WO2009121363A1

WO2009121363A1 - Adjustable chip holder

Info

Publication number: WO2009121363A1
Application number: PCT/DK2009/000081
Authority: WO
Inventors: Detlef Snakenborg
Original assignee: Danmarks Tekniske Universitet Dtu
Priority date: 2008-04-02
Filing date: 2009-04-02
Publication date: 2009-10-08
Also published as: EP2108452A1

Abstract

An adjustable microchip holder for holding a microchip is provided having a plurality of displaceable interconnection pads for connecting the connection holes of a microchip with one or more external devices or equipment. The adjustable microchip holder can fit different sizes of microchips with varying positions of connection holes.

Description

ADJUSTABLE CHIP HOLDER

FIELD OF THE INVENTION

This invention, in general, relates to the field of micro systems. In particular, the present invention provides an adjustable chip holder for microchips with varying positions of the connecting ports.

BACKGROUND OF THE INVENTION

Since the first integrated circuit was invented, miniaturization has become an important research topic in both electronic and non-electronic devices. In the late 1970s, miniaturization was extended to mechanical devices with electronics, which is now known as microelectromechanical systems (MEMS). MEMS research has been largely encouraged by the first introduction of miniaturized total analysis systems and MEMS systems are widely employed in areas from biomedical and drug delivery to space and fuel cell microfluidic systems. These systems have been reduced in size to micro scale for the realization of fully integrated micro systems, such as lab- on-a-chip or a micro total analysis system. Major advantages of miniaturization are the drastic decrease in chemical reaction time and less consumption of expensive chemical reagents, as well as enhancement of reliability. On the other hand, as such fully integrated microfluidic systems are expensive to realize in a chip or analysis system, it is essential that the functionality is as desired. It is therefore required that the systems are thoroughly tested prior to the final miniaturization. Microfluidic systems are therefore well-suited for experimental settings or in the context of research.

One of the key elements of micro systems are microchips used e.g. for analyzing fluidic samples or process electronic data. These microchips are normally connected to external devices through chip holders. The technological bottlenecks in microfluidics are the interface with existing equipment. It is hard to meet the increasing demands concerning pressure, dead volume and materials used for interconnection. Microfluidic connection such as a holder enable user friendly interconnection between microfluidic chip and peripheral equipment such micropump, biochemical sensor, analysis equipment. In general, microchips comprise connection holes on one side (top or bottom) of the chip. Such connection points can be fluidic, electrical or the like. In microfluidics, the chips are connected to the external devices by e.g. gluing tubes directly on the connection holes of the chip. As this must be done with accuracy, this is a very time-consuming process. In electronics, the microchips wires are soldered on the ports. A more time- economic possibility is to make custom made holders for specific microchips.

Different principles for chip holders such are known in the art that have been developed either for specific application (analysis under pressure or under microscope, also holder comprising control device for micromachining) and/or for specific chips design. However, all provide standardized fixed position for holding a chip. The reason is that chip holder fabrication is made according to the chip design. In other words the chip holder has to be compatible with the size, shape, and number of holes placed on the chip for connection with external devices. Most prior art holders like the product of Micronit company, comprise a lower part and an upper part. The upper part is designed to fix a micro-fluidic chip in the opening of the lower part by screwing knurled nuts to the threaded bolts of lower part (mechanical pressure). The upper part comprises a plurality of connection holes that match number and position of holes on the micro-fluidic chip which can be fixed between lower part and the upper part. The connection holes allow connection of the micro-fluidic chip with external device such pump, mixer, analysis equipment (NMR, MS, HPLC), detection system (camera, microscope), electronic control unit, connector to PC as a few examples. Such holders are often designed in a way that only one type of micro chip design can be adapted in the holder. For example, Micronit Microfluidics company offers various analysis possibilities with their different chips such microreactor chips, micromixer chips, standard capillary electrophoresis chips, electrode capillary electrophoresis chips, microtiter plate. However, these chips are only compatible with their specific holder restricting the user to costly approach and/or less flexible research or analysis set-ups. One drawback is that all holders available today are made specific to the design of the chip. In other words chips from thinXXS company for example can not be adapted to the holder from Micronit company and vice versa. In addition, very often the user has to align the holder to the equipment with alignment nuts. However, some prior art holders can be moved in x- and y- direction for alignment of microfluidic device with the analytic equipment. For example, WO 2007/043561, which describes a holder which comprises an opening part where the microdevice is fixed by pressure using clamping system with springs. The holder is placed on a drive base on a microscope stage (external equipment). The drive base is driven the entire holder to any position in two-dimensional directions. In other words, the holder is configured such that the microfluidic device can only be placed in one single position and provides only few possibilities for interconnections between the microfluidic device and the external equipment. Also, the movement in two- dimentional directions is restricted to the holder for alignment to the analytic unit. Therefore the use of this type of holder is limited to specific type of microdevice and/or analytic set-ups. The advantage here is that alignment of the holder can be done as many times as needed during the analysis.

