 may have a non-uniform thickness 122 or the lane 50 may not fill at all. The aspect ratio and hydrophilicity of the lane 50 ensure that SCF occurs and allow for a reproducible liquid sample thickness 122. This provides reproducibility of the sample thickness 122 during each sample preparation procedure. Evaporation of the liquid sample 14 may be used to determine the final thickness 122. Alternatively, filter paper may be used to blot and thin the liquid sample 14. The filter paper may be used to blot the entire lane 50 or may be used to blot only the inlet. The inkjet printer 18 provides an additional advantage. If a sample (such as the liquid sample 14) is inserted onto the grid 22 without the printer 18, sample loss may occur. The use of the inkjet printer 18 reduces sample loss by precisely printing small droplets 26 of the liquid sample 14 within each lane 50, a precision that cannot be easily reproduced by another tool (i.e., a pipette).

[0037] Various features and advantages of the invention are set forth in the following claims.

Claims

1. 1. A grid for sampling a liquid sample, said grid comprising: a first layer, the first layer including a plurality of lanes, each lane having a first end configured to receive a droplet of the liquid sample, a second end opposite the first end, and a length extending from the first end to the second end; a backing material supporting the first layer.

2. The grid of claim 1 , wherein the first layer is a mesh.

3. The grid of claim 2 , wherein the backing material defines a bottom of each lane.

4. The grid of claim 1 , wherein the first layer is a foil and the lanes are etched into the foil.

5. The grid of claim 1 , wherein the backing material is a foil.

6. The grid of claim 5 , wherein the foil includes a plurality of holes.

7. 2. The grid of claim 1, wherein the first layer defines a ridge relative to the backing material, the ridge defining a thickness of the liquid sample.

8. The grid of claim 1 , wherein the lanes extend generally parallel to one another.

9. The grid of claim 1 , wherein at least one of the plurality of lanes is linear.

10. The grid of claim 1 , wherein at least one of the lanes is curved.

11. The grid of claim 1 , wherein at least one of the plurality of lanes tapers from the first end to the second end.

12. The grid of claim 1 , wherein the first layer has a thickness of 10 to 15 micrometers.

13. The grid of claim 1 , wherein the backing material has a backing thickness of 10 to 15 nanometers.

14. 2. The grid of claim 1, wherein the liquid sample is a first liquid sample and the second end is configured to receive a second droplet of a second liquid sample.

15. 15. The grid of claim 14, wherein the second liquid sample is different from the first liquid sample.

16. A transmission electron microscope sample preparation system (TEM sample preparation system), comprising: A grid configured to sample a liquid sample, the grid including a first layer including a plurality of lanes, and a backing material supporting the first layer, each lane having a first end configured to receive the liquid sample, a second end opposite the first end, and a length extending from the first end to the second end, the backing material defining a bottom of each lane; an applicator configured to apply a droplet of the liquid sample onto each lane such that spontaneous capillary flow of the liquid sample occurs.

17. 17. The TEM sample preparation system of claim 16, wherein the volume of the droplet is substantially the same as the volume of the lane.

18. 17. The TEM sample preparation system of claim 16, wherein the first layer is a foil and the lanes are etched into the foil.

19. 17. The TEM sample preparation system of claim 16, wherein the first layer is a mesh.

20. 20. The TEM sample preparation system of claim 19, wherein the mesh defines a ridge relative to the backing material, the ridge defining a thickness of the liquid sample.

21. 17. The TEM sample preparation system of claim 16, wherein the multiple lanes extend generally parallel to one another.

22. 17. The TEM sample preparation system of claim 16, wherein the applicator applies droplets having a droplet size of 1 picoliter to 1 nanoliter.

23. 17. The TEM sample preparation system of claim 16, further comprising an electronic controller coupled to the applicator for controlling the applicator.

24. 17. The TEM sample preparation system of claim 16, wherein the applicator is an inkjet printer.

25. The TEM sample preparation system of claim 16 , wherein the applicator is a syringe.

26. 1. A method for preparing a liquid sample, the method comprising: providing a grid, the grid including a first layer including a plurality of lanes, and a backing material supporting the first layer, each lane having a first end configured to receive the liquid sample, a second end opposite the first end, and a length extending from the first end to the second end, the backing material defining a bottom of each lane; applying a droplet of the liquid sample onto the first end of each of the plurality of lanes such that the plurality of lanes are filled via spontaneous capillary flow.

27. 27. The method of claim 26, further comprising the step of vitrifying the liquid sample.

28. 27. The method of claim 26, wherein applying the droplets comprises printing the droplets of the liquid sample using an inkjet printer.

29. 27. The method of claim 26, further comprising controlling evaporation of the liquid sample.

30. 27. The method of claim 26, further comprising the step of blotting the liquid sample to control sample thickness.

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