DE202005019456U1 - Opto-fluidic plug-type connector used for a flow cell in liquid chromatography comprises a T-connecting piece joined to a glass fiber in a fluid-tight manner - Google Patents

Abstract

Opto-fluidic plug-type connector comprises a T-connecting piece joined to a glass fiber in a fluid-tight manner.

Description

The The invention relates to an opto-fluidic connector.

STATE OF TECHNOLOGY

The liquid chromatography (DE196 16 824 C2) works with highly aggressive solvents, therefore commonly used materials are stainless steel, quartz glass, ceramics, PTFE (Teflon) and PEEK ( DE 196 16 824 C2 ; 11, 5-25, DE 102 07 240 A1 ; 4, 24-28).

Especially in optical analysis methods quartz capillary tubes are often used. These have a small inner diameter (typically 100-2000 μm ( DE 196 16 824 C2 ; 8, 50-51) and, for optical reasons, a small jacket thickness and require high accuracy in the positioning of the optical elements.

Other analyzers that could make similar demands are: capillary electrophoresis ( DE 39 39 858 A1 ), NMR spectroscopy ( DE 41 01 473 C2 ) or in gas chromatography ( DE 694 30 342 T2 ).

Plug connections for optical fibers are known (eg CE 31 12 000 C2 ; DE 42 03 966 A1 ; Spinner fiber connector).

TASK

task In the invention, it is an improved flow cell, in particular to provide an improved optofluidic connector. The task is done by the independent claims solved. Further embodiments arise from the rest Dependent claims.

Corresponding embodiments the present invention

advantageously, can long thin quartz glass tubes be used, wherein the quartz glass tubes are traversed by a fluid can.

In addition, everyone can wetted by the fluid compounds have a high adhesive strength, such that, for example, it may reach a high pressure e.g. greater than 300 bar, possess their advantageous sealing properties.

Furthermore can the quartz glass tubes held in a narrow area around the tube ends be, for example in a range of less than 1 mm.

each Quartz glass tube can be illuminated by a pair of glass fibers. It can immerse the glass fibers in the quartz glass tubes so far the glass fiber ends are located behind the holding area of the quartz glass tubes.

Further can the positioning of the glass fibers to each other and to the glass tube executed very precisely be, for example in a tolerance range smaller than 10 microns.

advantageously, can, especially when using chemically aggressive fluids, highly resistant plastics such as PEEK and / or Teflon be used.

Of the Minimum distance between the parallel glass tubes can be smaller 4mm, whereby the optical requirements to be met by flow cells are met can.

advantageously, may be the flow cell, especially as a small diameter flow cell and greater Length executed in a big one Temperature range are operated e.g. from -40 ° C to +80 ° C.

It also gives a very small dead volume, in particular by avoiding and / or the reduction to a minimum of undercuts and poorly-perfused areas. Thereby allows the structure of the flow cell easy assembly, which in particular the flow cell can be mounted easily and inexpensively.

Finally, can the overall structure of the flow cell have a very flat construction.

embodiments The invention relates to the production of components with a guide structure for one Flow cell in which PEEK melted glass components to each other can be positioned passively. For the Producing the flow cell, a component is needed in a glass fiber is melted and a component in the the fluid leading Glass tube is integrated.

For the production of the nucleus (component with fluid guiding glass tube) become the following Parts needed: a quartz glass tube (fluid conducting tube); a jacket tube made of glass (or material with similar low thermal Expansion coefficient) whose inner diameter is larger as the outer diameter the fluid tube is; two preformed PEEK discs, with an inner hole, which is a bit bigger as the outer diameter of the fluid tube and having an outer diameter, which is slightly smaller than that of the jacket tube; a suitable forming device.

The Fluid pipe is inserted into the jacket pipe, one each PEEK disks will over pushed the ends of the fluid tube and the whole is in the forming device introduced. In the forming device is a contour that later for the passive Positioning of the plug is used. Furthermore, in the Forming device Structures exist that require a positioning of the fluid tube the connector contour during the forming phase allows. This structure may be formed by a pin immersed in the tube, a hole into which the fluid tube is inserted or through a conical depression take place, in which the fluid pipe by the flow movement the PEEK's at Forming process adapts. The forming device consists of a movable Component that compresses in the axial direction (alignment of the tube). The connector contour presses against the outer surfaces of the PEEK discs. moreover this device still has on both sides an opening which flows through the Fluid tube with e.g. hot Air allows.

are all components are inserted into the forming device, this is moved together and heated to a temperature of about 340 ° C. Is this Reached temperature, the forming device is continued to move together as long as until the sudden increase in forming force the mold filling the Plug contour and the Anformung to the fluid pipe signals. Both PEEK discs are backside pressed against the casing. Subsequently, through the fluid tube e.g. name is Passed air until the PEEK on the fluid pipe to a temperature from about 400 ° C heated and then the nucleus is removed. The parameters should be set that the heating of the fluid tube no strong heating of the Forming device is done, otherwise the PEEK also on the forming device strongly attached.

