KR102479327B1 - Apparatus and method for measuring a temperature of cell - Google Patents

Abstract

An apparatus and method for measuring cell temperature are disclosed. An apparatus for measuring cell temperature according to an embodiment of the present disclosure includes a plurality of end portions and is electrically connected to a Hall element having an Anomalous Hall Effect (AHE) characteristic and a pair of first end portions among the end portions. A current applying unit for applying current to the Hall element, a magnetic field applying unit for applying an external magnetic field in a direction perpendicular to the direction of the current applied to the Hall element, and a pair of end parts connected to the second end part of the end part to form a hole of the Hall element. A signal analysis unit that measures voltage, a temperature table including characteristics of the relationship between Hall voltage and temperature, and a control unit that calculates the temperature of an object directly or indirectly thermally connected to the Hall element based on the current applied to the Hall element and an external magnetic field. can include

Description

Apparatus and method for measuring cell temperature {APPARATUS AND METHOD FOR MEASURING A TEMPERATURE OF CELL}

The present disclosure relates to a cell temperature measuring device and method for measuring the temperature of a cell using magnetic properties of temperature.

Temperature is a fundamental parameter essential for various industrial processes and scientific research, and various methods for measuring it are known.

Various methods have been devised to accurately measure the temperature of an object from the conventional mercury thermometer. For example, a bimetallic thermocouple, a non-contact thermometer using infrared rays, a thermal imaging camera thermometer that combines infrared rays and an image sensor that reacts to them, a thermometer using Raman spectroscopy, a microneedle thermometer, and an infrared imaging thermometer for fluorescent materials. Efforts are being made to measure temperature more accurately with many technologies, such as , liquid crystal phase change thermometers, and scanning probe thermometers using AFM (Atomic Force Microscopy). However, these temperature measuring devices are pointed out as disadvantages, such as restrictions on measurement temperature, area, measurement temperature range, etc., and enlarging equipment, respectively, and are acting as limitations on application.

In particular, countless chemical reactions are involved in maintaining life phenomena in vivo, and temperature is one of the very important factors determining whether or not the reaction proceeds. Moreover, as disclosed in Prior Art 1 (Registered Patent No. 10-1797817), with the recent development of medical high-intensity ultrasound treatment technology and thermal treatment technology, local sites in vivo, for example, nanoscale, such as single cell level Interest in technology for monitoring temperature changes is growing.

In the field of measuring cell temperature, most of the technologies using fluorescent materials are applied and used, but they have many problems, such as limitations in resolution and limitations on the duration of fluorescent materials. In addition, since it is difficult to reuse a sensor that is measured once due to the characteristics of a bio experiment that is sensitive to contamination, there is a problem in that an expensive sensor must be replaced for each measurement.

In addition, the infrared thermal imaging method directly measures infrared rays emitted according to the temperature of cells, and obtains a thermal image using an infrared image sensor or the like. However, since the method through infrared thermal imaging is more affected by the surrounding environment than the measurement object, it is difficult to accurately measure the temperature of the object. this exists

The foregoing background art is technical information that the inventor possessed for derivation of the present invention or acquired during the derivation process of the present invention, and cannot necessarily be said to be known art disclosed to the general public prior to filing the present invention.

Prior art 1: Korean Patent Registration No. 10-1797817 (registered on November 8, 2017)

An object of an embodiment of the present disclosure is to efficiently measure the temperature of a cell using a temperature-dependent magnetic characteristic based on the Anomalous Hall Effect (AHE) with only a very small amount of a test object.

An object of an embodiment of the present disclosure is to reduce the Curie temperature of the Hall element and measure the temperature change amount by the cell connected to the Hall element and heat conduction with the Hall voltage change, so that the temperature of the cell going up to the Hall element can be directly measured. there is.

An object of an embodiment of the present disclosure is to prevent a temperature rise of the Hall element itself, so that the temperature of a cell can be measured stably, accurately and precisely.

An object of an embodiment of the present disclosure is to form a Hall element in a pattern using lithography, so that a nano- or micro-sized subminiature thermometer can be manufactured.

The purpose of the embodiments of the present disclosure is not limited to the above-mentioned tasks, and other objects and advantages of the present invention not mentioned above can be understood by the following description and will be more clearly understood by the embodiments of the present invention. will be. It will also be seen that the objects and advantages of the present invention may be realized by means of the instrumentalities and combinations indicated in the claims.

An apparatus for measuring cell temperature according to an embodiment of the present disclosure may perform micro-measurement of a single cell using magnetic characteristics for temperature based on the Anomalous Hall Effect (AHE).

Specifically, the device for measuring cell temperature according to an embodiment of the present disclosure includes a plurality of end portions and electrically connects a Hall element having an abnormal Hall effect characteristic and a pair of first end portions among the end portions to generate current to the Hall element. A signal for measuring the Hall voltage of the Hall element connected to a current supply unit for applying a voltage, a magnetic field application unit for applying an external magnetic field in a direction perpendicular to the direction of the current applied to the Hall element, and a pair of second end parts among the end parts It may include an analyzer, a temperature table including a relationship between Hall voltage and temperature, and a control unit that calculates the temperature of an object directly or indirectly thermally connected to the Hall element based on the current applied to the Hall element and the external magnetic field. .

Through the cell temperature measuring device according to an embodiment of the present disclosure, the temperature of the cell rising to the Hall element can be measured directly by reducing the Curie temperature of the Hall element and measuring the amount of temperature change by the cell connected to the Hall element and heat conduction by the Hall voltage change. It is possible to improve the accuracy of the measurement result by allowing it to be measured.

In addition to this, another method for implementing the present invention, another system, and a computer-readable recording medium storing a computer program for executing the method may be further provided.

Other aspects, features and advantages other than those described above will become apparent from the following drawings, claims and detailed description of the invention.

