AT526051B1 - Holding device for holding a microfluid chip and method for using a microfluid chip - Google Patents

Abstract

The invention relates to a holding device (1) for holding a microfluid chip (2), wherein the holding device (1) has a chip carrier (3) for, in particular releasably, arranging a microfluid chip (2) in order to pass through a fluid inlet (6) of the microfluid chip ( 2) supply a fluid, in particular oil, into a microfluid channel system (8) of the microfluid chip (2). For an optimized operational application, it is provided that the holding device (1) has a fiber-optic pressure sensor (14) in order to measure a fluid pressure of the fluid supplied into the microfluid channel system (8) when in use, and/or the holding device (1) has a plurality of individually controllable heating elements (27) in order to heat the microfluid chip (2) or the fluid in a controlled manner when in use. The invention further relates to a method for using a microfluid chip (2).

Description

Description

HOLDING DEVICE FOR HOLDING A MICROFLUID CHIP AND METHOD FOR USE OF A MICROFLUID CHIP

The invention relates to a holding device for holding a microfluid chip, wherein the holding device has a chip carrier for the, in particular detachable, arrangement of a microfluid chip in order to supply a fluid, in particular oil, into a microfluid channel system of the microfluid chip via a fluid inlet of the microfluid chip.

The invention further relates to a method for using a microfluid chip, wherein a microfluid chip is arranged on a chip carrier of a holding device for holding the microfluid chip, a fluid, in particular oil, being supplied into a microfluid channel system of the microfluid chip via a fluid inlet of the microfluid chip.

To investigate the flow behavior of a fluid in a rock from underground deposits, it is known to simulate a rock structure of the rock with a microfluid chip, wherein a microfluid channel system of the microfluid chip is designed to correspond to a rock porosity or a rock channel system of the rock. For this purpose, it is usually provided that the microfluid chip is held with a holding device and a fluid is introduced into the microfluid channel system via a fluid inlet of the microfluid chip in order to examine the flow behavior of the fluid in the microfluid channel system, usually under microscopic observation. For example, with a view to exploring the extraction of oil from the rock, oil can first be introduced into the microfluid channel system in order to then investigate the possibility of extracting the oil from the rock by introducing water into the microfluid channel system. The holding device usually has a chip carrier for holding the microfluid chip, which is generally plate-shaped. The microfluid chip is usually designed to be able to transmit light in order to observe the flow behavior of the fluid in the microfluid channel system with light irradiating the microfluid chip using a microscope.

[0004] This is where the invention comes into play. The object of the invention is to provide a holding device of the type mentioned at the outset, which enables an optimized application of a microfluid chip, in particular optimized investigation of a flow behavior of a fluid supplied to the microfluid chip.

Another object of the invention is to provide a method of the type mentioned at the outset, which enables an optimized application of a microfluid chip, in particular an optimized investigation of a flow behavior of a fluid supplied to the microfluid chip.

The object is achieved according to the invention in that, in a holding device of the type mentioned at the outset, the holding device has a fiber-optic pressure sensor in order to measure a fluid pressure of the fluid supplied into the microfluid channel system when in use, and/or the holding device has a plurality of individually controllable heating elements in order to heat the microfluid chip or the fluid in a controlled manner when in use.

The basis of the invention is the idea of simulating the behavior of a fluid in a rock with the microfluid chip and a fluid added to the microfluid channel system with precisely defined boundary conditions. An accurate representation of a fluid pressure and/or a temperature of the fluid in the microfluid channel system has proven to be particularly relevant in this regard. However, an exact determination or determination of fluid pressure and/or temperature of the fluid has proven to be difficult, particularly due to the usually very small volumes of microfluid channels of the microfluid channel system. This applies in particular to an investigation of the behavior of microfluid flows of the fluid in the microfluid channel system of the microfluid chip. Accordingly, it is advantageous if the holding device is designed to enable precise fluid pressure measurement and/or precise temperature determination of the fluid in the microfluid chip in an operational state. This can be achieved if the holding device is fiber optic

Pressure sensor for fluid pressure measurement and / or several individually controllable, in particular adjustable, heating elements for heating the microfluid chip or the fluid in the microfluid channel system. The fiber-optic pressure sensor enables fluid pressure measurement with high accuracy, in particular as explained below. The several individually, in particular separately, controllable heating elements enable a homogeneous temperature to be set with high precision along the microfluid chip or along the fluid in the microfluid channel system. This means that the behavior of the fluid can be realistically simulated or recreated and examined as a result of precisely known boundary conditions.

A meaningful fluid pressure measurement of a fluid in the microfluid channel system has proven to be difficult to implement, particularly due to the generally small volumes of microfluid channels of the microfluid channel system or a fluid introduced into them. In particular, a pressure measurement often leads to a change in the system to be measured of fluid located in the microfluid channel system, so that an accurate and reliable pressure measurement is prevented or the system to be measured is impaired for an examination. This can, for example, lead to microstructural, often microbiological, processes that are intended to take place in the microfluid channels taking place in the area of a pressure sensor. The relevant cause is often that conventional pressure transducers usually cause a dead volume, which is a multiple of the volume of the microfluid channel system or its microfluid channels. A typical volume of a microfluidic channel system is, for example, around 20 il. Common pressure transducers usually have a dead volume of more than 200 hl. The dead volume is usually a volume that is introduced into a system to be measured by a pressure sensor or that influences the system to be measured caused by the pressure measurement. It has been shown that the aforementioned problem can be solved by using a fiber-optic pressure sensor to measure the fluid pressure of the fluid in the microfluid channel system or by the holding device having a fiber-optic pressure sensor for this purpose. This makes it possible to carry out a fluid pressure measurement of the fluid with generally negligible impairment of the measuring system of fluid located in the microfluid channel system. A fiber-optic pressure sensor can be connected to the microfluid chip as part of the holding device without significantly affecting the design of the microfluid channel system. The fiber-optic pressure sensor can be coupled to the microfluidic chip or the microfluidic chip with preferably negligible dead volume. As a result, an application or an examination of a fluid supplied to the microfluid chip, in particular its behavior, usually flow behavior, can be optimized.