Of the thus manufactured nucleus consists now of a fluid tube, at whose Ends two PEEK disks are melted. Located in these PEEK disks outside a plug contour positioned to the fluid tube. The fluid tube itself is protective in the jacket tube locked in. Because of the similar Expansion coefficient of jacket and fluid pipe leads the high temperature difference (forming temperature and room temperature) to no burden of this arrangement. The PEEK discs are with not connected to the jacket tube in this way. If necessary can she, since she later have no contact with the fluid, additionally fixed with adhesive become.

The Production of the second connector components is done with glass fibers to similar ones Way. requires To this end, a glass fiber and a PEEK-molded part (T-piece) are used. The discoid Tee has in the center of the disc a through hole from the side a hole for the latter fluid supply is provided. The inside hole diameter is from the outside something bigger than the glass fiber diameter up to the lateral fluid supply of there to the inside, which later with a connector contour is provided, the hole diameter is then slightly larger than that Fluid tube diameter. In this tee now the glass fiber is inserted and inserted in a suitable forming device. In the forming device There are two guide holes whose aid the glass fiber is positioned to the forming tool. additionally lies on the inside of the tee a connector contour, which is formed in the forming step. The transformation takes place as in the nucleus. Is the forming force not too high, the shape of the fluid supply is maintained while the Fiberglass from the PEEK in the back of the tee forms on the glass fiber and the connector contour on the front maps. Subsequently This plug-in component is removed from the forming device. The glass fiber can then at the rear end of the plug-in component to a temperature of about 400 ° c are heated that it leads to a mechanically solid melting of the PEEK to the glass fiber comes. However, this step is not mandatory because the Glass fiber from the outside can be mechanically fixed with adhesive. An additional stability This plug-in component is made by bonding the glass fiber with a glass tube the size of which before corresponds described glass jacket tube and pushed back over the glass fiber and positioned in a suitable device to the glass fiber becomes.

The The flow cell then forms from the cell nucleus and two fiber optic connectors. These three components are thus introduced into a device by means of the jacket tubes nucleus and fiber optic connectors adjusted to each other and a non-contact Insertion of the glass fibers allowed in the fluid tube. The exact Positioning is then over the plug contours on cell nucleus and fiber optic connectors.

The fluidic seal in the contact area of the plug is done either by a permanent mechanical compression (the seal can hereby by inserting thinner Teflon film can be improved) or by a permanent connection, for example by means of a resistance welding process.

Advantageously, any kind of leakage can be avoided by the connector. On the one hand, connections can be absolutely pressure-tight and resistant to strong solvents. At the same time, the connectors can guarantee a high positional accuracy. It is Thus, it is possible to position an optical waveguide in a pressure-tight manner exactly in a fluid path designed for guiding highly agile liquids.

A Production of high-precision Metal parts is not necessary because of the necessary tolerance accuracy can be generated by means of a forming device. So it is only in the forming on an exact compliance of To respect tolerances. The generated with the help of the forming device Parts, so correspond to the high manufacturing accuracy of the forming device. Due to the simple plug connection, a complete system can Flow cell are very easy to set up, so in a few steps, which increases the overall error probability reduced system.

Advantageous is also that the materials used in their thermal Expansion coefficient only slightly different from each other, whereby thermal stresses due to temperature changes, for example, already During production and / or operation of the flow cell, to a minimum can be reduced.

Further embodiments relate to a forming device for positioning the glass parts, wherein the forming device at the same time the guides of the glass parts as well contains a connector contour. In a forming step can the glass parts positioned relative to the connector contours. The required high precision let yourself in spite of the shrinkage of the plastic after forming reach, since the shrinkage of both connector contours due to the similar manufacturing process and the like Dimensions corresponds. In addition, at least in the forming device at the same time a highly resilient connection of glass at the nucleus and PEEK achieved. By combining the forming and the joining step within the same device manufacturing can be simplified and the precision be improved.

Of the Nuclear core whose jacket tube surrounds the fluid tube and the connector contours plastic supports in the axial direction, has smaller dimensions, since a mechanical tensioning device is eliminated.

advantageously, can be a non-contact self-centering take place, in which a centering of the glass tube by the flow of material of the plastic is achieved.

By the similar ones thermal properties, the thermomechanical stability becomes clear improved.

Of the Cell is core and the fiber optic connectors can be manufactured as a single component become. this makes possible a quality control of the components after the critical manufacturing step of positioning and compound rather than a control of the overall assembly. Of the last assembly step is through the use of the jacket pipes as guides for one Prepositioning easier, also can be sensitive Easy handling of fluid tubes in the cell nucleus during assembly.

The Manufacture of the connector components is done by preformed PEEK parts with conventional Injection molding technology can be manufactured with sufficient accuracy, which the cost of semifinished products decreases.

Farther is the holder of the glass parts in plastic gentler than a guide in a metal device, especially if a two-stage sealing process for capillary tubes is applied.