According to an embodiment of the present disclosure, the performance and reliability of a cell temperature measurement device can be improved by enabling the temperature of a cell to be accurately measured using the magnetic characteristics for temperature based on the Anomalous Hall Effect (AHE) can make it

In addition, by reducing the Curie temperature of the Hall element and measuring the amount of temperature change by the cells connected to the Hall element and heat conduction with the change in Hall voltage, the temperature of the cell going up to the Hall element can be directly measured, so that stable and accurate temperature measurement is possible. can make it possible.

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In addition, by reducing the read current of the Hall element or preventing the temperature rise of the Hall element itself through the cooling function of the electromagnet, failure of the Hall element can be prevented and stability of the cell temperature measuring device can be improved.

In addition, by forming a Hall element in a pattern using lithography, it is possible to manufacture a nano- or micro-sized subminiature thermometer, thereby improving the industrial applicability of the portable cell temperature measuring device.

In addition, the temperature measurement accuracy of a single cell can be improved by being connected to the cell by heat conduction so that the cell temperature change due to the biological activity inside the cell can be directly measured.

In addition, product satisfaction and reliability of the cell temperature measuring device may be improved by forming the entire structure of the cell temperature measuring device to be waterproof and to protect cells from toxicity.

The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

1(a) and 1(b) are views for explaining that a Curie temperature and a saturation magnetization value are functions of temperature according to an embodiment of the present disclosure.
2 is a diagram for explaining a relationship between the ideal Hall effect, a magnetic field, and temperature according to an exemplary embodiment of the present disclosure.
3(a) and 3(b) are diagrams for explaining the ideal Hall effect and temperature for a magnetic alloy according to an embodiment of the present disclosure.
4 is an exemplary diagram schematically illustrating a cell temperature measuring device according to an embodiment of the present disclosure.
5 is a diagram for explaining a heat conduction connection between a Hall element and an object according to an embodiment of the present disclosure.
6 is a schematic block diagram of an apparatus for measuring cell temperature according to an embodiment of the present disclosure.
7 is a block diagram including a schematic structure of a cell temperature measuring device according to an embodiment of the present disclosure.
8 is a block diagram showing a schematic structure of a temperature measuring unit of a cell temperature measuring device according to an embodiment of the present disclosure.
9 is an exemplary view showing a schematic structure of a cell temperature measuring device according to an embodiment of the present disclosure.
10 is a diagram for explaining a signal analysis result of a cell temperature measuring device according to an embodiment of the present disclosure.
11 is an exemplary view showing a signal analysis result of a cell temperature measuring device according to an embodiment of the present disclosure.
12 is a flowchart illustrating a temperature measurement method of a cell temperature measurement device according to an embodiment of the present disclosure.

Advantages and features of the present invention, and methods for achieving them will become clear with reference to the detailed description of embodiments in conjunction with the accompanying drawings.

However, it should be understood that the present invention is not limited to the embodiments presented below, but may be implemented in a variety of different forms, and includes all conversions, equivalents, and substitutes included in the spirit and scope of the present invention. . The embodiments presented below are provided to complete the disclosure of the present invention and to fully inform those skilled in the art of the scope of the invention to which the present invention belongs. In describing the present invention, if it is determined that a detailed description of related known technologies may obscure the gist of the present invention, the detailed description will be omitted.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms include or have are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features, numbers, or steps However, it should be understood that it does not preclude the possibility of existence or addition of operations, components, parts, or combinations thereof. Terms such as first and second may be used to describe various components, but components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In the description with reference to the accompanying drawings, the same or corresponding components are assigned the same reference numerals, and overlapping descriptions thereof are omitted. I'm going to do it.

1(a) and 1(b) are diagrams for explaining that the Curie temperature and the saturation magnetization value are functions of temperature according to an embodiment of the present disclosure, and FIG. 2 is a two-dimensional hole according to an embodiment of the present disclosure. 3(a) and 3(b) are diagrams for explaining the extraordinary Hall effect and temperature for a magnetic alloy according to an embodiment of the present disclosure.

First, this embodiment relates to measuring the temperature of an object whose temperature is to be measured using that a Curie temperature, which is one of the characteristics of a magnetic material, and a saturation magnetization value are a function of temperature. In this embodiment, it is described that the temperature of a cell can be measured using a cell as an example of an object, but the temperature of another object may be measured according to embodiments without being limited thereto.

As shown in FIG. 1(a), the vertical axis represents the intensity of saturation magnetization of the magnetic material, the horizontal axis represents the ratio between the temperature of the magnetic material and the Curie temperature (Tc), and 1 on the vertical axis represents the magnetization of the magnetic material. When is maximum, 1 on the abscissa axis may mean the Curie temperature of the magnetic material. That is, referring to FIG. 1(a), it can be seen that the saturation magnetization value of a magnetic material rapidly decreases as it approaches the Curie temperature, and magnetization is lost above the Curie temperature.

Here, the Curie temperature is also referred to as the Curie temperature or the Curie point, and means the temperature when the phase transitions from a ferromagnetism state to a paramagnetism state. That is, when a paramagnetic substance is heated above a certain temperature, it loses its properties as a magnet and becomes a paramagnetic substance. At the Curie temperature, a large specific heat usually appears and has little to do with pressure. In other words, a ferromagnet has a maximum magnetization at a Curie temperature of 0 K, and there exists a situation where all spins can align, but as the temperature continues to rise, more and more parallel alignments become disordered by thermal motion, just below the Curie temperature. At , the alignment is rapidly broken, and above the Curie temperature, the alignment disappears altogether.

In general, the Curie temperature of magnetite is 575 °C, hematite is 675 °C, pure iron is 770 °C, nickel is 358 °C, and cobalt is 1131 °C. In this embodiment, the temperature of the cell is measured below the Curie temperature at which the ferromagnetic state of the magnetic material is maintained, and the Curie temperature needs to be reduced to room temperature, which is the temperature of the cell.

