Abstract:
The invention relates to a fluid reservoir, in particular a fluid reservoir to be integrated into a miniaturized flow cell, comprising a reservoir space, which is enclosed by two bodies ( 6,7 ) that lie against each other in a fluid-tight manner. According to the invention, in addition to a stored liquid ( 9 ), a solid filling body ( 12 ) that fills the remaining reservoir space is arranged in the reservoir space. A part of the reservoir space filled by the stored liquid is preferably bounded predominately by one of the two bodies ( 6,7 ) and the solid filling body ( 12 ).

Description:
The present application is a 371 of International application PCT/DE2010/000646, filed Jun. 7, 2010, which claims priority of DE 10 2009 032 744.4, filed Jul. 11, 2009, the priority of these applications is hereby claimed and these applications are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The invention relates to a fluid reservoir, particularly a fluid reservoir for integration in a miniaturized flow cell, with a reservoir space which is enclosed by two bodies which rest against each other in a fluid-tight manner. 
     The invention further relates to a method for manufacturing such a fluid reservoir. 
     Fluid reservoirs of this type are known, for example, as blister reservoirs which can be emptied by deformation. The dome-like reservoir space of such blister reservoirs always contains a certain quantity of residual air which impairs the precise metering of dispensed liquid volumes. The compressible residual air quantity initially ensures a delay of the liquid dispensation. When lowering a manual or mechanical contact pressure acting on the blister, an uncontrolled subsequent fluid discharge occurs because of the tension release of the air quantity. If it is attempted during the manufacture of the reservoir to prevent the injection of residual air by completely filling the reservoir space with the liquid, this results because of the curved liquid meniscus in an undesired displacement of liquid into a gap between the bodies which rest against each other. 
     SUMMARY OF THE INVENTION 
     The invention is based on the object of creating a novel fluid reservoir of the above-mentioned type which facilitates a more precise metering of dispensed liquid quantities. 
     The fluid reservoir according to the invention which meets this object is characterized in that, in addition to a stored liquid, a solid filling body which fills out the remaining reservoir space is arranged in the fluid reservoir. 
     For manufacturing such a fluid reservoir, an indentation is formed in the first body, the liquid to be stored is filled into the indentation, and the indentation is covered in a fluid-tight manner by a second body while forming the reservoir space, wherein in accordance with the invention, the indentation is only filled partially with the liquid and additionally a solid filling body is placed in the indentation, wherein the filling body completely fills out the reservoir space together with the introduced liquid. 
     Since liquid and filling bodies completely fill out or almost completely fill out the reservoir space, no residual air cushions can be formed in the reservoir space which would delay or uncontrollably extend the liquid dispensation. 
     Preferably a portion of the reservoir space filled out by the stored liquid is delimited entirely or predominantly by one of the two bodies and the solid filling body. This means that when the reservoir is manufactured, the surface of the liquid facing the first body is covered entirely or partially by that filling body against which the second body is placed when the reservoir space is closed. In this manner, no liquid meniscus or only a small liquid meniscus is present opposite the second body. Alternatively, a liquid meniscus facing the first body could be pulled so as to be smooth by means of the filling body lowered into the liquid. 
     Accordingly, when covering the indentation by means of the second body air inclusions in the reservoir space and an undesired displacement of the liquid into the gap between the bodies cannot occur. 
     Preferably, the two bodies enclosing the reservoir space are not only connected in a fluid-tight manner, possibly under pressure, but are also connected to each other, particularly by welding or/and gluing them together. 
     In accordance with a preferred embodiment of the invention, the two bodies rest against each other with plane surfaces and the filling body has a surface which is flush with these plane surfaces. When covering the above-mentioned indentation by means of the second body no air inclusion is caused between the two bodies. 
     At least one of the two bodies can be formed by a foil which can be deformed for emptying the reservoir and, for example, covers an indentation in a thicker plate which forms the reservoir space. 
     However, in a particularly preferred embodiment of the invention, the foil itself has a bulge forming the reservoir space, so that a reservoir in the form of a blister is created. In particular, two foils form the reservoir, wherein at least one of the foils is deformed. The foils consist, for example, of a synthetic material, aluminum or aluminum coated with synthetic material and are glued or welded together in a fluid-type manner. 
     In an embodiment of the invention, the filling body is connected to one of the two bodies, particularly integrally connected, wherein the filling body protrudes from one of the bodies into an indentation formed by the other body and forming the reservoir space. When the indentation is covered by the one body, the protruding filling body is placed in the indentation and displaces all air therefrom. 
