1. Technical Field
Embodiments are directed to microfluidic delivery systems that include fluid dispensing refill cartridges and methods of sealing the same.
2. Description of the Related Art
Fluid delivery systems that include refill cartridges are currently being used in the printer industry. Many printers, including 3D printers, use replaceable inkjet cartridges that incorporate an ink reservoir and a print head for delivering ink from the reservoir to the paper. The print head is usually located below the ink reservoir. Typically, the inkjet cartridges have nozzles for expelling the ink located below the ink reservoir and a vent hole on the top side of the ink reservoir for equalizing the pressure in the ink reservoir. Thus, the nozzles and vent hole are located on opposing surfaces of the inkjet cartridges.
Both the vent hole and the nozzles are preferably sealed when not in use to prevent leakage and evaporation of the ink. With the vent hole and the nozzles on opposing surfaces, a two-step process may be performed for sealing. For instance, a first step may be performed to seal the vent hole and a second step may be performed to seal the nozzles. Alternatively, a large cover that wraps around opposing surfaces and along a side surface of the cartridge may be used to seal the cartridge and the vent hole.
Embodiments disclosed herein are directed to a microfluidic refill cartridge having a vent hole and nozzles on a same side of the cartridge. In one or more embodiments, the vent hole and nozzles are located on upper surfaces of the cartridge, such as on a lid that is coupled to a reservoir. In particular, the nozzles and the vent hole may be formed on a microfluidic delivery member that is secured to the lid. Thus, a single cover may be used to cover the vent hole and the nozzles. In some embodiments, the single cover may be a flexible material and may adhere to the microfluidic delivery member.
The nozzles may be formed in a nozzle plate of a die that is secured to an upper surface of microfluidic delivery member, while the vent hole may be formed in a surface of the microfluidic delivery member. In some embodiments, the nozzle plate has an upper surface that lies in a different plane from the upper surface of the microfluidic delivery member. Thus, the cover may include a flexible material that conforms to the upper surface of the nozzle plate and the upper surface of the microfluidic delivery member. In one embodiment, the cover includes an inner flexible portion that is located above the nozzles and the vent hole and an outer hard portion. It is to be appreciated that a single processing step may be used to seal the nozzles and the vent hole. In addition, the nozzles and vent hole may be located close together so that the cover may be small and use a small amount of material.
In the drawings, identical reference numbers identify similar elements. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale.
Access to the interior portion 22 of the housing is provided by an opening 28 in the body portion 18 of the housing 12. The opening 28 is accessible by a cover or door 30 of the housing 12. In the illustrated embodiment, the door 30 rotates to provide access to the opening 28. Although the opening and door are located on the body portion of the housing, it is to be appreciated that the opening and door may also be located on the upper surface and the lower surface of the housing. Furthermore, it is to be appreciated that in other embodiments, the housing has two or more separable parts for providing access to the interior portion.
The holder member 24 includes an upper surface 32 and a lower surface 34 that are coupled together by one or more sidewalls 36 and has an open side 38 through which the microfluidic refill cartridge 26 can slide in and out. The upper surface 32 of the holder member includes an opening 40 that is aligned with the first hole 20 of the housing 12.
The holder member 24 holds the microfluidic refill cartridge 26 in position when located therein. In one embodiment, the holder member 24 elastically deforms, thereby gripping the microfluidic refill cartridge 26 in place when located in the holder member. In another embodiment, the holder member 24 includes a locking system (not shown) for holding the microfluidic refill cartridge in place. In one embodiment, the locking system includes a rotatable bar that extends across the open side of the holder member to hold the microfluidic refill cartridge in place.
The housing 12 includes conductive elements (not shown) that couple electrical components throughout the system as is well known in the art. The housing 12 may further include connection elements for coupling to an external or internal power source. The connection elements may be a plug configured to be plugged into an electrical outlet or battery terminals. The housing 12 may include a power switch 42 on a front of the housing 12.