1 (b) is a diagram showing the Curie temperature according to the decrease in the thickness of a magnetic material, in particular, as shown in FIG. 0.6 nm), it can be seen that the Curie temperature can be reduced to about 400 K.

However, in this embodiment, since the temperature of the cell needs to be measured, it is necessary to further reduce the Curie temperature to room temperature, which is the temperature of the cell. Accordingly, in this embodiment, the Curie temperature can be reduced to about 300 K by using a magnetic alloy in which a common metal (eg, Cu) is added to a pure magnetic material (eg, Co). A more detailed description will be given later.

In this embodiment, based on the fact that the magnitude of the anomalous Hall effect expressed in a ferromagnetic material is proportional to the magnetization amount of the ferromagnetic material, since the magnetization amount of the ferromagnetic material is a function of temperature, the magnitude of the anomalous Hall effect is a function of temperature The temperature of an object (ie, a cell) whose temperature is to be measured can be measured using the temperature sensor. That is, the present embodiment relates to measuring the temperature of a cell through an element made of a magnetic material, that is, a ferromagnetic material, and such an element will be collectively referred to as a Hall element (110 in FIG. 7 ).

In this embodiment, the hall effect according to the external magnetic field for each temperature was measured using a sample of the Hall element 110 composed of substrate/platinum (Pt)/Co/Pt. 2 is a diagram for explaining a relationship between the ideal Hall effect, a magnetic field, and temperature according to an exemplary embodiment of the present disclosure. Referring to FIG. 2 , for example, when the ferromagnetic layer Co of the Hall element 110 is 0.4 nm thick, the relationship between the size of the extraordinary Hall effect, the size of the external magnetic field, and the temperature can be confirmed.

Here, a ferromagnetic material means a material that is strongly magnetized in the direction of the magnetic field when a strong magnetic field is applied from the outside and remains magnetized even when the external magnetic field disappears. means motion. In general, when a magnetic field is applied from the outside in a state in which a current flows through a conductor or semiconductor material, electrons are bent by the Lorentz force and charges are accumulated at the material interface, which is called the Hall effect. That is, the abnormal Hall effect is a phenomenon that occurs in ferromagnetic materials, and conduction electrons undergo spin-dependent scattering by spin orbit coupling, and at this time, depending on the spin state of electrons The direction of scattering is different, so spin-up on one side and spin-down on the other side accumulate, resulting in the Hall effect.

)가 0.4 nm 두께일 때, 강자성 레이어의 합금 조성 비율에 따라 큐리 온도가 달라질 수 있음을 알 수 있다. 본 실시 예에서는, 합금 조성 비율이, 예컨대

일 때, 세포의 온도 범위에서의 온도의 변화가 다양하므로 이러한 조성 비율이 적용될 수 있다. 여기서 세포의 온도 범위는 도 3(a)의 그래프에서 기울기가 급격하게 달라지는 변곡점으로부터의 일정 범위일 수 있으나, 이에 한정되는 것은 아니다. 즉 본 실시 예에서, 홀 소자(110)는 세포의 온도 범위 중 최대값 이상의 큐리 온도를 가질 수 있으며, 이러한 큐리 온도에 해당하는 비율로 합금이 조성될 수 있다. 예컨대 본 실시 예에서, 홀 소자(110)는 300 K 내지 450 K의 큐리 온도를 가질 수 있다.Meanwhile, in this embodiment, as shown in FIG. 3(a), the abnormal Hall effect and temperature were measured using a sample of the Hall element 110 composed of substrate/Pt/CoCu/Pt. Referring to FIG. 3(a), for example, the ferromagnetic layer of the Hall element 110 (

) is 0.4 nm thick, it can be seen that the Curie temperature can vary depending on the alloy composition ratio of the ferromagnetic layer. In this embodiment, the alloy composition ratio is, for example

When , this composition ratio can be applied because the change in temperature in the temperature range of the cell varies. Here, the temperature range of the cell may be a certain range from the inflection point at which the slope rapidly changes in the graph of FIG. 3 (a), but is not limited thereto. That is, in this embodiment, the Hall element 110 may have a Curie temperature equal to or higher than the maximum value in the cell temperature range, and an alloy may be formed at a ratio corresponding to the Curie temperature. For example, in this embodiment, the Hall element 110 may have a Curie temperature of 300 K to 450 K.

/Pt로 구성된 홀 소자(110)의 샘플을 이용하여 온도 변화에 따른 이상 홀 효과의 비율을 측정하였다. 도 3(b)를 참조하면, 순수 Co 일 때보다

일 때, 온도 변화에 따른 이상 홀 효과의 비율, 즉 홀 저항의 변화가 커서 세포의 온도를 측정하기 용이함을 알 수 있다.Also, in this embodiment, as shown in FIG. 3(b), Ta/Pt/Co/Pt or Ta/Pt/

The ratio of the abnormal Hall effect according to the temperature change was measured using a sample of the Hall element 110 composed of /Pt. Referring to Figure 3 (b), than when pure Co

When , it can be seen that the ratio of the anomalous Hall effect according to the temperature change, that is, the change in Hall resistance is large, and it is easy to measure the temperature of the cell.

Meanwhile, in the present embodiment, a desired measurement range of the cell temperature can be set by replacing the magnetic alloy of cobalt and copper with another ferromagnetic material having perpendicular magnetic anisotropy.

4 is an exemplary view schematically illustrating a cell temperature measuring device according to an embodiment of the present disclosure, and FIG. 5 is a diagram for explaining heat conduction connection between a Hall element and an object according to an embodiment of the present disclosure.

As shown in FIG. 4, in this embodiment, cells (or culture medium, blood, etc.) are placed on the Hall element 110, and based on the Hall voltage of the Hall element 110, the Hall element 110 and It relates to directly or indirectly calculating the temperature of a cell connected to heat conduction. At this time, the structure of the Hall element 110 may be implemented in various forms, but in this embodiment, it may be implemented in a cross shape.