OBJECT AND SUMMARY OF THE INVENTION The objective of the present invention is to solve the above mentioned problems.

In one embodiment the microchip holder for holding a microchip comprises at least one interconnection pad whose position can be changed in a two dimensional plane such that the interconnection pad can be aligned to the position of a connection hole on the microchip, connecting the microchip with the interconnection pad connected to at least one external device. The microchip holder is advantageous as it provides a flexible and reliable connection between microchips and external devices or equipment in microfluidic, microelectrical, and microoptical systems. The highly configurable microchip holder can be used many times, as it can be (re)adjusted to fit any microchip varying in both size, position of connection holes, and purpose. Further the microchip holder of the present invention eliminates the need for special skills and reduces the time needed to build micro systems. Consequently the cost of configuring micro systems is reduced considerably. The microchip holder is therefore well suited in research and educational settings.

In another embodiment the microchip holder the interconnection pad is adjustable in a first direction using a rail system comprising at least one rail, said rail having at least one interconnection pad adjustable in the direction of said rail. In a further embodiment, the microchip holder the rail is adjustable in a second direction. Together these two embodiments constitute the two- dimensional plane mentioned above. The advantage of the rail system is that it, provides flexibility in terms of configuring the microchip holder to establish a connection between a microchip and external devices or equipment. Further it enables the user to provide a precise positioning of the interconnection holes corresponding to the connection holes of the microchip. The microchip holder can comprise as many rails with pads as needed to align with the exact number and positions of connecting holes on a define microchip. As a result, in contrast to prior art solutions, all chip design (standard and/or specifically made) can be adapted in the inventive chip holder. This is an economically particularly advantageous solution in experimental and analysis set-ups, and provides a very flexible connection device. Also, no additional adjustment of the new holder to external equipment is necessary once the microchip is positioned in the holder. In a further embodiment, the rail of the microchip holder comprises an elongated channel and the interconnection pad comprises a collet positioned in the elongated channel adapted to be adjusted in the direction of the elongated channel. The adjustment mechanism is advantageous, as it is very easy to operate.

In yet another embodiment of the microchip holder, the interconnection pads are adapted to interconnect the connection hole of the microchip and the external devices with a transport channel for enabling the transport of a fluid between the microchip and the external device. In another embodiment the interconnection pad comprises an elastomeric element that allows establishing a sealed interconnection between the interconnection pad and a hole on the microchip. In a further embodiment of the microchip holder, the elastomeric element is an elastic pad. Apart from the advantages listed above, the advantage of these embodiments is that they, taken alone or in combination, provide a sealed connection between a microchip and external devices. This sealed connection could be a fluidic connection between a microfluidic chip and external devices. Hereby the connection pad made of elastomeric material provides not only connection holes, but also a sealing pad adapted to form a sealing which is impermeable to a fluid in the microfluidic chip.

In another embodiment the microchip holder further comprises a cover (upper part) for pressing the microchip and thereby the connection hole towards the interconnection pads in the microchip holder. In yet another embodiment the microchip holder comprises a suction device for sucking the microchip and thereby the connection hole towards the interconnection pads in the microchip holder. The advantage of these embodiments is that they ensure a reliably connection between the microchip and the external devices. Thus the chip holder can be configured such that the microchip is fixed in the chip holder by a mechanical or manual pressure or the like. In a further embodiment, the microchip holder comprises a surface part for positioning the microchip, wherein the surface part comprises at least one interconnection pad. Here the advantages are as outlined above.

In another embodiment the microchip holder comprises a frame surrounding the microchip and corresponding to the dimensions of the microchip, wherein the frame comprises at least one interconnection pad. This is an advantage when the microchip comprises connection holes on the sides of the microchip, whereby the microchip holder can be configured to accommodate the characteristics of a greater variety of the position of the connection holes of microchips. A further advantage is that the frame aligns and fixates the microchip in the microchip holder.

In yet another embodiment of the present invention, the microchip holder comprises means for adjusting the size of the frame enabling the holder to fit dimensions of different microchips (301). This is advantageous because the microchip holder can accommodate a great variety of dimensions of the microchips.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, preferred embodiments of the invention will be described referring to the figures, where

figure 1 illustrates a rail system comprised in an adjustable chip holder for holding a microchip in accordance with one embodiment of the present invention;

figure 2 illustrates a microchip holder according to the present invention;

figure 3 illustrates an exploded perspective of a microchip holder system according to the present invention; figure 4 illustrates a perspective of a chip holder comprising interconnection elements for connecting to a microchip with connection holes on the side of the microchip.