By the use of jacket pipes will better protect the components and facilitate handling and assembly. In combination with a suitable base plate in which are guides for the jacket pipes, can the overall assembly of the system, especially the immersion the optical waveguide are facilitated in the fluid pipe. A largely planar construction is possible.

The Production concept is extremely flexible. The Measuring tube lengths and also the number of measuring tubes AND THEIR SPATIAL ARRANGEMENT TOGETHER can be easily varied without major procedural changes necessary are. For example, Can be used here to planar displaceable or circular Constructions that can be durchrotiert can be thought.

Embodiment

Other Tasks as well as many of the associated ones Advantages of embodiments The present invention will be readily understood with reference to the following detailed Description of exemplary embodiments and the accompanying drawing. Essentially the same, similar and / or functionally identical parts are provided with the same reference numerals. Show it:

1 shows a three-dimensional representation of a cell nucleus for a flow cell,

2 shows a three-dimensional representation of the in 1 represented nucleus, but in an exploded view,

3 shows a three-dimensional representation of a mounting device for welding the cell nucleus of the flow cell,

4 shows the mounting device 3 , but in exploded view,

5 shows a three-dimensional side view of a fiber holder for a glass fiber,

6 shows a three-dimensional plan view of a base plate for the construction of a flow cell,

7 shows a three-dimensional line view of a connection tee for building a flow cell,

8th shows a three-dimensional side front view of the flow cell 1 .

9 shows a three-dimensional view of a fiber connector,

10 shows a three-dimensional view of the fiber connector 9 together with the nucleus, wherein the nucleus and the fiber connector are partly put together,

11 shows a three-dimensional view of a mold together with the nucleus,

12 shows a three-dimensional view of two mold tools together with the fiber plug,

13 shows a three-dimensional side view of a mounting device for a flow cell,

14 and 15 show various three-dimensional views of PEEK disks after heat deformation,

16 shows a three-dimensional line representation of a tee for a fiber connection,

17 shows a PEEK perforated disc fluidly contacted with a steel cannula,

The eighteen and 19 show various views of the cannula together with a heatable wire loop,

20 shows another embodiment of a cell nucleus of a flow cell,

21 shows a side view of a PEEK disc,

22 shows a plan view of in 21 shown PEEK disc,

23 shows a three-dimensional front side view of a stamping mold,

24 shows a three-dimensional side rear view of the in 23 shown stamping mold, wherein an internal thread is visible to a guide pin,

25 shows a side view of the embossing mold together with the screw-in guide pin,

26 shows a mounting form designed to accommodate the in the 23 to 25 shown embossing forms,

27 shows a side view of in 26 shown mounting form,

28 shows a front view of the in 26 and 27 shown mounting form,

29 shows a further three-dimensional representation of a T-connector,

30 shows a side view of the in the 29 and 30 shown T-connector,

31 shows a front view of the in the 29 and 30 shown T-connector,

32 shows a three-dimensional representation of a stamping die applied for forming the front part of the T-connector,

33 shows a second mold designed to form the rear part of the T-connector,

34 shows the T-connector in a three-dimensional side front view together with the second mold,

35 shows a side view of the mounting form,

36 shows a further front view of the mounting form,

37 shows a side view of a punch for the cell nucleus of the flow cell,

38 shows a front view of the in 37 illustrated stamp,

39 shows a side view of a fixing plate for the guide pin,

40 shows a front view of the fixing plate off 39 .

41 shows a side view of a stamping mold for the cell nucleus,

42 shows a front view of the stamping mold 41 .

43 shows a side view of the PEEK disk for the nucleus,

44 shows a front view of in 43 shown PEEK disc,

45 shows a side view of the guide pin for the nucleus,

46 shows a front view of the in 45 shown guide pin,

47 shows a side view of a stamping mold designed for molding the front side of the fiber connector,

48 shows a front view of in 47 illustrated stamping mold,

49 shows a stamping mold designed to form the back of the fiber connector,

50 shows a front view of the in 49 represented fiber connector,

51 shows a side view of the T-connector of the fiber connector,

52 shows a front view of the in 51 shown T-connector,

53 shows a guide pin with an external thread,

54 shows a front view of the in 53 illustrated guide pin,

55 shows a hollow guide pin 55 which also has an external thread, and

56 shows a front view of the in 55 shown fiber connector.

THE manufacturing concept requires 5 steps:

1st step: production of the nucleus

The Fluid pipe is placed in a jacket tube made of glass, which is between two PEEK perforated discs are inserted, inserted and welded to the PEEK discs. at this welding step There is no connection of the jacket tube with the glass tube.

2nd step: production the fiber holder

The Glass fibers are also melted down in PEEK perforated discs. Subsequently, these can Glass fibers to the desired Length shortened and to be polished.

3rd step: adjustment and fixation of the fluid tube in the cell nucleus (the glass fibers).

There There is no connection of the PEEK discs to the jacket tube, both can Ends of the fluid tube in the plane parallel to the PEEK discs be moved. Is the desired Position reached, the PEEK discs with the jacket tube through Adhesive fixed. (The glass fibers attached in the PEEK disks are also adjusted in a jacket tube and glued.)