In FIG. 4, the Hall element 110 is shown in the form of a thick rod to explain the cross-shaped structure, but as shown in FIG. 8 described later, a thin semiconductor piece is attached or applied on the substrate. It would be desirable to be That is, in the present embodiment, the Hall element 110 may be a thin film having a large Hall coefficient and mobility, and may be formed in a cross-shaped structure, making it easier to manufacture thinly.

In this embodiment, as shown in FIG. 5 , when cells immersed in a liquid are placed on a sample made of a substrate, platinum, and silicon oxide, heat flow that changes over time is simulated. At this time, the initial temperature of the cell was set to 312.5 K, the initial temperature of the liquid to 310 K, and the initial temperature of the substrate to 300 K. As a result of the simulation, the temperature of the substrate surface after 100 μs was output as 306.43 K. That is, referring to FIG. 5 , it can be seen that the temperature of the Hall element 110 changes according to the temperature of the cell placed on the Hall element 110 . At this time, since the thermal equilibrium is adjusted to the side having a large heat capacity, the more the size of the Hall element 110 is reduced compared to the cell, the more accurate temperature measurement will be possible. That is, in this embodiment, the width of the Hall element 110 can be reduced to several tens of nm.

On the other hand, in this embodiment, the Hall element 110 has an Anomalous Hall Effect (AHE) characteristic, has a cross shape formed on a substrate, and one of the ends of the cross shape facing each other It may be configured to apply a current through the pair and measure a voltage through the other pair facing each other. At this time, by passing the magnetic flux in a direction perpendicular to the current applied to the Hall element 110, the charge is deflected to the side by the Lorentz Force, and a voltage is generated at the ends other than the pair of ends to which the current is applied. will do Each Hall element 110 may have a small variation in temperature characteristics due to process reasons, but since the temperature characteristic of the Hall element 110 itself does not change, the temperature characteristic of the Hall element 110 is used to conduct heat conduction with cells. The temperature of the cell can be known by measuring the temperature of the Hall element 110 .

In this embodiment, the Hall element 110 may include a plurality of layers, and the plurality of layers are formed on a first non-magnetic layer, the first layer, and a magnetic field applying unit (300 in FIG. 6) It may include a second layer having ferromagnetism in which an extraordinary Hall effect is generated by a magnetic field applied therefrom, and a third layer having non-magnetism formed on the upper side of the second layer.

In addition, a plurality of layers of the Hall element 110 may be formed on a substrate, and therefore, the substrate may also be included in the Hall element 110 .

A first layer may be formed on the substrate. The first layer may be in a polycrystalline state and may induce stress at an interface with the second layer. In addition, the first layer may induce perpendicular magnetic anisotropy at the interface portion of the second layer by magnetic interaction at the interface with the second layer. For example, the first layer may be a heavy metal such as Pt or Pd.

Also, in this embodiment, a buffer layer for facilitating formation of the first layer may be provided between the substrate and the first layer. That is, when the first layer is directly formed on a substrate made of an insulating material, a polycrystalline structure may not be formed because the first layer does not have a constant lattice constant or does not form crystal grains. Therefore, through the formation of the buffer layer, the first layer can be easily formed in a polycrystalline state. For example, the buffer layer may be Ta, Ru or Ti.

The second layer is a ferromagnetic layer, and may have an easy axis of magnetization in a direction perpendicular to the interface due to perpendicular magnetic anisotropy induced at an interface in contact with the first layer or the third layer. In this case, in the bulk region in the second layer, vertical magnetic anisotropy and horizontal magnetic anisotropy may be mixed. That is, vertical magnetization and horizontal magnetization may be mixed, and magnetization in an intermediate region between vertical and horizontal may also appear. However, the lower region and the upper region of the second layer are adjacent to or in contact with the first layer and the third layer, and perpendicular magnetic anisotropy is predominant in the vicinity of the contact region. The strong perpendicular magnetic anisotropy at the interface can induce spin-orbit interaction up to the bulk region.

The perpendicular magnetization of the second layer may be set to the easy axis of magnetization by the spin-orbit interaction. Accordingly, when a magnetic field is applied in a direction perpendicular to the second layer, since the vertical direction becomes an easy magnetization axis, the perpendicular magnetic anisotropy of the second layer is enhanced in proportion to the strength of the applied magnetic field, which may appear as a Hall voltage. .

In this embodiment, the thickness of the second layer may be 0.4 nm to 1.0 nm, and any one of Co, Fe, Ni, CoFe, and CoNi and any one of Cu, Ti, Al, and Ru may be combined as an alloy. there is. For example, in this embodiment, the second layer may include CoCu.

That is, the second layer may include a ferromagnetic magnetic alloy having perpendicular magnetic anisotropy by combining at least two metals, and the Hall element 110 may have different Curie temperatures depending on the composition ratio of the magnetic alloy of the second layer. can have

The second layer may have a thickness of 0.4 nm to 1.0 nm for perpendicular magnetic anisotropy. This means that if the thickness of the second layer is less than 0.4 nm, the second layer may not be formed as a uniform film and may form an island shape on the first layer, and if the thickness of the second layer exceeds 1.0 nm, a problem may occur. This is because the perpendicular magnetic anisotropy of the second layer may not be secured.

When a current flows through the Hall element 110, spin-orbit coupling may occur in the first layer. Spin electrons with the same spin can be concentrated in a specific direction by spin-orbit coupling. Also, in the second layer formed on the first layer, rotational force may be applied to the magnetization of the ferromagnetic material. This may be referred to as spin orbital torque. That is, a phenomenon in which magnetization is aligned in a specific direction may occur in the second layer under the influence of the direction in which current is applied by the spin orbit torque.