A lid 54, having an inner surface 56 and an outer surface 58, is secured to an upper portion 60 of the reservoir 50 to cover the reservoir 50. The lid 54 may be secured to the reservoir in a variety of ways known in the art. In some embodiments, the lid 54 is releasably secured to the reservoir 50. For instance, the lid 54 and the upper portion 60 of the reservoir 50 may have corresponding threads, or the lid 54 may snap onto the upper portion 60 of the reservoir 54. Between the lid 54 and the reservoir 50 there may be an O-ring 62 for forming a seal therebetween. The seal may prevent fluid from flowing therethrough as well as prevent evaporation of the fluid to an external environment.
A microfluidic delivery member 64 is secured to an upper surface 66 of the lid 54 of the microfluidic refill cartridge 26 as is best shown in
In reference to
As best shown in
Above the chamber 88 is a first through hole 90 in the lid 54 that fluidically couples the chamber 88 above the second end 84 of the fluid transport member 80 to a second through hole 78 of the microfluidic delivery member 64. The microfluidic delivery member 64 is secured to the lid 54 above the first through hole 90 of the lid 54 and receives fluid therefrom.
In some embodiments, the fluid transport member 80 includes a polymer; non-limiting examples include polyethylene (PE), including ultra-high molecular weight polyethylene (UHMW), polyethylene terephthalate (PET), polypropylene (PP), nylon 6 (N6), polyester fibers, ethyl vinyl acetate, polyvinylidene fluoride (PVDF), and polyethersulfone (PES), polytetrafluroethylene (PTFE). The fluid transport member 80 may be in the form of woven fibers or sintered beads. It is also to be appreciated that the fluid transport member of the present disclosure may be smaller than reservoir. This is distinct from cartridges that include foam which fills the reservoir.
As shown in
The outer sleeve 85 may be a material that is wrapped around the fluid transport member 80. In other embodiments, the material 85 is formed on the fluid transport member 80 in an initial liquid state that dries or sets on the fluid transport member. For instance, the material may be sprayed on the fluid transport member or the fluid transport member may be dipped into a liquid material that dries. The outer sleeve may be a polymer sheet, a Teflon tape, a thin plastic layer, or the like. Teflon tape has particular benefits since it provides a fluid-tight seal, is flexible to wrap, is strong, and also makes it easy to slip member 80 into place.
The fluid transport member 80 may be any shape that is able to deliver fluid 52 from the reservoir 50 to the microfluidic delivery member 64. Although the fluid transport member 80 of the illustrated embodiment has a width dimension, such as diameter, that is significantly smaller than the reservoir, it is to be appreciated that the diameter of the fluid transport member 80 may be larger and in one embodiment substantially fills the reservoir 50.
The upper surface 68 of the second end 76 of the printed circuit board 106 includes a semiconductor die 92 above the second through hole 78 and leads 112 located proximate the die 92. Electrical contacts 74 at the first end 72 of the microfluidic delivery member 64 are coupled to one or more of the leads 112 at the second end 76 by electrical traces (not shown).
The upper and lower surfaces 68, 70 of the PCB 106 may be covered with a solder mask 124 as shown in the cross-section view of
The die 92 is secured to the upper surface 68 of the printed circuit board 106 by any adhesive material 104 configured to hold the semiconductor die to the PCB. The adhesive material may be an adhesive material that does not readily dissolve by the fluid in the reservoir. In some embodiments, the adhesive material is activated by heat or UV. In some embodiments, a mechanical support (not shown) may be provided between a bottom surface 108 of the die 92 and the upper surface 68 of the printed circuit board 106.
As best shown in
As best shown in
As is best shown in
Each nozzle 130 is in fluid communication with the fluid in the reservoir by a fluid path that includes the first end 82 of the fluid transport member 80, through the transport member to the second end 84, the chamber 88 above the second end 84 of the transport member, the first through hole 90 of the lid, the second through hole 78 of the PCB, through the inlet path 94 of the die, through the channel 126, to the chamber 128, and out of the nozzle 130 of the die 92. In reference again to
The filter 96 may be any material that blocks particles from flowing therethrough and does not break apart when exposed to the fluid, which could create further particles to block the fluid path. In one embodiment, the filter 96 is a stainless steel mesh. In other embodiments, the filter 96 is a randomly weaved mesh and may comprise polypropylene or silicon.