4th step: assembly the flow cell

The sheathed components of the flow cell are on any mark on the lateral surface adjusted. Therefore, both a passive and an active adjustment possible during installation. So can a high-precision management structure on the jacket tube allow a positioned telescoping. However, the jacket tube can also simplify the coarse adjustment Management structure serving, which ensures that the glass fibers dive along a guide in the fluid tube and then a fine adjustment by maximizing the optical signal through the glass fibers. For this, the mounting form has a lateral Allow shifting of the sheathed fiberglass components. T-pieces also become between glass fiber and fluid pipes PEEK used by the fluidic contacting takes place.

5th step: fixation the components and fluid connections

are the components adjusted to each other, these are fixed. This Can be reversible by a permanent compression of the components respectively. The pressing force must be achieved by an outer holding structure respectively. The fixation can also be irreversible by the PEEK components are welded by previously inserted heating structures. Also in this case must be during welding a high pressing force acting on the compounds. In a reversible Alternatively, the adjustment can also be done after compression the components take place. For the fixation of the fluid connections are also both a reversible connection (Schaubfitting) or an irreversible connection (resistance welding) possible.

Manufacturing concept flow cell

1 shows a three-dimensional representation of a flow cell 1 with a nucleus 2 , The nucleus 2 the flow cell 1 has a jacket tube 3 , a fluid pipe 5 and two PEEK perforated discs 7 on. 2 shows the nucleus 2 out 1 , but in an exploded view. It can be seen that in the fluid tube 5 as well as in the jacket tube 3 as well as in the perforated disc 7 each a centric bore 8th is introduced. The following will focus on the production of the nucleus 3 received.

1st step: production of the nucleus

The Temperature problem can only be solved if a fixation of the quartz glass tubes takes place in a holder with similar ones thermal expansion coefficient. Ceramics are conceivable, optimal would be quartz glass. The construction of a complex mount of such materials is probably very expensive. The most cost-effective variant and thermal optimal solution is therefore the use of larger quartz glass tubes, which encase the actual measuring tubes. Such quartz glass tubes are available in a variety of dimensions by the meter.

To construct a cell, the measuring tubes are welded into a jacket tube. For this purpose, a welding device or mounting device 9 be used.

3 shows a three-dimensional view of a mounting device 9 for welding the cell nucleus 2 the flow cell 1 .

4 shows the mounting device 9 as in 3 , but in exploded view.

In the mounting device 9 can the jacket pipe 3 together with the fluid pipe 5 inserted, or between two assembly blocks 11 be clamped. For clamping serve corresponding threaded rods 13 that with spacers 15 work together so that an exact positioning of the jacket tube 3 between the assembly blocks 11 results. The mounting blocks 11 point for the spacers 15 appropriate guides 17 on, for example, as stepped holes in the mounting blocks 11 can be executed. For pressing or attaching the PEEK perforated disc 7 has the mounting device 9 corresponding stamp 19 on, which has an external thread 21 exhibit. stamp 19 So can in a corresponding hole of the mounting device 9 or the mounting blocks 11 be screwed in so that the PEEK perforated discs 7 with the right pressure and the required positional accuracy with the jacket tube 3 and the fluid tube 5 to the nucleus 2 can be connected. The following is closer to the operation of the mounting device 9 or welding device received.

• – Auf das Mantelrohr wird auf jeder Seite eine PEEK-Scheibe aufgeschmolzen, anschließend ein Loch in diese Scheiben gebohrt und danach das Glasrohr eingesetzt.
• – Vorgefertigte PEEK-Lochscheibe wird auf das Mantelrohr aufgesetzt und das Glasrohr darin eingesetzt.

In addition to an existing measuring tube (outer diameter 660 μm), a jacket tube made of quartz glass with an inner diameter of 700-800 μm and an outer diameter of less than 3 mm is required. There are two possibilities for welding glass tubes with PEEK:

• - On the jacket tube, a PEEK disc is melted on each side, then a hole drilled in these discs and then inserted the glass tube.
• - Prefabricated PEEK perforated disc is placed on the jacket tube and the glass tube inserted therein.

Subsequently, will the glass tube fused by known methods in a suitable device. Here could a mimicking the hot stamping Fusion process also possible be. In this welding step can be with the help of a suitable form and structures in the Emboss PEEK disc. The used PEEK discs should have a thickness of about 1 mm own.

This Procedure can for Measuring tubes of any length be used. One for that developed device leaves easily adapt to other dimensions. Also can be simply turn the jacket tubes to the desired dimensions. A length adjustment existing jacket pipes requires only a vertical cut.

5 shows a three-dimensional side view of a fiber holder 23 with a jacket tube 3 , a PEEK perforated disc 7 and a fiberglass 25 , The following is on the manufacture of a fiber mount 23 , as in 5 shown, received.