In addition, when a magnetic field is applied in a direction parallel to the surface of the second layer and perpendicular to the applied current, gradual reversal of magnetization may be induced in the second layer, and the magnetic domain walls may be moved according to the number of times the pulse current is applied. can The area of the ferromagnetic layer of the second layer having perpendicular magnetic anisotropy is enlarged by the movement of the magnetic domain wall, which increases the extraordinary Hall effect and generates a Hall voltage in the Hall element 110 . When the movement of the magnetic domain walls due to the magnetization reversal occurs in the crossing region of the cross-shaped structure of the Hall element 110, the Hall voltage may increase or decrease according to the movement of the magnetic domain walls.

A third layer may be formed on the second layer. For example, the third layer may be a heavy metal such as Pt or Pd. The third layer may induce perpendicular magnetic anisotropy to the interface of the second layer below. An easy axis of magnetization of the second layer may be determined in a vertical direction by the induced perpendicular magnetic anisotropy. The third layer may be made of the same material as the first layer in order to secure self-symmetry. Also, the thickness of the third layer may be the same as that of the first layer. Through this, magnetic symmetry can be secured, axes of easy magnetization in the bulk region of the second layer can be symmetrically set, and an offset of a Hall voltage, which is an output voltage of the Hall device 110 to be manufactured, can be minimized.

Meanwhile, the plurality of layers of the Hall element 110 may be formed using sputtering, molecular beam deposition (MBE), metal organic chemical vapor deposition (MOCVD) or an electroplating method, and a photosensitive material is applied to the substrate and It may be formed by patterning through lithography of exposure and development using a mask.

6 is a schematic block diagram of a cell temperature measuring device according to an embodiment of the present disclosure, and FIG. 7 is a block diagram including a schematic structure of the cell temperature measuring device according to an embodiment of the present disclosure. 8 is a block diagram showing a schematic structure of a temperature measuring unit of a cell temperature measuring device according to an embodiment of the present disclosure, and FIG. 9 is an exemplary diagram showing a schematic structure of a cell temperature measuring device according to an embodiment of the present disclosure. 10 is a diagram for explaining a signal analysis result of a cell temperature measuring device according to an embodiment of the present disclosure, and FIG. 11 is an example showing a signal analysis result of a cell temperature measuring device according to an embodiment of the present disclosure. It is also

In this embodiment, cell temperature can be measured using the above-described characteristics of the Hall element 110, and the cell temperature measuring device 1 through the Hall element 110 will be described in more detail.

As shown in FIG. 6 , the cell temperature measuring device 1 includes a temperature measurement unit 100, a current application unit 200, a magnetic field application unit 300, a signal analysis unit 400, and a control unit 500. can do.

Referring also to the drawing shown in FIG. 7 , in the cell temperature measuring device 1, the temperature measuring unit 100 may include a Hall element 110, an electrode pad 120, and a microwell plate 130, , The magnetic field application unit 300 may include an electromagnet unit 310 and a power supply unit 320 .

The temperature measuring unit 100 is for measuring the temperature of cells, and includes a micro-well plate 130 on which cells are placed and located above the Hall element 110, and a Hall element 110 having an ideal Hall effect characteristic. and an electrode pad 120 electrically connected to the Hall element 110 so that a current may be applied to the Hall element 110 or a voltage of the Hall element 110 may be measured. In this embodiment, the Hall element 110 may be attached to the lower side of the micro-well plate 130, but is not limited thereto. In addition, in this embodiment, a hole may be provided at a position where the micro-well plate 130 and the center of the Hall element 110 come into contact so that the cells and the Hall element 110 are directly thermally conductively connected. It is not limited to this.

As shown in FIG. 7 , the Hall element 110 may have a cross-shaped structure including a plurality of end portions. However, in this embodiment, the Hall element 110 is lithographically patterned on a substrate, specifically as shown in FIG. 8, so that two linear Hall bars having the same width cross each other at the intersection point. structure, the plurality of end portions may be located at each end of the two Hall bars, and at least a portion of the plurality of end portions may have a shape in which the width increases as the distance from the intersection point increases. A Hall voltage according to a change in perpendicular magnetic anisotropy may be generated at an intersection point where the linear Hall bars of the Hall element 110 intersect. Also, the plurality of end portions may have a kite shape, and the material of the linear hole bar and the plurality of end portions may be the same.

Here, the substrate has a rectangular shape, and the plurality of end portions of the Hall element 110 and the plurality of electrode pads 120 may be positioned at corners of the substrate. In addition, the substrate is preferably made of an insulating material, and may include silicon oxide or silicon nitride, glass, or the like. In addition, any substrate may be used as long as it is an insulating material whose physical properties do not significantly change even in the progress of subsequent processes.

Meanwhile, FIG. 8 is an exemplary view of a mask design for the temperature measuring unit 100. In this embodiment, the temperature measuring unit 100 has a linear Hall bar width of 5 um and a total of Hall elements 110 up to the distal end. The length can be 20 mm, the size of each electrode pad is 2.9 mm X 2.9 mm, the size of the water hole is 5 mm in diameter, and the size of the substrate is 18 mm. However, the above numerical values are not limited and may be changed according to embodiments.

The electrode pad 120 may be configured to be electrically connected to each distal end of the Hall element 110, and the first electrode pad 121, the second electrode pad 122, the third electrode pad 123 and 4 electrode pads 124 may be included.

That is, the electrode pad 120 includes a pair of current terminals 121 and 123 for inputting an alternating current to the Hall element 110 and providing a current movement path, and an alternating voltage that is an output signal of the sensor for a change in magnetic field. It may be configured to include a pair of voltage terminals (122, 124) for measuring. The pair of current terminals 121 and 123 may be provided so that the two current terminals face each other, and the pair of voltage terminals 122 and 124 may also be provided such that the two voltage terminals face each other.