The microfluid chip usually has a microfluid channel system and a fluid inlet in order to supply a fluid to the microfluid channel system via the fluid inlet. A fluid located in the microfluid channel system can be removed from the microfluid channel system via a fluid outlet of the microfluid chip. The fluid inlet or fluid outlet is usually connected to the microfluid channel system in a fluid-conducting manner. The microfluid channel system is usually connected to a plurality of fluid channels connected to one another in a fluid-conducting manner. In this way, a rock porosity or a rock channel system, through which a fluid can be guided, can be simulated with the microfluid chip or the microfluid channel system. A microfluid channel system usually has a volume for holding fluid between 5 µl and 100 µl, in particular between 10 µl and 50 µl, preferably between 15 µl and 30 µl, in particular about 20 µl. A diameter of the fluid channels is generally smaller than 1000 μm, in particular smaller than 500 μm, preferably smaller than 100 μm, particularly preferably smaller than 50 μm, particularly preferably smaller than 10 μm, particularly preferably smaller than 1 μm. The microfluid chip is usually plate-shaped. The microfluid chip usually has a length and a width of less than 10 cm, in particular less than 8 cm. The height of the microfluid chip is usually orthogonal to a length and width of the microfluid chip, with the height generally being smaller than the length and width of the microfluid chip.

The chip carrier is usually designed to arrange or fix a microfluid chip, in particular releasably, on the holding device. The holding device can have a fluid supply device with which a microfluid chip arranged with the chip carrier is supplied with fluid

can be supplied, usually via a fluid inlet of the microfluid chip.

[0011] It is practical if the fiber-optic pressure sensor is coupled to the chip carrier in such a way that the fiber-optic pressure sensor is connected to the microfluid channel system in the operational state, in particular in a fluid pressure-transmitting manner, in order to measure a fluid pressure of the fluid supplied into the microfluid channel system.

Typically, the microfluidic chip with the chip carrier can be arranged in an imaginary arrangement plane to produce the operational state, the arrangement plane being oriented parallel to a longitudinal extent and width extent of the microfluidic chip. An observation line of sight along which the microfluid chip is usually observed when in use is generally oriented transversely, in particular orthogonally, to the arrangement plane. The microfluid chip is usually designed to be able to transmit light, in particular against the observation line. As a rule, the microfluid chip has two light-transmittable or transparent cover surfaces, usually formed with or made of quartz glass, between which the microfluid channel structure is formed. The cover surfaces are each oriented parallel to a longitudinal extent and width extent of the microfluid chip.

Use state usually refers to a state when a microfluid chip with the chip carrier is arranged on the holding device in order to examine a fluid located in a microfluid channel system of the fluid or a fluid to be supplied to the microfluid channel system, in particular its behavior.

The fiber-optic pressure sensor usually has a measuring head in order to measure a fluid pressure acting on the measuring head with the fiber-optic pressure sensor when in use. For this purpose, the fiber-optic pressure sensor, in particular the measuring head, usually has a measuring surface in order to use the fiber-optic pressure sensor to measure a fluid pressure acting on the measuring surface, usually by, in particular elastic, deformation of the measuring surface. The measuring head is usually arranged in such a way, in particular coupled to the chip carrier, that in the operational state the measuring head is in communication with a fluid supplied to the microfluid channel system in a fluid pressure-transmitting manner. The measuring head is usually arranged in such a way that it is guided essentially from a lateral direction to the chip carrier or, in the use state, to the microfluid chip and is coupled to it. This is particularly true in a top view of the arrangement level. The lateral direction is usually oriented essentially parallel to the arrangement direction.

The fiber-optic pressure sensor can be coupled to the chip carrier in such a way that, in the use state, the measuring surface is connected to the microfluid chip, in particular the microfluid channel system, in contact with the fluid, in particular connects to the microfluid channel system, in order to measure the fluid pressure of the fluid with the measuring surface.

[0016] It is advantageous for high accuracy if the chip carrier has a fluid transmission channel, which fluid transmission channel is connected to the microfluid channel system of the microfluid chip in a fluid-conducting manner in the use state, in particular adjoins it, the measuring surface of the fiber-optic pressure sensor being used to measure a fluid pressure of a fluid in the fluid transmission channel connected to the fluid transfer channel. It is usually provided that a fluid which is supplied to the microfluid channel system fills the fluid transfer channel. The measuring surface usually connects to the fluid transfer channel for fluid pressure measurement. In this way, the fluid pressure of the fluid in the microfluidic channel system can be measured by measuring the fluid pressure of the fluid in the fluid transfer channel. It is advantageous if the fluid transfer channel has a volume for receiving the fluid, which volume is smaller than 10 μl, in particular smaller than 5 μl, preferably smaller than 1 μl, particularly preferably smaller than 0.5 μl. A dead volume of the fluid pressure measurement or the fiber-optic pressure sensor can thereby be kept particularly small.