It is to be appreciated that in some embodiments, the fluid transport member 80 is made from one or more materials that do not react with the fluid. Thus, the fluid transport member 80 does not introduce contaminants into the fluid that could block fluid flow through the microfluidic delivery member 64. In one embodiment, the fluid transport member may replace the filter.
The second through hole 78 of the microfluidic delivery member 80 may include a liner 100 that covers exposed sidewalls 102 of the PCB 106. The liner 100 may be any material configured to protect the PCB from breaking apart, such as to prevent fibers of the PCB from separating. In that regard, the liner 100 may protect against particles from the PCB 106 entering into the fluid path and blocking the nozzles 130. For instance, the second through hole 78 may be lined with a material that is less reactive to the fluid in the reservoir than the material of the PCB. In that regard, the PCB may be protected as the fluid passes therethrough. In one embodiment, the through hole is coated with a metal material, such as gold.
Prior to use, the microfluidic refill cartridge 26 may be primed to remove air from the fluid path. During priming, air in the fluid path is replaced with fluid from the reservoir 50. In particular, fluid may be pulled up from the fluid transport member 80 to fill the chamber 88, the first through hole 90 of the lid 54, the second through hole 78 of the microfluidic delivery member 64, the inlet path 94 of the die 92, the channel 126, and the chamber 128. Priming may be performed by applying a vacuum force through the nozzles 130. The vacuum force is typically performed with the microfluidic refill cartridge in an upright position for a few seconds. In some embodiments, a vacuum force is applied for 30 to 60 seconds. The microfluidic refill cartridge 26 may also be primed by applying air pressure through a hole 140 (
Once primed, during use, when fluid exits the nozzle 130, fluid from the reservoir 50 is pulled up through the fluid path by capillary action. In that regard, as fluid exits the chamber 128, fluid automatically refills the chamber 128 by being pulled through the fluid path by capillary action.
As indicated above, the transport cover 86 in combination with the second end 84 of the fluid transport member 80 form a seal that fluidly isolates the chamber 88 from the reservoir 50 to assist in keeping the microfluidic refill cartridge 26 primed. It is to be appreciated that the chamber 88 may be at a different pressure than the reservoir 50.
It is to be appreciated that in many embodiments, the fluid transport member 80 is configured to self-prime. That is, fluid may travel from the first end 82 of the fluid transport member 80 to the second end 84 without the aid of a vacuum force or air pressure as discussed above.
The microfluidic refill cartridge 26 includes a vent path that places the reservoir in fluid communication with the external environment of the microfluidic refill cartridge 26. During use, the vent path equalizes the air pressure in the reservoir 50 with the air pressure of the external environment. That is, as fluid exits the microfluidic refill cartridge 26 through the nozzles 130, air from the external environment fills the space in the reservoir 50 that is made by the removed fluid. In that regard, the air pressure in the reservoir 50 above the fluid remains at atmosphere. This allows the microfluidic refill cartridge 26 to remain primed and prevents or at least reduces back pressure in the fluid path. That is, by equalizing the pressure in the reservoir 50, the reservoir 50 does not create a vacuum that pulls the fluid from the fluid path back into the reservoir 50.
Referring now to
Once primed, the nozzles 130 may be sealed to prevent de-priming of the fluid path. De-priming may occur when air enters the fluid path, such as through the nozzles 130. Additionally, the second vent hole 144 in the microfluidic delivery member 64 may also be sealed to prevent leakage and/or evaporation of the fluid 52 in the reservoir 50.