2nd step: production the fiber holder

Next The measuring tubes can be glass fibers with a similar process Weld into casing pipes. This one jacket pipe should have a slightly smaller inside diameter of about 500 μm up to 600 μm have. This is a very symmetrical structure of the connection possible and it may be the same procedure for fixing the measuring tube and fiberglass are used. The assembly is as described below thereby significantly simplified. The assembly can be further simplified if the glass fiber only after welding on the exact length named and polished.

This procedure allows for assembly preparation, in which a very critical process step can be preferred. The production of the jacketed measuring tubes (and glass fibers) is carried out separately and can be thoroughly tested for compliance with the critical tolerances, the mechanical strength and the optical properties. If these meet quality standards, this robust component can still be easily handled.

3rd step: adjustment and fixation of the fluid tube in the cell nucleus (the glass fibers)

On An x-y table is used to fix one of the nucleus and the microscope measured. By a side-mentioned manipulator are the PEEK disc and thus the glass tube is displaced in the X-Y plane to the fluid tube the desired Takes position. Subsequently Apply a small amount of capillary adhesive to the edge of the PEEK disc applied and cured. The adjustment takes place on a marking on the casing pipe or but at the lead, after the welding step was fitted around the jacket pipe.

6 shows a three-dimensional plan view of a base plate 27 for the construction of the flow cell 1 , With the help of the base plate 27 a flow cell can be set up. This is indicated by the base plate 27 a first groove 29 and a second groove 31 on. Advantageously, it is possible to produce long, thin cells with this method, whereby many cells can be arranged next to one another.

4th step: assembly the flow cell

are the glass components in jacket tubes with the same outer diameter fixed, these are in a base plate with appropriate guides inserted.

At least the pre-adjustment of the glass parts to each other takes place via the guides in the base plate. The critical step is now in the connection of the glass fibers and the measuring tubes, which makes a fluid supply perpendicular to the tube axis possible. This is a T-connector 33 needed.

7 shows a three-dimensional line view of the T-connector 33 for the construction of the flow cell 1 ,

This T-connector 33 consists of PEEK and has the same outer diameter as the jacket tubes. In the center axis there is a hole through which the glass fiber is guided into the measuring tube. Perpendicular to this is a bore with an inner diameter which corresponds to the outer diameter of the capillary, via which the fluid is supplied later. The thickness and exact geometry of this T-piece depends largely on the technically acceptable effort and the applied connection technology. The thickness of the T-joint will not exceed 2 mm.

8th shows a three-dimensional side front view of the flow cell 1 with the opto-fluidic connector concept. 9 shows a 3-D view of a fiber connector 35 together the fiberglass 25 , 10 shows a 3-D view of the in the 9 represented fiber connector together with the nucleus 2 , these are partially composed. 11 shows a 3-D view of a mold 37 together with the nucleus 2 , 12 shows a 3-D view of a first mold 9 , as well as a second mold 41 designed for molding the fiber connector 35 , The fiber connector 35 has the T-connector 33 , as well as the glass fiber 25 on.

The Fluid pipes and the glass fibers are held in jacket pipes. Especially the holder of the fluid pipes is done by welding the Fluid tube ends in PEEK perforated discs in a narrow range. The fluid tube is located after welding in a jacket tube.

The PEEK perforated disc, in which the glass tube is welded, has guides (Holes), into which a corresponding counterpart with pins are introduced can.

In this counterpart are the fiber optic and the fluid supply. The mounts of Glass fiber and glass tube serve as plugs.

A Connector structure with pins is very difficult to realize because the demolding on a Entformschräge make necessary, which makes the molds unnecessarily expensive are not sufficient with such complex structures high precision to be finished. The concept has been simplified so that the adjustment contour is applied radially symmetrically. Essential for the Adjustment is that the plug contour in the PEEK exactly to the fluid pipe and the glass fibers fits. By working on a precise lathe the necessary accuracies can be achieved.

Third While the melting of the glass parts in the PEEK parts must be the Glass parts exactly to the connector guides be positioned. This is a guide of the glass parts in one Tool necessary, which fits exactly into the plug geometry, because in this step the PEEK parts correspond to the tool be transformed. The leadership of the fluid tube can by inserting the fluid tube ends in a holder done.

These Adjustment is possible when the fluid tube and the glass fibers in a metal device on Position to the connector contour and hold the PEEK discs in the process of melting on the glass part at the same time in the Connector contour are formed. This allows a much lower Accuracy in the production of PEEK parts.

at the melting process, the nuclear components between two Metal molds laid, the glass parts have to survive, to be in a leadership of the molding tool to the outer contour can be positioned. After positioning these parts are pressed in a device and close above the glass transition temperature heated by PEEK. Did the PEEK exceed this temperature, The molds are pressed against each other, causing the PEEK assumes the inner contour of the mold. Guaranteed the leadership the fluid tube positioning the connector contour.

Essential for the implementation of this concept is the following point:
Is it possible to mold PEEK parts into a connector contour without damaging the glass parts (fluid pipe and glass fiber), which are held in precise guide holes during forming.

For the production The cell nucleus requires three components: fluid tubes, jacket tubes and PEEK disks.

