Dispensing liquids in quantities from picoliters to microliters is an essential operation in many areas of pharmaceutical and biology research, as well as in medical and veterinary diagnostics, forensics testing, and agricultural testing. Even within these fields, low-volume liquid dispensing is used for many different operations.
One stage of pharmaceutical research, during which low-volume liquid dispensing is important, is directed to determining the concentration of a compound needed to effectively attack or inhibit a target (e.g., a virus). These are generally called dose-response experiments. Many different concentrations of the compound are created in containers, such as wells of a well plate, to determine the effective concentration. Dispensing systems direct liquids into the wells.
In the drawings:
Use of the same reference numbers in different figures indicates similar or identical elements.
As used herein, the term “includes” means includes but not limited to, the term “including” means including but not limited to. The terms “a” and “an” are intended to denote at least one of a particular element.
Liquid dispenser cassette
A digital dispenser is an apparatus that utilizes dispense heads based on inkjet technology to accurately apportion picoliter to microliter doses of compounds into wells on a well plate. In operation, the digital dispenser is loaded with a cassette and a technician pipets samples into reservoirs on the cassette. Under software control, the digital dispenser dispenses predetermined amounts of the samples into the wells.
Researchers may mix an active compound with a liquid medium such as a solvent, a filler, or a carrier. An example of a solvent is dimethyl sulfoxide (DMSO). This liquid solution is placed into a dispense head on a cassette and digitally dispensed into wells of a well plate. In a research experiment, different amounts of the active compound mixed with the liquid medium may be dispensed into each of the wells. This causes the amount of the liquid medium in each well to be different. Thus a “normalization” step may be employed to equalize the amount of the liquid medium dispensed into each well. In this normalization step, a complimentary quantity of the liquid medium is added to each well of the experiment, such that the total quantity of the liquid medium in each experimental well is equal. An equal amount of the liquid medium in the wells allows the researchers to see only the effect of the active compound instead of the variation in the liquid medium. As experiments may be designed on a logarithmic scale, the amount of the liquid medium required to normalize a well plate may be quite large.
In examples of the present disclosure, a liquid dispenser cassette is provided to normalize wells. The cassette may have less than eight dispense heads and at least a one-piece integrated slot extender having multiple reservoirs for the dispense heads. By reducing the number of dispense heads, the volume of the reservoirs may be increased to handle normalization and the cost of the cassette may be reduced. By integrating multiple reservoirs into a single slot extender, they may be better aligned with the other components of the cassette.
Frame 902 defines openings 908-1, 908-2, 908-3, and 908-4 (hereafter collectively as “openings 908” and individually as a generic “opening 908”). Frame 902 includes top alignment features 910-1, 910-2, 910-3, and 910-4 (hereafter collectively as “top alignment features 910” and individually as a generic “top alignment feature 910”).
Dispense head assemblies 904-1, 904-2, 904-3, and 904-4 include respective dispense head dies 912-1, 912-2, 912-3, and 912-4 (hereafter collectively as “dispense head dies 912” and individually as a generic “dispense head die 912”) to dispense fluid. Dispense head assemblies 904 are mounted on frame 902 so dispense head dies 912-1, 912-2, 912-3, and 912-4 are at least partially exposed through corresponding openings 908-1, 908-2, 908-3, and 908-4. Dispense head dies 912-1, 912-2, 912-3, and 912-4 have respective top slots 914-1, 914-2, 914-3, and 914-4 (hereafter collectively as “top slots 914” and individually as a generic “top slot 914”). Dispense head dies 912 have nozzle arrays 802 (
Slot extender 906 includes reservoirs 916-1, 916-2, 916-3, and 916-4 (hereafter collectively as “reservoirs 916” and individually as a generic “reservoir 916”) to hold fluids for respective dispense heads 912-1, 912-2, 912-3, and 912-4. Reservoirs 916-1, 916-2, 916-3, and 916-4 define respective drain openings 918-1, 918-2, 918-3, and 918-4 (hereafter collectively as “drain openings 918” and individually as a generic “drain opening 918”). Reservoirs 916 also define respective bottom alignment features 1302 (only one is shown in
In one example, frame 902 defines a recess 920 for receiving dispense head assemblies 904. Openings 908 are made through recess 920, and top alignment features 910 are located in recess 920.