DESCRIPTION OF EMBODIMENTS

Figure 1 illustrates a rail system 100 comprised in an adjustable chip holder for holding a microchip in accordance with one embodiment of the present invention. The rail system 100 comprises an elongated channel 104 comprising a collet 102 arranged in the channel 104 for adjusting the position of the collet 102 in the direction of the elongated channel 104. An interconnection pad 103 is comprised by the collet 102 and is, as stated, free to move in the elongated channel 104. The interconnection pad 103 enables a connection to the connecting holes of a microchip 301. The rail system 100 further comprises two side holes 105a, 105b to position the rail 101 in a second direction in the adjustable chip holder (not shown). Further, the rail movement in this second direction enables a movement of the interconnecting pad 103 to a specific position required by the connection holes of the microchip. Thus, the rail 101 can be aligned in a two-dimensional plane defined by e.g. an x-axis and a y-axis. The interconnection pad 103 can further be connected to external devices, through e.g. a wire or tube, to connect the microchip to these external devices (not shown). In microfluidic systems the interconnection pads 103 can be made of e.g. a flexible and/or elastomeric and/or polymeric material, which enables a sealed connection to the connection holes of a microfluidic chip. The connection pads 103 can have different shapes, such as circular or elliptical. In microelectrical systems the interconnection pads 103 could be an interface for establishing an electrical connection to a microelectrical chip. In microoptical systems the interconnection pads 103 could be an interface for establishing an optical connection to a microoptical chip. Figure 2 illustrates a perspective of an adjustable microchip holder 200 according to the present invention. The microchip holder 200 comprises a number of rail systems 100, as described in figure 1. The chip holder 200 enables a connection between a microchip and external devices, such as sensors, actuators, fluid pipes or control devices etc. The microchip holder 200 comprises a frame 207, wherein two rods 202 are arranged parallel to each other, in opposite sides of the frame 207. The rods 202 extend through the two sides holes 105a and 105b of the rail system 100. Each rail system 100 can be moved along the longitudinal axis of the two rods 202. The collet 102 and the comprised interconnection pad 103 can, as described in figure 1 , be moved in a direction along the elongated channel 104, whereby the interconnection pad 103 can be moved in a two-dimensional plane given by the rail system 100 and the rods 202. In this way the microchip holder 200 can be adapted to the characteristics of a microchip, that is, the interconnection pads 103 can be adjusted to the position of the connection holes of a microchip, whereby a connection between the microchip and external devices can be obtained. The microchip (not shown) is placed on the surface part constituted by the plane of the interconnection pads 103. Thereby the microchip can rest on the interconnection pads 103 and optionally be supported by the sides of the hole (not indicated) in the top of the frame 207. After use the microchip holder 200 can simply be (re)adjusted to fit another microchip with different positions of the connection holes. In an alternative embodiment the rail system 100 could be guided in or by other rail(s) or rods placed at e.g. the top, side (see figure 4) or bottom of the microchip holder 200, or alternatively a combination of these embodiments. In another embodiment the hole (not indicated) in the top of the frame 207 of the microchip holder 200, wherein the microchip is placed, can be adjusted, to fit different sizes of microchips.

Figure 3 illustrates an exploded perspective of a microchip holder system 300, where a microchip 301 is inserted into the chip holder 200 and pressed against the surface part (lower part) constituted by the connection pads elements 103 with a cover 302 (upper part), whereby a connection between the microchip 301 and external devices is obtained. The microchip holder 200 can be adjusted to the individual characteristics of a microchip as described in figure 2. In this embodiment the position of the cover 302 (upper part) is fixed by the male/female connection between the protrusions 206a-d of the holder 200 and the holes or indentations 306a-d of the cover (upper part) 302. The cover (upper part) 302 can further be fixed to the frame 200 using screws, threaded bolts in combination with nuts, or durable and/or replaceable snap functions. In an alternative embodiment, the microchip 301 also can be pressed or held against the chip holder 200 by other means, such as a suction device. This could be done by applying negative pressure on e.g. defined areas of the microchip 301 or the cover (upper part) 302.