Tubes made by Schott were used as a jacket tube, which offers such DURAN ^® glass tubes as stored goods (Eur 12 per kg). The jacket tube has an inside diameter of about 0.8 ± 0.08 mm and an outside diameter of about 4 ± 0.2 mm. These tubes are suitable as jacket tubes, which on the one hand robustly protect the fluid tube and whose thermal expansion coefficient differs only slightly from that of the quartz glass tube. So it is possible to press on both sides of the PEEK discs even at greater temperature fluctuations, without the rupture of the glass tubes is to be feared. The manufacturing tolerances of these tubes are not suitable for accurate positioning of glass tube and glass fibers to each other. The positioning should be done passively via adjustment structures on the PEEK discs (plug system). The glass tubes were sawn off with a glass saw.

The PEEK discs have a thickness of 1 mm, an outer diameter of 3 mm and an inner hole with a diameter of 700 microns. This one Slices to be formed during assembly requires manufacture no high accuracies.

For the assembly of the nucleus the individual components (casing pipe, PEEK disks, fluid pipe) first together become. The assembly is facilitated by a glass fiber. Difficult during assembly is particularly the insertion of the fluid pipes (outer diameter 660 μm) in the guide hole with an inner diameter of 670 microns.

When the components are brought together, they are put into a mounting device 43 introduced. A 3D side front view of such a mounting device 43 is in 13 shown.

In the outer mounting tube is located in the middle of a bore, the inner diameter of the outer diameter corresponds to the molds and so a precise axial alignment the fluid tube guide guaranteed to each other. This hole must be wide enough so that the jacket tube in it easy to move in spite of the high tolerances, but should not be so big that the jacket tube can touch the fluid tube. Become the nucleus components and the molds in the guide bore introduced, molds and the fluid tube are positioned to each other. Subsequently The punches are threaded against the dies using a thread pressed.

The Mounting device in which the cell nucleus components is compressed, is then heated to a temperature of about 335 ° C. Has the entire device assumed this temperature, the stamps are again against each other driven, whereby the softened PEEK imprinted in the molds. The Temperature of this mounting device may only slightly higher than the glass transition temperature of PEEK's lie. higher Temperatures lead for melting and strong adhesion of PEEK on all metal surfaces.

Subsequently, will through the holes in the stamps hot air passed through the fluid tube to the PEEK, which is now located directly on the outer wall of the glass tubes, to melt on the glass. For this, the walls of the glass tube on a Temperature above 400 ° C to be brought.

After that the mounting device is cooled and the nucleus can be removed become.

The 14 and 15 show different 3-D views of PEEK discs 45 after a heat deformation. After the heat deformation, the discs each have a Prägewulst 47 on. You can also see a connector contour generated by the heat deformation 49 the PEEK discs 45 when molding the originally cylindrical PEEK discs 45 through the inner contour of the mold tools was formed.

As 14 and 15 show the PEEK parts can be molded with this method in the molds. At the same time, the PEEK is pressed against the glass parts, whereby, according to experience, initially only low adhesion but very good thermal contact results. If hot air is subsequently blown in, the intended melting takes place very quickly. If the glass tube becomes too hot, the PEEK can even liquefy so much that it pulls capillary into the space between the fluid jacket and the jacket.

Around an overheating To prevent it is therefore cheap the mounting device at a temperature well below the melting point to keep.

Becomes The nucleus removed from the mounting device, the Molds are pulled from the PEEK parts. Since the fluid pipes in the guide holes lie, can These are only removed if there is sufficient Entformschräge, which allows a parallel removal of the molds.

The Introduce the fluid pipes in the guide bore becomes the more difficult, the shorter the pipe overhang is. In particular, when forming the PEEK discs while the Fluid pipe in the guide bore run without tilting. For However, the production of a cell nucleus, this supernatant is not necessary. Is it possible the fluid tube by a holder in the fluid tube in position To hold, simplifies the assembly and the fluid pipe can with the PEEK area to lock.

The same plug forming principle is used for the fiber plug. Again, the glass component with two guide holes in brass parts positioned and the connector contour in the brass parts in the PEEK imprinted. In contrast to the simple disk geometry of the PEEK components for the nucleus, the fiber connector requires a tee made of PEEK, the side of the inflow the measuring liquid allowed and has a continuous channel for the fiber.

15 shows a three-dimensional line representation of the T-connector 33 , The T-connector 33 For example, it can be made of PEEK and has a plug contour 51 , a lateral fluid inlet 53 , as well as a hole 55 on. The hole 55 is for holding the glass fiber 25 designed.

Also for the Production of the fiber connector is the exact positioning of the Glass fiber to the connector contour by forming the T-piece PEEK done and the remelting of the glass fiber. there is to be feared that the lateral fluid supply strongly deformed or completely melted during reshaping. The forming into the connector contour takes place first only in a small area, the needed Forming pressure is achieved at a comparatively low force. If the connector contour is formed in the entire contour, the Force for another reshaping strongly. As long as this force is not exceeded no deformation of the lateral inflow must be feared.