The chip carrier usually has a supply channel in order to supply fluid to the fluid inlet of the microfluid chip via the supply channel when in use. It is expedient if the supply channel is connected to the fluid inlet in a fluid-conducting manner when in use, in particular

connects to this. It is advantageous if the measuring surface or the fluid transfer channel is arranged in such a way that, when in use, it connects to a section of the microfluid chip in which the fluid inlet of the microfluid chip is located. It is practical if the fluid transfer channel connects to the supply channel. It is usually provided that fluid supplied to the supply channel is guided into the fluid transfer channel for the fluid pressure measurement.

It is expedient if the holding device has a supply valve, so that in the operating state with control, in particular regulation, of the supply valve, a supply of fluid to the fluid inlet can be controlled, in particular regulated. The chip carrier usually has an input connection which, when in use, is connected in a fluid-conducting manner to the fluid input of the microfluid chip in order to supply fluid to the fluid input via the input connection. For this purpose, the supply channel can be designed as part of the input connection. The supply valve can be connected to the inlet port and can be designed to control, in particular regulate, a flow of fluid through the inlet port when in use. For example, the holding device can have a supply line which is connected to the inlet port in a fluid-conducting manner, the supply valve being arranged between the supply line and the inlet port in order to use the supply valve to control, in particular regulate, an inflow of fluid from the supply line to the inlet port. The holding device can have a discharge valve, so that in the operating state with control, in particular regulation, of the discharge valve, a discharge of the fluid from the fluid outlet can be controlled, in particular regulated. The chip carrier usually has an output connection which, when in use, is connected to the fluid outlet of the microfluid chip in a fluid-conducting manner in order to drain fluid from the fluid outlet via the output connection. The discharge valve can be connected to the output port and can be designed to control, in particular regulate, a flow of fluid through the output port when in use. For example, the holding device can have a discharge line which is connected to the output port in a fluid-conducting manner, the supply valve being arranged between the discharge line and the output port in order to use the discharge valve to control, in particular regulate, an outflow of fluid from the output port into the discharge line. The holding device can have one or more operating devices, for example operating levers, with which the supply valve and/or discharge valve can be controlled, in particular regulated, in particular separately from one another. The holding device can expediently have an electronic control unit which is designed to control, in particular regulate, the supply valve or discharge valve.

[0019] It is advantageous if the chip carrier and the measuring head are detachably connected to one another. It has proven useful if the chip carrier and the measuring head are connected to one another in a form-fitting and/or force-fitting manner, usually in a detachable manner. Although less preferred, the measuring head and the chip carrier can be cohesively connected to one another. It is advantageous if the chip carrier has a measuring head receptacle and the measuring head has an outer casing that corresponds in shape to the measuring head receptacle, the outer casing being inserted in a form-fitting manner into the measuring head receptacle for connecting the chip carrier and measuring head. The measuring head can be connected to the chip carrier in a form-fitting and/or non-positive manner, for example with a screw connection, opposite to an insertion direction in which the measuring head is inserted into the measuring head receptacle. For this purpose, the measuring head can have a thread which is designed to correspond in shape to a thread of the measuring head receptacle in order to connect the measuring head and the measuring head receptacle by screwing the threads into one another. The thread can be designed as part of a screw body of the measuring head.

It is advantageous if the chip carrier and the measuring head of the fiber-optic pressure sensor are connected to one another in a fluid-tight manner, in particular in a liquid-tight and/or gas-tight manner. For this purpose, the measuring head can have a sealing element. The sealing element can be formed with, in particular, polytetrafluoroethylene (PTFE). For a robust fluid-tight connection, it is advantageous if the chip carrier and the measuring head are connected to one another in such a way that a press connection between the sealing element and the chip carrier, in particular the measuring head receptacle,

is manufactured. It is advantageous if the sealing element surrounds the measuring head circumferentially or forms a circumference of the measuring head. The sealing element can be part of the outer jacket. It has proven useful if the outer jacket, in particular the sealing element, is designed to be conical at least in sections. It is advantageous if, in an insertion direction in which the measuring head is inserted into the measuring head receptacle, a support element, usually a support ring, is arranged in front of at least one segment of the sealing element, so that the sealing element is pressed against the support element when the measuring head is inserted into the measuring head receptacle becomes. Several such sealing elements can expediently be provided.

[0021] For high measurement accuracy, it is advantageous if the fiber-optic pressure sensor has an optical waveguide, the optical waveguide being coupled to a measuring surface of the fiber-optic pressure sensor, so that a change in a fluid pressure acting on the measuring surface results in a change in an optical signal line, in particular a change an interference signal, a light wave signal coupled into the optical waveguide corresponds to measure the fluid pressure. The change in the optical signal line can be, for example, a change in the optical path length of the light wave signal or a change in an interference signal formed by interference of the light wave signal. The measuring surface can be part of the optical waveguide, in particular a first end piece of the optical waveguide. The first end piece can be designed as part of the measuring head. The measuring surface can be elastically deformable, so that for fluid pressure measurement, the fluid pressure acting on the measuring surface causes an elastic deformation of the measuring surface. For this purpose, the measuring surface can expediently be an elastically deformable membrane. The measuring surface can be coupled to a mirror element, so that an elastic deformation of the measuring surface corresponds to a displacement of the mirror element. For this purpose, an inside of the measuring surface, in particular the membrane, can be a mirror or connected to a mirror. In this way, by displacing the mirror element, an optical path length of a light wave signal reflected on the mirror element can be changed in order to measure the fluid pressure. It is advantageous if the displacement of the mirror causes an interference signal, formed with interference from a light wave signal coupled into the optical waveguide, in order to measure the fluid pressure.