Therefore, the current terminals 121 and 123 are connected to an external current source (eg, a current supply unit) to input current to the Hall element 110, and the voltage terminals 122 and 124 are connected to an external voltage measuring device (eg, a signal It is connected to the analyzer) to output the potential difference between the two voltage terminals.

In this embodiment, the shape of the electrode pad 120 is not limited, such as a form covering each end of the Hall element 110 or a form physically extended to some layers of the Hall element 110, and It may be implemented as a separate metal that is in contact and electrically connected, and in terms of minimizing contact resistance and sheet resistance, it may be preferable to use a non-magnetic metal material having a low resistivity. Also, according to embodiments, the electrode pads 120 may be formed together in the production stage of the Hall element 110, but may be brought into contact only when the cell temperature is to be measured.

That is, in the present embodiment, the temperature measurement unit 100 may decrease the Hall voltage when the temperature of the cell increases compared to the initial temperature based on the hall effect characteristics of the Hall element 110, and the temperature measurement unit 100 In this change of Hall voltage can be measured.

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중 적어도 하나를 포함할 수 있다.Also, as shown in FIG. 8 , the Hall element 110 may include a passivation layer that protects at least a part or all of the Hall element 110 . This protective layer is for waterproofing the Hall element 110 and preventing cell toxicity.

and

may include at least one of them.

The current applying unit 200 may be electrically connected to a pair of first end portions among end portions of the Hall element 110 to apply current to the Hall element 110 . Here, the first end part may be an end part corresponding to the first electrode pad 121 and the third electrode pad 123 among the electrode pads 120 described above. In this embodiment, current may be applied to the distal end corresponding to the third electrode pad 123 and directed toward the distal end corresponding to the first electrode pad 121 .

Accordingly, a Hall voltage may be generated between the end portions corresponding to the second electrode pad 122 and the fourth electrode pad 124 . In addition, spin-orbit coupling is generated in the Hall element 110 by the applied current, and magnetization torque is generated by the spin-orbit coupling, which can cause spin-orbit torque. Further, the magnetic domain wall of the Hall element 110 may move toward the distal end of the position corresponding to the first electrode pad 121 by the spin orbit torque. However, since the movement of the magnetic domain wall may not be smooth only with the applied current, an external magnetic field (eg, a magnetic field applying unit) is applied in a direction parallel to and perpendicular to the surface of the Hall element 110 to enhance the movement of the magnetic domain wall. may be authorized. Movement of the magnetic domain walls within the Hall element 110 may be enhanced by the application of an external magnetic field.

That is, the magnetic field applying unit 300 may apply an external magnetic field in a direction perpendicular to the direction of the current applied to the Hall element 110 . As shown in FIG. 9 , the magnetic field applying unit 300 may include an electromagnet unit 310 including a coil to which current is applied and a cooling unit 330 cooling the coil. Therefore, in this embodiment, the electromagnet unit 310 may be implemented with a waterproof material.

In addition, the magnetic field application unit 300 may include a power supply unit 320, and the power supply unit 320 may be a power supply device for supplying current to the electromagnet unit 310. In this embodiment, it may be controlled by the control unit 500, but is not limited thereto and may be provided separately.

Meanwhile, the movement of the magnetic domain wall can occur only between the distal end corresponding to the third electrode pad 123 and the distal end corresponding to the first electrode pad 121 in the cross-shaped Hall element 110 . That is, the magnetic domain walls do not move toward the other pair of distal ends. This may be due to the fact that the applied current flows between the distal end corresponding to the third electrode pad 123 and the distal end corresponding to the first electrode pad 121 . That is, the area where the spin-orbit torque is generated by the current flowing through the Hall element 110 is the distal end corresponding to the bar-shaped third electrode pad 123 and the distal end corresponding to the first electrode pad 121. is the area occupied by , and in particular, the movement of the magnetic domain walls according to the reversal of magnetization occurring at the crossing point can have a great effect on the change of the Hall voltage. In addition, the abnormal Hall effect may be intensified and the Hall voltage may increase due to the movement of the magnetic domain walls, which are strengthened according to the application of an external magnetic field.

Magnetization in a specific direction within the Hall element 110 may serve as an external magnetic field. Electrons flowing between the distal end corresponding to the third electrode pad 123 and the distal end corresponding to the first electrode pad 121 have up spin and down spin formed at the same ratio, but the Hall element 110 When flowing through the inside, the up spin and down spin are affected by the magnetic moment of the Hall element 110, and accordingly, the electrons with up spin and the electrons with down spin correspond to the side of the Hall element 110 of the cross-shaped structure The distal end at a position corresponding to the second electrode pad 122 and the distal end at a position corresponding to the fourth electrode pad 124 may be deflected.

In addition, spin electrons moving between the end portion corresponding to the third electrode pad 123 of the Hall element 110 and the end portion corresponding to the first electrode pad 121 are ferromagnetic impurities (spin orbital coupling). material), scattering (skew scattering) occurs, and the direction of scattering may appear differently depending on the spin direction of electrons. If the Hall element 110 does not have perpendicular magnetic anisotropy and has a random magnetic moment, scattering of spin electrons is also randomly generated so that no Hall voltage is generated. However, when the Hall element 110 has perpendicular magnetic anisotropy through the movement of the magnetic domain walls, since the impurity itself is ferromagnetic, the degree of scattering according to the spin of electrons is different due to spin dependent scattering. The amount of electrons moving between the distal end corresponding to the electrode pad 122 and the distal end corresponding to the fourth electrode pad 124 is different, and Hall voltage is generated. Through this, the ideal Hall effect can be obtained.

That is, the signal analyzer 400 may measure the Hall voltage of the Hall element 110 by being connected to a pair of second end parts among the plurality of end parts. The second distal end portion may indicate an end portion corresponding to the second electrode pad 122 and an end portion corresponding to the fourth electrode pad 124 .