Figure 4 illustrates a perspective of a chip holder 200 comprising a frame 207 and interconnection pads 103 for connecting to a microchip with connection holes on the side of the microchip (not shown). The frame 207 comprises a rail 104 in which the interconnection pads 103 are arranged. The interconnection pads 103 are comprised by a collet (not indicated), resembling the collet 102 disclosed in figure 1. The interconnection pads 103 can be moved along the rail 104 and thereby placed in a position corresponding to the connection holes of a microchip (not shown). The frame 207 further comprises an opening (not indicated) along the inner side of the frame 207 facing the center of he chip holder 200, and is embodied in connection to the rail 104. By sliding the microchip (not shown) into this opening, the microchip is aligned and fixed in the holder 200. A connection between the microchip and external devices can hereby be obtained. After use, the microchip can simply be removed by pulling it out of the openings of the frame 207. The chip holder 200 could also comprise interconnection pads 103 in the bottom of the frame 207 as e.g. disclosed in figure 2. This would enable a connection between external devices and a microchip comprising connecting holes at the bottom and side of the microchip. Here the microchip would be held in place by e.g. lateral stress and screwing.

The chip holder 200 configuration as described in figure 4 also brings along the advantage of providing a compact holder design with no upper and lower part to fix the chip. In other words, no pressure for sealing the chip in the holder from the top or bottom is required. A simple pressure using e.g. a screw for example from the side of the holder would be sufficient as sealing mechanism. Hereby yet another advantage is provided in that the top and/or bottom of the microfluidic chip is accessible for e.g. optical inspection.

In an alternative embodiment the microchip holder could be frameless, such that the microchip would be held in place by the interconnection pads alone or alternatively combined with a supportive fixation of the microchip in at least one fixation point enabled by holes/protrusion on the bottom side of the microchip, where the counterpart of the microchip holder could be integrated in the rails like the interconnection pads. In a further embodiment the collets of the rail system could optionally fit different connection or fixation devices.

While this invention has been described in detail with reference to certain preferred embodiments, it should be appreciated that the present invention is not limited to those precise embodiments. Rather, in view of the present disclosure, which describes the current best mode for practicing the invention, many modifications and variations would present themselves to those skilled in the art without departing from the scope and spirit of this invention, which is limited only by the appended claims. REFERENCES

100 rail system

101 rail

102 collet

103 interconnection pad

104 elongated channel

105a,b side hole

200 microchip holder

202 rod

206a-d protrusions or hole

207 frame

300 microchip holder system

301 microchip

302 cover (upper part)

306a-d hole, indentation

Claims

1. A microchip holder (200, 300) for holding a microchip (301), characterized in that, said microchip holder (200, 300) comprises at least one interconnection pad (103) whose position can be changed in a two dimensional plane such that said interconnection pad (103) can be aligned to the position of a connection hole on said microchip (301) connecting the microchip (301) with said interconnection pad (103) connected to at least one external device.

2. A microchip holder (200, 300) according to claim 1 , characterized in that said interconnection pad (103) is adjustable in a first direction using a rail system (100) comprising at least one rail (101), said rail (101) having at least one interconnection pad (103) adjustable in the direction of said rail (101).

3. A microchip holder according to claim 2, characterized in that said rail is adjustable in a second direction (202).

4. A microchip holder (200, 300) according to any of claims 1-3, characterized in that said rail (101) comprises an elongated channel (104) and said interconnection pad (103) comprises a collet (102) positioned in said elongated channel (104) adapted to be adjusted in the direction of said elongated channel (104).

5. A microchip holder (200, 300) according to any of claims 1-4, characterized in that said interconnection pads (103) are adapted to interconnect said connection hole of said microchip (301) and said external devices with a transport channel for enabling the transport of a fluid between said microchip (301) and said external device.

6. A microchip holder (200, 300) according to any of the claims 1-5, characterized in that said interconnection pad (103) comprises an elastomeric element that allows establishing a sealed interconnection between the interconnection pad and a hole on said microchip (301).

7. A microchip holder (200, 300) according to claim 6, characterized in that said elastomeric element is an elastic pad.

8. A microchip holder (200, 300) according to any of claims 1-7, characterized in that comprising a cover (302) for pressing the microchip

(301) and thereby said connection hole towards the interconnection pads (103) in said microchip holder (200, 300).

9. A microchip holder (200, 300) according to any of claims 1-8, characterized in that the microchip holder (200, 300) comprises a suction device for sucking the microchip (301) and thereby said connection hole towards the interconnection pads (103) in said microchip holder (200, 300).

10. A microchip holder (200, 300) according to any of claims 1-9, characterized in that said microchip holder (200, 300) comprises a surface part for positioning said microchip (301), wherein said surface part comprises at least one interconnection pad (103).

11. A microchip holder (200, 300) according to any of claims 1-10, characterized in that said microchip holder (200, 300) comprises a frame

(207) surrounding said microchip (301) and corresponding to the dimensions of said microchip (301), wherein said frame (207) comprises at least one interconnection pad (103).

12. A microchip holder (200, 300) according to claim 11 , characterized in that said microchip holder (200, 300) comprises means for adjusting the size of the frame (207) enabling the holder to fit dimensions of different microchips (301).