     The volume of the reservoir space portion filled out by the liquid may be small in comparison to the total volume of the reservoir space, i.e., by varying the size of the filling body the liquid quantities that can be filled in can be varied with a given total volume of the reservoir space. 
     The filling body may have a surface adapted to a die for deforming the aforementioned bulge. In this manner, a die which presses the blister bulge together is centered and an undesired formation of wrinkles of the blister foil is prevented. 
     In accordance with a further development of the invention, the filling body can form a tool for producing an outlet opening which can be actuated by deforming the foil. For example, the filling body may comprise a mandrel or a slide which punches a foil or/and causes an intended breaking point to burst. 
     The filling body may be a body which melts at room temperature. For example, a piece of ice forming the filling then ensure that a stored aqueous liquid is diluted. 
     Moreover, the filling body may be provided for an alternating effect with the stored liquid, wherein, in addition to chemical reactions, for example, the pick-up of undesired components from the liquid, such as, for example, particles, oxygen or ions, would be possible. 
     In a further development of the invention, the filling body has a hydrophilic surface which advantageously facilitates a slight wetting using the stored liquid. 
     In accordance with a further development of the invention, the filling body can be constructed for receiving gas, wherein it advantageously removes small residual air quantities from the reservoir space. Alternatively, the liquid can be degassed prior to storage, so that it can take in residual air. 
     It is understood that the filling body may be composed of several parts. 
     In an especially preferred embodiment, the filling body fills a step-shaped attachment of the bulge. The bulge which is, for example, spherical then does not transmit any forces to the lower foot edge or bulge, when it is being deformed. The formation of an outlet opening by breaking an intended breaking point at the base edge is not impaired. 
     In accordance with a further preferred embodiment of the invention the filling body comprises gaps, breakthroughs and/or ducts having certain dimensions which are wetted by the liquid to be stored when the filling body is placed in the reservoir and the air is displaced therefrom. When pressing the reservoir, the liquid to be stored is conducted in a controlled manner by means of these contours to the fluidic outlet of the reservoir, such as, for example, a blister channel as known from the prior art. 
     In accordance with a further embodiment, the flow cell connected to the reservoir can be connected to an injection needle, and the fluid to be stored may be a medicament, wherein emptying of the reservoir for dispensing a medicament is suitable comparable to a syringe. For this purpose, the reservoir space preferably has an oblong shape. 
     In the following the invention will be explained further with the aid of embodiments and the enclosed drawings which refer to these embodiments. In the drawing: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  is a partial sectional illustration of a flow cell with an integrated reservoir according to the prior art, 
         FIG. 2  is a partial sectional illustration of a flow cell with a first embodiment of a reservoir according to the invention, 
         FIG. 3  shows a second embodiment of a reservoir according to the invention with a reservoir volume for liquids which is smaller than that of the reservoir of  FIG. 2 , 
         FIG. 4  shows a third embodiment of a reservoir according to the invention with a filling body arranged in a stepped attachment of a blister bulge, 
         FIG. 5  shows a fourth embodiment for a reservoir according to the invention with a filling body constructed as a slide, 
         FIG. 6  shows a fifth embodiment of a reservoir according to the invention with a filling body comprising a mandrel, 
         FIG. 7  shows a sixth embodiment of a reservoir according to the invention with a filling body adapted to a pressing die, 
         FIG. 8  is an illustration explaining the manufacture of a reservoir according to the invention, 
         FIGS. 9 and 10  show two additional embodiments of reservoirs according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A flow cell partially illustrated in  FIG. 1  and in the following figures includes a plastic plate  1  with cavities which are covered by a foil  2  connected to the plastic plate  1 . In  FIGS. 1 to 5  and in  FIG. 7  the cavities can be seen as a chamber  3  and a transport channel  4 ; in  FIG. 6 , only a transport channel  27  can be seen. 
     On a side of the plastic plate  1  facing away from the foil  2  a fluid reservoir each is arranged which comprises two flat foils  6  and  7  which are connected to each other. The foil  6 , in turn, is connected on its side facing away from the foil  7  to the plastic plate  1 . The foils  6 ,  7  can be connected to each other and the foil  6  can be connected to the plate  1  by welding or/and gluing and/or by means of a double-sided adhesive film, not shown. 
     In accordance with  FIG. 1 , the foil  7  has a spherically shaped bulge  8  which forms between the foils  6 ,  7  a reservoir space for receiving a liquid  9 . By pressing against the bulge  8  at  10 , an opening channel leading to the transport channel  4  can be broken open. 
     As can be seen in  FIG. 1 , a residual air cushion  11  is formed in the reservoir space. When pressing the bulge  8 , the residual air is compressed which, after the intended breaking forming the opening channel  10  has burst, leads to an uncontrolled discharge of liquid from the reservoir space. 