The signal analyzer 400 may include a lock-in amplifier that is connected to the second terminal and measures the Hall voltage of the Hall element 110 . That is, in this embodiment, the amplitude and phase of a signal related to a designated reference signal can be measured through the lock-in amplifier, and the Hall voltage according to the cell temperature can be precisely measured. In addition, in this embodiment, AC current may be supplied to the coil to which the current of the magnetic field applying unit 300 is applied in synchronization with the reference signal supplied from the lock-in amplifier. Therefore, in this embodiment, the signal-to-noise ratio (SNR) of the measurement result can be increased.

On the other hand, in this embodiment, if the read current is large, the temperature of the Hall element 110 itself may rise due to problems such as Joule heat generation, so it is necessary to reduce the read current.

The controller 500 calculates the temperature of a cell directly or indirectly connected to the Hall element 110 by heat conduction based on a temperature table including a relationship between Hall voltage and temperature, a current applied to the Hall element 110, and an external magnetic field. can do. That is, the controller 500 can calculate the temperature of the cell based on the change in Hall voltage before the cells are heat-conductively connected to the Hall element 110 and after the cells are heat-conductively connected to the Hall element 110 .

In this case, in this embodiment, the change in Hall voltage may be based on the change in magnetization value of the Hall element 110 connected to the cell by thermal conduction. In addition, the temperature table may be set based on the inverse proportionality between the magnetization value and Curie temperature of the Hall element 110 and the proportional characteristic between the Hall voltage and magnetization value of the Hall element 110, and may be stored in a memory (not shown). can

In other words, the controller 500 may calculate the cell temperature based on the Hall voltage using a formula, or may calculate the cell temperature based on the Hall voltage by converting the cell temperature into a numerical table and comparing them.

As shown in FIG. 10 , in this embodiment, when the stack of the Hall elements 110 is Ta/Pt/Co/Pt, the Hall voltage according to the temperature difference of the Hall elements 110 is measured. That is, in this embodiment, it can be seen that the Hall voltage difference decreases as the temperature of the Hall element 110 increases, and the Hall voltage according to the temperature of the Hall element 110 can be stored as a temperature table. Accordingly, the controller 500 can calculate the temperature of the cell based on this.

11 shows the results output through the lock-in amplifier. In this embodiment, when the stack of Hall elements 110 is Ta(3)/Pt(5)/Co(0.6)/Pt(5) The Hall voltage of was measured. In addition, in this embodiment, FIG. 11 shows Hall voltage measurement results when the frequency is 0.1 Hz, the maximum current applied to the electromagnet is 4 A, and the read current is 0.1 mA.

That is, in the present embodiment, the controller 500 may calculate the cell temperature through the Hall voltage measurement result based on the settings shown in FIG. 11 .

12 is a flowchart illustrating a temperature measurement method of a cell temperature measurement device according to an embodiment of the present disclosure.

As shown in FIG. 12 , in step S10 , the cell temperature measuring device 1 applies current to a pair of first end parts among a plurality of end parts of the Hall element 110 .

In this embodiment, the cell temperature measuring device 1 includes a micro-well plate 130 on which cells are placed and located above the Hall element 110, a Hall element 110 having an abnormal Hall effect characteristic, and It may include an electrode pad 120 electrically connected to the Hall element 110 so that a current may be applied to the Hall element 110 or a voltage of the Hall element 110 may be measured.

At this time, the Hall element 110 may have a cross-shaped structure including a plurality of end portions, specifically, a structure in which two linear Hall bars having the same width cross each other at an intersection point, and a plurality of end portions It is located at each end of the two Hall bars, and at least a portion of the plurality of end portions may have a shape in which the width increases as the distance from the intersection point increases.

In addition, the electrode pad 120 may be configured to be electrically connected to each distal end of the Hall element 110, and the first electrode pad 121, the second electrode pad 122, the third electrode pad 123 and A fourth electrode pad 124 may be included.

That is, the cell temperature measuring device 1 may be electrically connected to a pair of first end portions among end portions of the Hall element 110 through the electrode pad 120 to apply current to the Hall element 110 . Here, the first end part may be an end part corresponding to the first electrode pad 121 and the third electrode pad 123 among the electrode pads 120 described above.

In step S20, the cell temperature measuring device 1 applies an external magnetic field in a direction perpendicular to the direction of the current applied to the Hall element 110.

In this embodiment, in order to apply an external magnetic field, an electromagnet unit 310 including a coil to which current is applied and a cooling unit 330 for cooling the coil may be included. In this embodiment, since heat may be generated in the electromagnet unit 310 when a magnetic field is applied, by using the cooling unit 330 to cool the electromagnet unit 310, it is possible to prevent a failure due to heat generation.

In step S30, the cell temperature measuring device 1 measures the Hall voltage of the Hall element 110 at a pair of second end parts among the end parts of the Hall element 110.

In this embodiment, the cell temperature measuring device 1 is placed at the intersection of the linear Hall bars based on the abnormal Hall effect generated when an external magnetic field is applied in a direction perpendicular to the direction of the current applied to the Hall element 110. The temperature of the cell is measured, and a Hall voltage according to a change in perpendicular magnetic anisotropy may be generated at an intersection point where the linear Hall bars of the Hall element 110 intersect.

Accordingly, the cell temperature measuring device 1 may be connected to a pair of second end parts among the plurality of end parts through the electrode pad 120 to measure the Hall voltage of the Hall element. Here, the second end portion may indicate an end portion corresponding to the second electrode pad 122 and an end portion corresponding to the fourth electrode pad 124 .

In step S40, the cell temperature measuring device 1 directly or indirectly communicates with the Hall element 110 based on the temperature table including the relationship between Hall voltage and temperature, the current applied to the Hall element 110, and the external magnetic field. Calculates the temperature of the connected cells.