[0022] It is advantageous for high accuracy if the measuring surface and the optical waveguide are coupled to one another via an optical resonator in order to bring about a change in the optical signal line. The optical resonator is usually formed with a plurality of mirrors in order to cause multiple reflections of a light wave signal coupled into the optical waveguide between the mirror elements, so that the light wave signal forms an interference signal in order to measure the fluid pressure by measuring the interference signal. For this purpose, at least one of the mirrors is usually partially transparent to the light wave signal. Another of the mirrors can be the aforementioned mirror element. For example, a partially transparent mirror can be placed in front of the mirror element in the light wave coupling direction into the optical waveguide in order to generate multiple reflections between the mirror element and the partially transparent mirror to form an interference signal. The mirror element can be designed to be completely reflective. It is preferred if the optical resonator is a Fabry-Perot resonator. It is usually provided that the interference signal is returned along the optical waveguide counter to the light wave coupling direction, in particular for detection with a detector.

Light wave coupling direction usually refers to that direction along the optical waveguide in which the light wave signal is coupled into the optical waveguide with a light emission source.

[0024] The fluid pressure can be measured interferometrically, particularly in the manner mentioned above. Preferably, the fiber optic pressure sensor has an interferometer to measure the fluid pressure. For example, the interferometer can be a Fabry-Perot interferometer.

The fiber-optic pressure sensor can have a detector in order to use the detector to detect a change in the optical signal line, in particular a change in an interference signal

to measure the light wave signal coupled into the optical fiber. The detector is usually coupled to a second end piece of the optical waveguide in order to measure a light wave signal, in particular an interference signal, which is conducted via the optical waveguide to the second end piece. The light wave signal is usually directed counter to the light wave coupling direction to the second end piece or detector. The second end piece is usually an end piece of the optical waveguide facing away from the measuring surface. The detector can be, for example, a photodetector. In particular, the detector can be used to measure an optical path length change, in particular the aforementioned one, or an interference signal. The detector is usually connected to an electronic evaluation unit for data transmission. The electronic evaluation unit can be designed for measurement data collection and/or further processing of measurement data.

The fiber-optic pressure sensor usually has a light emission source which is coupled to the optical waveguide in such a way that a light wave signal generated by the light emission source can be coupled into the optical waveguide. For this purpose, the light emission source is usually coupled to a second end piece, in particular the aforementioned second end piece, of the optical waveguide. The light wave signal can be an electromagnetic wave, in particular in the electromagnetic UV wavelength spectrum, in the electromagnetic wavelength spectrum visible to humans, or electromagnetic infrared wavelength spectrum. Accordingly, the optical waveguide is usually designed to transmit such a light wave signal or the detector is designed to detect such a light wave signal. The detector and the light emission source can, for example, be connected to the second end piece of the optical waveguide using an optical coupler, for example an optical splitter.

A compact structure can be implemented if the first end piece of the optical waveguide is designed as part of the measuring head. The measuring head can have a fixing body which is arranged on the first end piece of the optical waveguide, usually by means of a non-positive, positive and/or material connection. The fixing body can surround the first end piece circumferentially, for example in a tubular shape. The sealing element and/or the support element are usually arranged on the fixing body. A robust structure can be achieved if the sealing element is arranged with the support element in a non-positive manner on the fixing body, for example if it is clamped to the fixing body.

For an accurate fluid pressure measurement, it is advantageous if the dead volume of the fluid pressure measurement with the fiber-optic pressure sensor is less than 10 µl, in particular less than 5 µl, preferably less than 1 µl, particularly preferably less than 0.5 µl. The fiber-optic pressure sensor is usually coupled to the microfluid chip or microfluid channel system with such a dead volume for fluid pressure measurement.

It is practical if the chip carrier has an adapter holder that is detachably connected to a chip carrier body of the chip carrier in order to connect the microfluid chip to the chip carrier body by means of the adapter holder. The adapter holder can be designed for a positive and/or non-positive, detachable connection to a microfluid chip. The adapter holder can have a chip holder designed to correspond in shape to a size and/or shape of a microfluid chip, with which the microfluid chip can be connected in a form-fitting and/or force-fitting manner. The chip holder can be designed with a holder frame. The chip receptacle can expediently have a fixing element, in particular releasably connectable to the receiving frame, wherein in order to arrange the microfluid chip on the receiving frame, the microfluid chip can be arranged between the receiving frame and the fixing element, so that the microfluid chip with fastening of the fixing element on the receiving frame is positively and/or non-positively connected to the receiving frame Adapter holder can be connected. A high practicality of use can be achieved if the adapter holder is designed to have a shape corresponding to a shape and/or size of a class of microfluid chips of the same shape and/or size in order to connect different classes of microfluid chips with different adapter holders to the chip carrier body. The holding device can have several adapter holders, with different adapter holders for connecting to different classes

are formed by microfluid chips. A class of microfluidic chips usually defines microfluidic chips of the same shape and/or size. Microfluidic chips of different classes usually have a different shape and/or size.