Of the when forming applied pressure causes a flow of the PEEKs in the middle, eliminating the glass fiber on the back of the tee enclosed by PEEK. The adhesion of the PEEK to the glass fiber is not very high without melting with temperatures above 400 ° C. Indeed can push the glass fiber into a jacket tube on this side be and be glued with epoxy glue, so that the pressure resistance guaranteed is.

For fluidic contacting, compression can be achieved by means of a thread. Alternatively, however, there is also the possibility of a steel cannula 57 into the T-piece and weld there. However, heating of the steel pipe is not sufficient here to produce a fluid-tight connection of steel pipe and PEEK. 17 shows a schematic representation of the T-connector 33 fluidly contacted with the steel cannula 57 ,

First by pressing a likewise heated metal ring or how imaged a wire loop leads to a tight connection.

With the help of such a hot-pressed metal part, a fluid-tight connection can be made. Since the fluidic seal is guaranteed, a much higher compressive strength can be achieved by subsequent bonding with this method. As in the eighteen and 19 As can be seen, results in the fluid-tight connection due to molten plastic material 61 , especially PEEK.

Test cell nucleus

Two PEEK parts with the shape of the T-piece described above without Bore for the glass fiber was fluidly contacted in this way and on a Cell nucleus set. With the help of a press, the nucleus was between pressed these two PEEK parts and water passed.

The press pressed with a force of about 500 N on the nucleus. Subsequently, through the steel capillaries, water at 10 ml / min out conveyed and held after closing a capillary water with up to one hundred bar in the cell nucleus. At over one hundred bars, a leak occurred at the junction of the T-piece and the steel capillary, leaving the cell nucleus undamaged.

• 1) Ein Umformen von mit geringer Präzision gefertigter PEEK-Teile in eine metallische Steckerkontur einfacher Geometrie und hoher Präzision ist möglich.
• 2) Ein Zellkern in dem sich ein Fluidrohr in einem Mantelrohr befindet und das beidseitig von PEEK-Scheiben eingeschmolzen ist, lässt sich herstellen.
• 3) Ein solcher Zellkern ist sehr robust und hält eine Kraft von mindestens 500 N.
• 4) Das Einformen einer Glasfaser in ein T-Stück ist möglich, ohne dass die vorgeformte fluidführende Struktur dabei beschädigt wird.
• 5) Alternativ zu einem Verpressen lassen sich seitlich zugeführte Stahlkapillaren in das PEEK einschmelzen.
• 6) Es ist möglich ein Fluidrohrende eben in PEEK einzuschmelzen, ohne dass das Fluidrohr beschädigt wird.
• 7) Durch Verpressen von zwei Steckerkomponenten aus PEEK, lässt sich eine druckfeste, fluidische Verbindung bewerkstelligen.

The investigations carried out show:

• 1) It is possible to transform low-precision PEEK parts into a metallic connector contour of simple geometry and high precision.
• 2) A nucleus in which a fluid tube is located in a jacket tube and which is sealed on both sides by PEEK discs can be produced.
• 3) Such a nucleus is very robust and holds a force of at least 500 N.
• 4) The molding of a glass fiber into a T-piece is possible without damaging the preformed fluid-conducting structure.
• 5) As an alternative to pressing, laterally supplied steel capillaries can melt into the PEEK.
• 6) It is possible to melt a fluid tube end into PEEK without damaging the fluid tube.
• 7) By pressing two connector components made of PEEK, a pressure-resistant, fluidic connection can be achieved.

Proposal for the embossing tools with non-contact Centering of the glass parts

idea the non-contact Self-centering is that the viscous PEEK when forming to the center is pressed and tried by along the inner bore in the stamping mold to escape. The resulting pressure on the fluid pipe is there the biggest, where the distance between the inner bore and the fluid tube is the smallest. One Balance of power finds if and only if the fluid tube is centered in the inner bore lies. A touch of stamping mold and fluid pipe is therefore for the centering not necessary.

20 shows a 3D view of another embodiment of a manufactured cell nucleus 2 the flow cell 2 ,

For the nucleus the following glass parts are necessary: a jacket tube made of glass (length 4.8 mm, outside diameter about 4 mm and an inside hole diameter of 0.8 mm) and a fluid tube with length 7.8 mm and an outer diameter of 0.66 mm.

The PEEK discs used for this purpose should have the following following assembly Own form. Whereby, when forming a bead on the plane sealing surface will form, whose inner diameter is after the inner hole of the Forming tool. Intended bead diameter 0.7 mm, the Height depends on the process parameters.

The associated embossing form, embossed with the PEEK disc It should look like this

The front side is the negative form of the PEEK disc. Through the entire embossing form, a 0.7 mm bore drags, in which the fluid pipe lies and through which later hot air is blown. On the back there is a countersunk hole with an internal thread 63 , In this internal thread, a guide pin can be screwed, which ensures the lateral positioning of the fluid pipe. This guide pin continues to help in removing the nucleus from the mounting device.