     In the embodiment of  FIG. 2  a plate-shaped solid filling body  12  is arranged in the reservoir space of a reservoir  5   a , which filling body  12 , together with a liquid  9   a  contained in the reservoir space, completely fills out the reservoir space. Liquid  9   a  can penetrate only into a narrow gap between the plate border area of the filling body  12  and the wall of the reservoir space. The shape of the edge of the filling body determines the position and size of the gap. A plate surface  13  of the filling body  12  facing the foil  6  is arranged flush with the contact surface  14  formed between the foils  6 ,  7 . In contrast to reservoir  5 , no residual air or hardly any residual air is present in the reservoir space of the reservoir  5   a.    
     In the same manner, the reservoir space of a reservoir  5   b  shown in  FIG. 3  does not contain any residual air. The reservoir  5   b  differs from the reservoir  5   a  in that a filling body  15  is significantly thicker than the plate-shaped filling body  12 . Correspondingly, a smaller volume of a liquid  9   b  is enclosed in the reservoir  5   b . As illustrated in  FIG. 3 , by varying the plate thickness and geometry, with a given size of the bulge, reservoir spaces of different sizes for liquids can be formed, wherein very small reservoir spaces with exactly measured volumes can also be produced. 
       FIG. 4  shows a reservoir  5   c  with a bulge  8   c  which includes a stepped attachment  16 . A portion of the reservoir space formed by the stepped attachment  16  is filled out by a plate-shaped filling body  17  whose thickness is between the thickness of the filling body  12  and the thickness of the filling body  15 . Because of the stepped attachment, a base point  18  of the bulge  8   c  is laterally offset relative to the base point  19  of a spherically shaped part of the bulge  8   c , so that a pressure acting on the spherically shaped part is transmitted to the base point  18  reduced by only a weakened extent. The bursting in an intended breaking point present at  18  is not impaired as a result by the pressure acting on the bulge  8   c.    
     A fluid reservoir  5   d , as shown in  FIG. 5 , includes a filling body  20  which is articulated at  21 . Therefore by exerting a compressive force against the bulge  8   d  according to arrow  22 , a displacement of a portion of the filling body  22  in accordance with arrow  23  takes place, wherein the filling body pushes open an intended breaking point at  24  for forming an outlet opening. 
       FIG. 6  shows a reservoir  5   e  with a filling body  25 . The filling body  25  comprises a mandrel  26  which, when a compressive force acts on the bulge  8   e  in accordance with arrow  22  ( FIG. 5 ), can be punched through the foil  6  while forming an outlet opening, so that the reservoir  5   e  is in communication with the above-mentioned transport channel  27 . 
     In the embodiments of  FIGS. 5 and 6 , the liquid contained in the reservoir space contacts the foil  6  only over a relatively small area  31  or  32  which is uncritical in relation to the liquid displacement. 
     A reservoir  5   f  shown in  FIG. 7  includes a filling body  28  which on its side facing away from the foil  6  is shaped in accordance with a pressure die  29  for exerting a compressive force against the bulge  8   f.    
     Reference will now be made to  FIG. 8  which explains as an example the manufacture of the reservoir  5   f  shown in  FIG. 7 . 
     In accordance with  FIG. 8   a , in a first step the bulge  8   f  is made in the foil  7 , in the case of a plastic foil, for example, by hot deep drawing, and in the case of an aluminum foil as it is typically used for blisters by cold deep drawing. Liquid  9   f  to be stored is filled into the vessel space formed by the bulge  8   f . The marking line  30  in  FIG. 8   b  indicates the resulting liquid level. 
     In the following step in accordance with  8   c , the filling body  28  is then placed in the bulge  8   f , wherein the surface  13   f  of the filling body  28  facing away from the liquid  9   f  is aligned flush with the surface  14   f  of the foil  7  or protrudes slightly beyond the latter. 
     In the last step according to  FIG. 8   d , the foil  7  is connected to the foil  6  so as to form a closed reservoir space, wherein the reservoir space is filled out by the liquid  9   f  and the filling body  28  without any residual air. 
       FIGS. 9 and 10  show reservoirs which are similar to the reservoir of  FIG. 4  with a stepped attachment  16   g  or  16   h . A filling body  17   g  arranged in the stepped attachment  16   g  has at the edge a slot  35 . When the reservoir is emptied, liquid is conveyed through this slot  35  to an outlet opening of the reservoir  24   g.    
     A filling body  17   h  of the reservoir of  FIG. 10  has a central passage and a radial channel  37  which leads to a reservoir outlet opening  24   h.