It is advantageous if the holding device has a plurality of individually controllable, in particular regulatable, heating elements in order to heat the microfluid chip in a controlled, in particular regulated, manner when in use. As a result, a temperature of the microfluid chip or a fluid supplied to the microfluid chip can be adjusted, in particular controlled, preferably regulated. The heating elements are usually arranged in such a way that, when in use, the microfluid chip can be heated with the heating elements from different sides in relation to the microfluid chip. The heating elements are usually arranged in such a way that, when in use, there is a heating element next to the microfluid chip on each side of the microfluid chip, with each side in particular being assigned its own heating element. An arrangement of the heating elements refers in particular to a view orthogonal to the arrangement plane. An arrangement of the heating elements in relation to a microfluid chip in the used state can apply in an analogous manner to an arrangement of the heating elements in relation to the chip carrier. Typically, at least two heating elements are arranged in such a way that they are arranged on opposite sides of the microfluid chip when in use. For this purpose, the at least two heating elements are usually arranged on opposite sides of the chip carrier. The heating elements are usually arranged laterally next to the microfluid chip or the chip carrier in a top view of the arrangement plane. This means that an observation line of sight along which the microfluid chip is usually observed when in use is not obscured. The arrangement plane is usually aligned parallel to a longitudinal extent and width extent of the microfluid chip. The observation line of sight is usually oriented transversely, in particular orthogonally, to the arrangement plane. It is advantageous if several heating elements are arranged circumferentially around the chip carrier in a plan view of the arrangement plane or, when in use, circumferentially around the microfluid chip. Preferably more than three, in particular between three and five, individually controllable, in particular adjustable, heating elements are provided. The heating elements are usually arranged in such a way that the microfluid chip can be heated from a lower side when in use. Alternatively or cumulatively, it can be advantageous if the heating elements are arranged in such a way that the microfluid chip can be heated from an upper side when in use. The heating elements can be designed as electrical resistance heaters. The heating elements are usually plate-shaped, in particular as heating foils. The heating elements can advantageously be designed or arranged to heat the microfluid chip or the fluid to a temperature of more than 100 ° C, in particular more than 130 ° C, preferably between 25 ° C and 200 ° C.

It is advantageous if the holding device has a fan for generating an air flow in order to distribute heat generated by the heating elements with the air flow along the microfluid chip when in use. This allows a homogeneous temperature distribution to be achieved on the microfluid chip or in a fluid supplied to it. It is usually provided that the fan can be individually controlled, in particular regulated. In particular separately from the heating elements. Preferably, several fans are provided, which can each be individually controlled, in particular regulated. In particular, a temperature of the microfluid chip or a fluid supplied to it can be set with high accuracy by individually controllable, in particular regulatable, heating elements and at least one, preferably several, individually controllable, in particular regulable, fans. It is advantageous if the holding device has an electronic control device which is designed to individually control, in particular regulate, the heating elements and/or the fans.

Individual control of the heating elements or fans refers in particular to controlling the heating elements so that a heating intensity of the heating elements can be controlled separately from one another or air acceleration with the fans can be controlled separately from one another. This applies in an analogous manner to regulating the heating elements or fans. This can be done with a common control device or several control devices of the holding device

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be implemented. The chip carrier can expediently have one or more valves which are connected to the fan in an air flow-conducting manner in order to direct an air flow generated by the fan via the valves to the microfluid chip. For this purpose, the valves can be coupled to the fan via air supply lines. For high accuracy, it is advantageous if different valves are coupled to different fans in order to direct air flows generated by different fans via different valves to the microfluid chip. For this purpose, each of the fans is usually assigned at least one valve of its own.

Precise temperature control can be achieved if the holding device has one or more thermocouples in order to carry out control, in particular regulation, of the heating elements and/or the fan depending on a temperature measurement with the thermocouples. The thermocouples are usually arranged laterally next to the chip carrier in a top view of the arrangement plane or, when in use, laterally next to the microfluid chip. Usually, at least two thermocouples are arranged in such a way that they are arranged on opposite sides of the microfluid chip when in use. For this purpose, the at least two heating elements are usually arranged on opposite sides of the chip carrier. At least four thermocouples are preferably provided, which in the operational state are arranged on different sides of the microfluid chip in a top view of the arrangement plane.

The chip carrier can be formed with a holding frame with which the microfluid chip can be connected in a form-fitting and/or force-fitting manner, for example by means of a screw connection and/or clamp connection. The chip carrier can have a fastening element, in particular releasably connectable to the holding frame, wherein in order to arrange the microfluid chip on the holding device, the microfluid chip can be arranged between the holding frame and the fastening element, so that the microfluid chip with fastening of the fastening element on the holding frame is positively and/or non-positively connected to the holding frame Chip carrier can be connected. The fastening element can be a frame structure. In this way, the microfluid chip can be arranged with the chip carrier in the arrangement plane. The microfluid chip can be arranged with the chip carrier on the holding device in such a way that a central region of the microfluid chip is uncovered in the observation direction in order to observe or examine the central region. The observation direction is usually a view from above of the microfluid chip, usually substantially orthogonal to the arrangement direction. Typically, the holding device is designed in such a way that, when in use, the microfluid chip can be irradiated with light, in particular irradiated through it, from an underside, in particular essentially opposite to the observation direction. For this purpose, the holding device can have a light source which can be designed in such a way that a light source can be arranged under the microfluid chip for irradiation, in particular radiation, of the microfluid chip.

An examination arrangement for examining the behavior of a fluid can advantageously be provided, the examination arrangement having a holding device and a microfluid chip, the microfluid chip being arranged on the holding device with a chip carrier, in particular releasably. The holding device and the microfluid chip can be designed as described in this document.