To the Forming the components are used in the mounting device. The mounting device has a center bore a diameter the outer diameter the jacket pipe as possible exactly corresponds, have to However, the casing pipes in this hole still move well. The embossing molds are also inserted into this hole. Farther has the mounting form on each side a bore with internal thread, in the stamp with an external thread can be screwed.

The Stamps that are screwed into the mounting device, have a fine external thread and on the part of the protruding from the mounting device one Hexagonal shape on which a socket wrench can attack.

Of the guide pin sticks out a piece out of the stamp. On the protruding end of the guide pin can be unscrewed to remove the nucleus, a fixation plate are, when unscrewing the punch from the stamping mold pulling out the inner bore.

• 1. Einsetzen des Mantelrohres und der Vorgeformten PEEK-Scheiben in die Innenbohrung der Montagevorrichtung
• 2. Beidseitiges Einsetzen der Prägeformen sowie Einschrauben von Stempel und Führungsstift von der ersten Seite.
• 3. Einsetzen des Fluidrohres in die Bohrung. Laterale Positionierung durch ersten Führungsstift.
• 4. Einschrauben des zweiten Stempels und des zweiten Führungsstiftes. Dabei werden die Stempel moderat festgezogen, die optimale Position des zweiten Führungsstiftes muss erprobt werden.
• 5. Erwärmen der Vorrichtung auf die Umformtemperatur.
• 6. Erneutes Festdrehen der Stempel – optimale Kraft muss erprobt werden.
• 7. Nach dem Umformen – herausdrehen der Führungsstifte und durchströmen mit Heißluft zum Verschmelzen.
• 8. Wiederum eindrehen der Führungsstifte in die Prägeformen und festdrehen der Fixierungsplatte.
• 9. Herausdrehen der Stempel und Entnahme des Zellkerns.

The individual production steps with this device are as follows:

• 1. Inserting the jacket tube and preformed PEEK discs into the internal bore of the fixture
• 2. Insert the embossing forms on both sides and screw in the punch and guide pin from the first side.
• 3. Insert the fluid tube into the hole. Lateral positioning by first guide pin.
• 4. Screw in the second punch and the second guide pin. The stamps are moderately tightened, the optimal position of the second guide pin must be tested.
• 5. Heating the device on the Umformtem temperature.
• 6. Re-tighten the punches - optimum strength must be tested.
• 7. After forming - unscrew the guide pins and flow through with hot air to fuse.
• 8. Screw the guide pins into the stamping dies again and tighten the fixing plate.
• 9. Unscrew the punches and remove the cell nucleus.

fiber connectors

Looking the fiber plug

The Similar to assembly tools those for the nuclear assembly. Significant differences are especially in the Area of embossing forms.

There the tee Of course, the embossing tools must also be shaped differently on both sides be different. It is essential, however, that here the positioning the glass fiber by the exact fit in the inner holes of the embossing dies (= 0.44 mm or glass fiber diameter) is determined. The glass part here lies directly on the stamping mold at.

The backs the embossing forms in turn allow the screwing of guide pins. These serve essentially demoulding. However, this must be the guide pin for the Hollow back so that the fiber can be led out.

The individual production steps are also hardly different those in the manufacture of the nucleus. However, here on the Melting with hot air first waived. By forming the PEEK puts on the rear Part of the tee around the glass fiber. This molding seals, but causes effected no high liability. The necessary adhesive force is after the forming of the tee with the glass fiber by gluing fiber connector with the jacket tube achieved.

variant 2 requires a molding of the PEEK parts to larger areas without Entformschräge what according to previous experience demolding from the mounting device very difficult and therefore initially deferred. It is to note that although in the manufacture of the fiber connector the Tee Outside also no draft angle having. On these side walls However, it is not formed.

Claims (9)

Optofluidic connector with - a glass fiber ( 25 ), - a T-connector ( 33 ), wherein the T-connector ( 33 ) fluid-tight with the glass fiber ( 25 ) connected is. Optofluidic connector according to claim 1, wherein the T-connector ( 33 ) has molten and resolidified PEEK. Optofluidic connector according to claim 1 or 2, wherein the T-connector ( 33 ) a lateral fluidic inflow ( 53 ) having. Opto-fluidic connector according to one of the preceding claims, wherein the T-connector ( 25 ) a centric bore ( 55 ) into which the inflow ( 53 ) and into which the glass fiber ( 25 ) is introduced. Optofluidic connector according to one of the preceding claims, wherein, the T-connector ( 33 ) a connector contour 49 having. Optofluidic connector according to one of the preceding Claims, with a contoured counterpart, wherein, the connector contour is designed with the corresponding contoured counterpart to make a fluid-tight connection. Optofluidic connector according to one of the preceding claims, wherein, with the T-connector ( 33 ) connected glass fiber protrudes from this so that it can be introduced into a fluid channel of the counterpart .. Optofluidic connector according to one of the preceding claims, wherein the counterpart is a PEEK perforated disc ( 7 ) having. Flow cell with an optofluidic connector according to one of the preceding claims.