Returning to
In some embodiments, the cover 150 is configured to conform to the topography of the microfluidic delivery member 64 to assist in sealing the nozzles 130 and the second vent hole 144. That is, the nozzle plate 132 that includes the nozzles 130 is in a first plane and the second vent hole 144 of the microfluidic delivery member 64 is in a second plane that is different from the first plane. The first and second planes, however, are very close together and thus are substantially co-planar. In one embodiment, the die is about 450 microns thick. Thus, with adhesive material between the die 92 and the microfluidic delivery member 64 the first and second planes may be approximately 500 microns apart. Additionally, in some embodiments, a support structure may be located between the die 92 and the microfluidic delivery member 64 making the first and second planes 800 microns or more apart. The cover 150 may be configured to conform to the first and second planes of the microfluidic delivery member 64. In that regard, at least a portion of the cover 150 may be a flexible material.
In
It is preferred that the adhesive material on the tape does not get into the nozzles 130 and vent hole 144 and block them after the tape is removed. That is, adhesive material that remained on the microfluidic delivery member 64 could affect the operation the microfluidic refill cartridge 26. Thus in some embodiments, the tape may have adhesive material around its perimeter and not in the center. In such embodiments, the tape may cover a larger area of the microfluidic delivery member 64 and/or may cover and adhere to the outer surface 58 of the lid 54.
Alternatively, a member (not shown) may be placed between the tape and both the second vent hole 144 and the nozzles 130. In that regard, although the entire under surface of the tape may have adhesive material, the adhesive material is prevented from touching the second vent hole 144 and the nozzles 130 while at the same time adhering the tape to the microfluidic delivery member 64, thereby sealing the nozzles 130 and second vent hole 144 from atmosphere.
Prior to placing the tape over the microfluidic delivery member 64 or the lid 54, the surfaces to which the tape will adhere may be cleaned. This will improve adherence properties between the adhesive material and the corresponding surface, such as the upper surface 66 of the microfluidic delivery member 64.
A cover 150a according to another embodiment is shown in
The cover 150a includes an outer cover 160 and an inner member 162 as shown in
The inner member 162 is made of a flexible material, such as a compressible material, and is located over the nozzles 130 and the second vent hole 144 and may cover the entire microfluidic delivery member 64. The inner member 162 may be foam that compresses when the outer cover 160 is secured to the lid 54 to form the seal. In one embodiment, the inner member 162 includes a strip of ethylene propylene diene monomer (EPDM) rubber proximate the second vent hole 144 and the nozzles 130. When the outer cover 160 is secured to the lid 54, the inner member 162 may compress slightly to seal the nozzles 130 and the second vent hole 144. The inner member 162 may be coupled to the outer cover 160 or may be a separate structure from the outer cover 160. For instance, the inner member 162 may be secured to an inner surface 166 of the outer cover 160 or may be molded to adhere to the inner surface 166 of the outer cover 160. In that regard, the inner member 162 and the outer cover 160 form a single cover that is coupled to the lid 54 of the microfluidic refill cartridge 26 in one step.
Alternatively, the inner member 162 may be placed over a portion of or all of the microfluidic delivery member 64 as a separate piece from the outer cover 160. The outer cover 160 may then be secured to the lid 54 by the clips 156 to hold the inner member 162 in place.
Having both the second vent hole 144 and nozzles 130 on the same side of the cartridge reduces processing steps and costs for sealing the microfluidic refill cartridge.
Upon removal of the cover, the microfluidic refill cartridge 26 may be placed into the holder member of the housing. Upon depletion of the fluid in the reservoir 50, the microfluidic refill cartridge 26 may be removed from the housing 10 and replaced with another microfluidic refill cartridge 26. Alternatively, the microfluidic refill cartridge 26 may be refilled through the hole 140 in the lid 54 as best shown in
The various embodiments described above can be combined to provide further embodiments. All of the U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet are incorporated herein by reference, in their entirety. Aspects of the embodiments can be modified, if necessary to employ concepts of the various patents, applications and publications to provide yet further embodiments.
These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure.
Number | Name | Date | Kind |
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5850238 | Karita et al. | Dec 1998 | A |
6033063 | Tomikawa et al. | Mar 2000 | A |
7188936 | Usui et al. | Mar 2007 | B2 |