The further object of the invention is achieved by a method of the type mentioned at the outset for using a microfluid chip, in particular for examining the flow behavior of a fluid, when a fluid pressure of the fluid supplied into the microfluid channel system is measured with a fiber-optic pressure sensor and/or the microfluid chip or the fluid is heated with several individually controllable heating elements. The method can in particular be implemented with an aforementioned holding device. With the fiber optic pressure sensor, the fluid pressure in the microfluidic channel system can be determined with high accuracy. The fiber-optic pressure sensor can expediently be connected to the microfluid channel system for fluid pressure measurement. By individually controlling, in particular regulating, the heating elements, a temperature of the microfluid chip or the fluid in the microfluid channel system can be set with high precision. In this way, boundary conditions can be created

Examination of the behavior of the fluid, in particular its flow behavior, can be determined with high precision. Accordingly, studies can be carried out with a high level of information. This is particularly true for simulating or replicating the behavior of a fluid in a rock. Preferably, a channel system, in particular a pore system, of a rock is simulated with the microfluid chip, in particular its microfluid channel system.

[0037] It is understood that the method for using a microfluid chip can be designed in accordance with the features and effects that are described in this document in the context of a holding device, in particular above. The same applies to the holding device with regard to the method.

The fluid can be liquid and/or gaseous. It is advantageous if the fluid is formed with, in particular from, oil, in particular petroleum, and/or with, in particular from, natural gas.

It is advantageous if the microfluid chip is heated with heating elements, an air flow being generated with a fan in order to distribute heat generated by the heating elements along the microfluid chip, with the heating elements being controlled individually and the fan being controlled individually from one another. in particular regulated. In this way, a temperature of the microfluid chip or fluid can be set, in particular controlled, preferably regulated, with high precision. Preferably, the heating elements and the fan are controlled, in particular regulated, depending on a temperature measured with several thermocouples.

Further features, advantages and effects of the invention result from the following illustration of an exemplary embodiment. The drawings to which reference is made show:

1 shows an exploded view of a holding device for holding a microfluid chip in a view from the front;

2 shows a view of the holding device from above;

3 shows a representation of the holding device in an exploded view

a view from behind;

4 shows a representation of a region of a chip carrier of the holding device with a fiber-optic pressure sensor coupled to the chip carrier;

5 to 7 show partial representations of the fiber-optic pressure sensor;

8 is a cross-sectional view of the holding device viewed from below.

1 shows a schematic representation of a holding device 1 for holding a microfluid chip 2 in an exploded view and a microfluid chip 2. The microfluid chip 2 can be detachably arranged, usually fixed, on the holding device 1 with a chip carrier 3. The chip carrier 3 has a holding frame 4 with which the microfluid chip 2 can be connected in a form-fitting and/or force-fitting manner. For this purpose, the chip carrier 3 has a fastening element 5 which can be detachably connected to the holding frame 4 and which can be designed as a frame structure, wherein in order to arrange the microfluid chip 2 on the holding device 1, the microfluid chip 2 can be arranged between the holding frame 4 and the fastening element 5, so that the Microfluid chip 2 with attachment of the fastening element 5 to the holding frame 4 can be connected to the chip carrier 3 in a form-fitting and / or non-positive manner. In this way, the microfluid chip 2 can be arranged with the chip carrier 3 in an imaginary arrangement plane, with a length and a width of the microfluid chip 2 generally being oriented parallel to the arrangement plane. The microfluid chip 2 can be arranged with the chip carrier 3 on the holding device 1, so that a central region of the microfluid chip 2 is uncovered in an observation direction B in order to observe or examine the central region. The observation direction B is usually a view from above onto the microfluid chip 2, usually essentially orthogonal to the arrangement direction. Fig. 2 shows a schematic

matic representation of the holding device 1 of FIG. 1 in a view from above or a view from the observation direction B.

The microfluid chip 2 has a microfluid channel system 8, a fluid inlet 6 and a fluid outlet 7 in order to introduce a fluid into the microfluid channel system 8 via the fluid inlet 6 in the use state and to discharge the fluid from the microfluid channel system 8 via the fluid outlet 7. The microfluid channel system 8 usually corresponds to a channel structure or pore structure of a rock.

3 shows a schematic representation of the holding device 1 of FIG. 1 in an exploded view in a view obliquely from the rear. The holding device 1 has a supply valve 9, so that in the operating state with control, in particular regulation, of the supply valve 9, a supply of fluid to the fluid inlet 6 can be controlled, in particular regulated. The holding device 1 has a discharge valve 10, so that in the operating state with control, in particular regulation, of the discharge valve 10, a discharge of the fluid from the fluid outlet 7 can be controlled, in particular regulated. The holding device can have one or more operating levers 11 with which the supply valve 9 and discharge valve 10 can be controlled, in particular separately from one another. The chip carrier 3 usually has an input connection 12, which in the use state is connected in a fluid-conducting manner to the fluid inlet 6 of the microfluid chip 2 in order to supply fluid to the fluid inlet 6 via the inlet connection 12. This is usually done via a supply channel 13 of the input connection 12, which connects to the fluid inlet 6 in a fluid-conducting manner when in use. The supply valve 9 can be designed to control, in particular regulate, a flow of fluid through the inlet connection 12 when in use. The chip carrier 3 usually has an output connection which, when in use, is connected in a fluid-conducting manner to the fluid outlet 7 of the microfluid chip 2 in order to discharge fluid from the fluid outlet 7 via the output connection. The discharge valve 10 can be designed to control, in particular regulate, a flow of fluid through the output connection when in use.