In one example, cassette 100 includes a preform of a pressure sensitive adhesive (PSA) 924 that is placed in recess 920 before dispense head assemblies 904. PSA 924 defines openings 926-1, 926-2, 926-3, and 926-4 (hereafter collectively as “openings 926” and individually as a generic “opening 926”) that align with corresponding openings 908-1, 908-2, 908-3, and 908-4. Openings 926 may be larger than openings 908. PSA 924 defines openings 928-1, 928-2, 928-3, and 928-4 (hereafter collectively as “openings 928” and individually as a generic “opening 928”) that align with corresponding top alignment features 910-1, 910-2, 910-3, and 910-4. Dispense head assemblies 904 and slot extender 906 are at least partially fixed by PSA 924. Adhesives may also be placed between drain openings 918 and top slots 914, and between alignment features 910 and 1402 (
Although illustrated with four dispense head assemblies 904, cassette 100 may accommodate one to seven or greater than eight dispense head assemblies 904. Although illustrated with a single one-piece integrated slot extender 906 with four reservoirs 916, cassette 100 may use two one-piece integrated slot extenders each with two reservoirs.
In one example, frame 902 is substantially rectangular in shape but for the inclusions of a handle 922 extending from one edge and alignment cutouts along other edges. In one example, handle 922 includes a rounded edge. In one example, recess 920 and dispense head assemblies 904 are substantially rectangular in shape, dispense head assemblies 904 are oriented with their longer dimension parallel to the shorter dimension of recess 920, and dispense head assemblies 904 are evenly spaced in the longer dimension of recess 920, for example according to the earlier mentioned pitch. Slot extender 906 is mounted on dispense head dies 912 and leaves electrical contact pads 1004 (
Reservoir
Liquid may be stranded in a reservoir of a dispense head after all dispensable fluid has been depleted. This may be undesirable as it increases the cost of the material.
In examples of the present disclosure, a reservoir is provided to minimize stranded fluid. The reservoir may have ribs connecting a sidewall to a drain hole of the reservoir. A fillet may be provided where the sidewall and the ribs join a reservoir floor. The fillet may have a continuous variable radius that starts with a large radius and tapers to a smaller radius near the drain opening to pull liquid toward the drain opening.
In one example, reservoir floor 1102 is a conical surface with a vertex centered about drain opening 918 and a vertical (plumb) axis so liquid would flow to drain opening 918 when reservoir 916 is placed on a horizontal (level) surface, such as when cassette 100 is placed in a digital dispenser.
Referring back to
In one example, reservoir 916 includes another rib 1112 extending from reservoir floor 1102 and running from the opposite reservoir sidewall section 1106-4 to drain opening 918. In this example, concave fillet 1108 further runs along where reservoir rib 1112 joins reservoir floor 1102.
Ribs 1110 and 1112 divide reservoir 916 into compartments 1114 and 1116. Compartment 1114 has concave fillet 1108 while compartment 1116 has a concave fillet 1118 with a continuous variable radius to pull liquid toward drain opening 918. Concave fillet 1118 runs along where reservoir sidewall 1104 and ribs 1110 and 1112 join reservoir floor 1102. Although two ribs 1110, 1112 are shown, reservoir 916 may include additional ribs that divide reservoir 916 into more than two compartments. For example, one additional rib may be introduced to divide reservoir 916 into three compartments, and two additional ribs may be introduced to divide reservoir 916 into four compartments.
In one example, concave fillet 1108 decreases in radius as it travels in opposite directions away from location 1202 of reservoir sidewall section 1106-3 toward drain opening 918 as shown in
In one example, ribs 1110 and 1112 are shorter than reservoir sidewall 1104 so liquid can fill over ribs 1110 and 1112 in order for reservoir 916 to store a greater volume of liquid.
In one example, compartments 1114 and 1116 are the same size or different sizes. In one example, drain opening 918 is symmetrical or asymmetrically distanced from opposing reservoir sidewall sections 1106-2 and 1106-4. In one example, reservoir 916 is connected to at least another reservoir 916 in a row.
Referring to
Frame 1502 defines a single opening 908 (not visible in
Reservoir 1504 defines a drain opening 918. Reservoir 1504 is mounted on dispense head assembly 904 so drain opening 918 mates to top slot 914. Like reservoir 916 (
Reservoir 916 (
Various other adaptations and combinations of features of the examples disclosed are within the scope of the invention.
This patent application is a continuation application of U.S. patent application Ser. No, 14/654,706, filed Jun. 22, 2015, titled “RESERVOIR WITH VARIABLE RADIUS FILLET,” which is a U.S. National Stage Application of and claims priority to International Patent Application No. PCT/US2013/020704, filed on Jan. 8, 2013, the contents of each of which are hereby incorporated by reference in their entirety.
Number | Name | Date | Kind |
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D655423 | Nielsen | Mar 2012 | S |
Number | Date | Country | |
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20170312750 A1 | Nov 2017 | US |
Number | Date | Country | |
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Parent | 14654706 | US | |
Child | 15650599 | US |