The holding device has a fiber-optic pressure sensor 14 in order to measure a fluid pressure of the fluid supplied into the microfluid channel system 8 when in use. The fiber-optic pressure sensor has a measuring head 15, having a measuring surface 16, in order to measure a fluid pressure acting on the measuring surface 16. The fiber-optic pressure sensor 14 has an optical waveguide 17, with a first end piece 18 of the optical waveguide 17 being formed as part of the measuring head 15. The measuring head 15 is coupled to the chip carrier 3 in such a way that a fluid supplied via the input connection 12 in the operational state has a fluid pressure-transmitting effect on the measuring surface 16. 4 shows a schematic representation of an area of the chip carrier 3 of FIG. 1, in which the measuring head 15 of the fiber-optic pressure sensor 14 is coupled to the chip carrier 3. The chip carrier 3 has a fluid transfer channel 20, which is connected to the supply channel 13 of the input connection 12 in a fluid-conducting manner. The measuring surface 16 is connected to the fluid transfer channel 20 for fluid pressure measurement. When in use, the supply channel 13 usually connects to the fluid inlet 6 of the microfluid chip 2.

The chip carrier 3 has a measuring head receptacle 21, which is designed to correspond in shape to an outer casing of the measuring head 15, the outer casing being inserted in a form-fitting manner into the measuring head receptacle 21 in order to connect the chip carrier 3 and the measuring head 15. The measuring head 15 has a sealing element 22, which forms part of the outer jacket in order to implement a fluid-tight connection between the measuring head receptacle 21 and the measuring head 15. The sealing element 22 extends circumferentially around the first end piece 18 of the optical waveguide 17 and is conical in sections. It is advantageous if the sealing element 22 is made of polytetrafluoroethylene (PTFE). The measuring head 15 has a tubular fixing body 23, which is arranged on the first end piece 18 of the optical waveguide 17 by means of a non-positive, positive and/or material connection. The fixing body 23 can expediently enclose the first end piece 18 circumferentially. A segment of the sealing element 22 is preceded by a support element 24, usually a support ring, in an insertion direction in which the measuring head 15 is inserted into the measuring head receptacle 21, so that the sealing

element 22 is pressed against the support element 24 in a state of the measuring head 15 inserted into the measuring head receptacle 21. The sealing element 22 and the support element 24 are arranged on the fixing body 23. It is practical if the sealing element 22 is clamped to the fixing body 23 with the support element 24. The measuring head 15 can have a screw body 25 with a thread 26, which is designed to correspond in shape to a thread of the measuring head holder 21, in order to connect the measuring head 15 by screwing the threads into one another.

The first end piece 18 is coupled to the measuring surface 16, so that a fluid pressure acting on the measuring surface 16 or a change in the fluid pressure corresponds to a change in an optical signal line, in particular an interference signal, of a light wave signal coupled into the optical waveguide 17. The measuring surface 16 is preferably designed as an elastically deformable membrane. The measuring surface 16 can be coupled to a mirror element, so that an elastic deformation of the measuring surface 16 corresponds to a displacement of the mirror element. The mirror element is preferably designed as part of a measuring interferometer of the fiber-optic pressure sensor 14, an interference signal being formed with the light wave signal in order to measure the fluid pressure interferometrically, a displacement of the mirror element corresponding to a change in the interference signal. It is usually provided that in order to form the interference signal, multiple reflections of the light wave signal are formed between the mirror element and a mirror in order to generate the interference signal. This can be implemented with a Fabry-Perot resonator. The mirror is usually partially transparent to the light wave signal in order to couple out the interference signal for measurement. Typically, the interference signal is reflected back along the optical waveguide 17 in order to measure the interference signal with a detector, usually a photodetector, which is connected to a second end piece 19 of the optical waveguide 17. The second end piece 19 is usually coupled to a light emission source, usually a laser, for coupling the light wave signal. The detector and the light emission source can be connected to the optical waveguide 17, for example using an optical coupler. In Fig. 5 to Fig. 7, the fiber-optic sensor of the holding device 1 of Fig. 1 is shown in detail.

8 shows a schematic cross-sectional representation of the holding device 1 of FIG. 1 in a view from below. The holding device 1 has a plurality of individually controllable, in particular regulatable, heating elements 27 in order to heat the microfluid chip 2 in a controlled, in particular regulated, manner when in use. The heating elements 27 are arranged in a view orthogonal to the arrangement plane next to the microfluid chip 2, so that the microfluid chip 2 can be heated with the heating elements 27 from different sides in relation to the microfluid chip 2. Preferably, a heating element is present on each side of the microfluid chip 2 next to the microfluid chip 2, with each side in particular being assigned its own heating element. Because the heating elements 27 can be controlled, in particular regulated, individually, i.e. separately from one another, a temperature of the microfluid chip 2 or of the fluid that is supplied to the microfluid channel system 8 can be set with high precision. The holding device 1 can have a fan 28 for generating an air flow in order to distribute heat generated by the heating elements 27 with the air flow along the microfluid chip 2 when in use. This makes it possible to ensure a particularly pronounced homogeneity of a temperature distribution along the microfluid chip 2 or in a fluid supplied to it. The holding device 1 can have one or more thermocouples in order to carry out control, in particular regulation, of the heating elements 27 and/or the fan 28 depending on a temperature measured with the thermocouples.

If the holding device 1 has a fiber-optic pressure sensor 14 for measuring fluid pressure and/or several individually controllable heating elements 27 for heating the microfluid chip 2 or the fluid in the microfluid channel system 8, a pressure and/or a temperature of the fluid in the microfluid channel system 8 can be at high Accuracy can be represented. This allows the behavior, in particular flow behavior, of the fluid to be realistically simulated or recreated and examined. This enables an optimized application of the

Holding device 1 or the microfluid chip 2, in particular for predicting behavior, in particular flow behavior, of fluid in a rock.

Claims (15)

Patent claims 1. Holding device (1) for holding a microfluid chip (2), the holding device (1) having a chip carrier (3) for, in particular releasably, arranging a microfluid chip (2) in order to via a fluid inlet (6) of the microfluid chip (2). to supply a fluid, in particular oil, into a microfluid channel system (8) of the microfluid chip (2), characterized in that the holding device (1) has a fiber-optic pressure sensor (14) in order to detect a fluid pressure of the fluid supplied into the microfluid channel system (8) when in use to measure, and / or the holding device (1) has a plurality of individually controllable heating elements (27) in order to heat the microfluid chip (2) or the fluid in a controlled manner when in use. 2, holding device (1) according to claim 1, characterized in that the fiber-optic pressure sensor (14) is coupled to the chip carrier (3) in such a way that the fiber-optic pressure sensor (14) is connected to the microfluid channel system (8) in the use state in order to to measure a fluid pressure of the fluid supplied into the microfluid channel system (8). 3. Holding device (1) according to claim 1 or 2, characterized in that the chip carrier (3) has a fluid transfer channel (20), which fluid transfer channel (20) in the use state connects to the microfluid channel system (8) of the microfluid chip (2) in a fluid-conducting manner, wherein a measuring surface (16) of the fiber-optic pressure sensor (14) is connected to the fluid transmission channel (20) for measuring the fluid pressure. 4. Holding device (1) according to one of claims 1 to 3, characterized in that the chip carrier (3) and a measuring head (15) of the fiber-optic pressure sensor (14) are connected to one another in a fluid-tight manner. 5. Holding device (1) according to claim 4, characterized in that the measuring head (15) has a sealing element (22), preferably made of polytetrafluoroethylene, in order to connect the chip carrier (3) and the measuring head (15) to one another in a fluid-tight manner. 6. Holding device (1) according to one of claims 1 to 5, characterized in that the chip carrier (3) and a measuring head (15) of the fiber-optic pressure sensor (14) are connected to one another in a form-fitting and / or force-fitting manner. 7. Holding device (1) according to claim 6, characterized in that the chip carrier (3) has a, preferably conical, measuring head receptacle (21) and the measuring head (15) has an outer jacket which corresponds in shape to the measuring head receptacle (21), for connecting chip carriers (3) and measuring head (15) the outer jacket is positively inserted into the measuring head holder (21). 8. Holding device (1) according to one of claims 1 to 7, characterized in that the fiber-optic pressure sensor (14) has an optical waveguide (17), the optical waveguide (17) being coupled to a measuring surface (16) of the fiber-optic pressure sensor (14). is, so that a fluid pressure acting on the measuring surface (16) corresponds to a change in an optical signal line, in particular a change in an interference signal, of a light wave signal coupled into the optical waveguide (17) in order to measure the fluid pressure. 9. Holding device (1) according to claim 8, characterized in that the measuring surface (16) and the optical waveguide (17) are coupled via an optical resonator in order to bring about a change in the optical signal line. 10. Holding device (1) according to one of claims 1 to 9, characterized in that the chip carrier (3) has an adapter holder detachably connected to a chip carrier body of the chip carrier (3) in order to connect the fluid microchip to the chip carrier body by means of the adapter holder, wherein the adapter holder is designed to correspond in shape to a shape and/or size of a class of fluid microchips in order to connect different classes of fluid microchips with different adapter holders to the chip carrier body. 11. Holding device (1) according to one of claims 1 to 10, characterized in that the holding device (1) has a fan (28) for generating an air flow in order to pass heat generated by the heating elements (27) along with the air flow when in use of the microfluid chip (2). 12. Holding device (1) according to one of claims 1 to 11, characterized in that the holding device (1) has one or more thermocouples in order to control, in particular regulation, the heating elements (27) and / or optionally the fan (28). depending on a temperature measurement with the thermocouples. 13. Examination arrangement for examining the behavior of a fluid, the examination arrangement having a holding device (1) and a microfluid chip (2), the microfluid chip (2) being arranged on the holding device (1) with a chip carrier (3), in particular releasably , characterized in that the holding device (1) is designed according to one of claims 1 to 12. 14. A method for using a microfluid chip (2), in particular for examining the flow behavior of a fluid, wherein a microfluid chip (2) on a chip carrier (3) of a holding device (1), in particular a holding device (1) according to one of claims 1 to 13 , is arranged to hold the microfluid chip (2), wherein a fluid, in particular oil, is supplied via a fluid inlet (6) into a microfluid channel system (8) of the microfluid chip (2), characterized in that with a fiber-optic pressure sensor (14). Fluid pressure of the fluid supplied into the microfluid channel system (8) is measured and/or the microfluid chip (2) or the fluid is heated with several individually controllable heating elements (27). 15. The method according to claim 14, characterized in that an air flow is generated with a fan (28) in order to distribute heat generated by the heating elements (27) along the fluid microchip, the heating elements (27) being individual and the fan (28 ) are individually controlled, in particular regulated, by each other. This includes 3 sheets of drawings