That is, the cell temperature measuring device 1 may calculate the temperature of the cell based on a change in Hall voltage before the cell is heat-conductively connected to the Hall element 110 and after the cell is heat-conductively connected to the Hall element 110 .

In this case, in this embodiment, the change in Hall voltage may be based on the change in magnetization value of the Hall element 110 connected to the cell by thermal conduction. In addition, the temperature table may be set based on the inverse proportionality between the magnetization value and Curie temperature of the Hall element 110 and the proportional characteristic between the Hall voltage and magnetization value of the Hall element 110, and may be stored in a memory (not shown). can

Embodiments according to the present invention described above may be implemented in the form of a computer program that can be executed on a computer through various components, and such a computer program may be recorded on a computer-readable medium. At this time, the medium is a magnetic medium such as a hard disk, a floppy disk and a magnetic tape, an optical recording medium such as a CD-ROM and a DVD, a magneto-optical medium such as a floptical disk, and a ROM hardware devices specially configured to store and execute program instructions, such as RAM, flash memory, and the like.

Meanwhile, the computer program may be specially designed and configured for the present invention, or may be known and usable to those skilled in the art of computer software. An example of a computer program may include not only machine language code generated by a compiler but also high-level language code that can be executed by a computer using an interpreter or the like.

In the specification of the present invention (particularly in the claims), the use of the term "above" and similar indicating terms may correspond to both singular and plural. In addition, when a range is described in the present invention, it includes an invention in which individual values belonging to the range are applied (unless there is a description to the contrary), and each individual value constituting the range is described in the detailed description of the invention Same as

The steps constituting the method according to the present invention may be performed in any suitable order unless an order is explicitly stated or stated to the contrary. The present invention is not necessarily limited according to the order of description of the steps. The use of all examples or exemplary terms (eg, etc.) in the present invention is simply to explain the present invention in detail, and the scope of the present invention is limited due to the examples or exemplary terms unless limited by the claims. it is not going to be In addition, those skilled in the art can appreciate that various modifications, combinations and changes can be made according to design conditions and factors within the scope of the appended claims or equivalents thereof.

Therefore, the spirit of the present invention should not be limited to the above-described embodiments and should not be determined, and all scopes equivalent to or equivalently changed from the claims as well as the claims described below are within the scope of the spirit of the present invention. will be said to belong to

1: Cell temperature measurement device
100: temperature measuring unit 110: Hall element
120: electrode pads 121 - 124: first fourth electrode pad
130: microwell plate 200: current applying unit
300: magnetic field application unit 310: electromagnet unit
320: power supply unit 330: cooling unit
400: signal analysis unit 500: control unit

Claims (20)

As a cell temperature measurement device,
a Hall element including a plurality of end portions and having an anomalous Hall Effect (AHE) characteristic;
a current supply unit electrically connected to a pair of first end portions among the end portions to apply a current to the Hall element;
a magnetic field application unit for applying an external magnetic field in a direction perpendicular to the direction of the current applied to the Hall element;
a signal analyzer connected to a pair of second end portions among the end portions to measure a Hall voltage of the Hall device; and
A control unit for calculating the temperature of a cell directly or indirectly connected to the Hall element by heat conduction based on a temperature table including a relationship between Hall voltage and temperature, the current applied to the Hall element, and the external magnetic field,
In the cell temperature measuring device, a microwell plate is provided above the hall element, the cells are placed on the microwell plate, and a hole provided at a position where the microwell plate and the center side of the hall element contact each other Based on this, the cell and the Hall element are implemented to be thermally conductively connected,
The controller calculates the temperature of the cell based on a change in the Hall voltage due to a change in temperature caused by heat conduction with the Hall element through the micro-well plate of the cell,
Cell temperature measurement device.
According to claim 1,
The Hall element,
It is a structure in which two linear Hall bars having the same width cross each other at the intersection,
The plurality of end portions are located at each end of the two hall bars, and at least a portion of the plurality of end portions has a kite-shaped shape gradually widening as the distance from the intersection point increases,
The Hall element,
It includes a ferromagnetic magnetic alloy having perpendicular magnetic anisotropy in which any one of Co, Fe, Ni, CoFe and CoNi and any one of Cu, Ti, Al and Ru are combined into an alloy, and 300 K according to the composition ratio of the magnetic alloy. having a Curie temperature in the temperature range of from 450 K to
Cell temperature measurement device.
According to claim 2,
a substrate on which the Hall element is lithographically patterned; and
Further comprising a plurality of electrode pads electrically connected to the plurality of end portions, respectively,
Cell temperature measurement device.
According to claim 3,
The substrate is rectangular, and the plurality of end portions and the plurality of electrode pads are located at corners of the substrate,
Cell temperature measurement device.
According to claim 1,
The control unit,
Calculating the temperature of the cell based on a change in Hall voltage due to a temperature change of the Hall element before the cell is thermally conductively connected to the Hall element and after the cell is thermally conductively connected to the Hall element,
Cell temperature measurement device.
According to claim 5,
The change in the Hall voltage is
Based on the change in the temperature of the Hall element and the change in the magnetization value of the Hall element due to the heat conduction with the cell,
Cell temperature measurement device.
According to claim 1,
The temperature table is
Set based on the inverse proportional characteristic of the magnetization value and Curie temperature of the Hall element and the proportional characteristic of the Hall voltage and magnetization value of the Hall element,
Cell temperature measurement device.
According to claim 1,
The Hall element,
Including a plurality of layers,
The plurality of layers,
a first layer that is non-magnetic;
a second layer formed on the first layer and having ferromagnetism in which an extraordinary Hall effect is generated by a magnetic field applied from the magnetic field applying unit; and
A third layer formed on the second layer and having a non-magnetic,
Cell temperature measurement device.
According to claim 8,
The second layer,
Having an easy axis of magnetization in a direction perpendicular to the interface by perpendicular magnetic anisotropy induced at the interface in contact with the first layer or the third layer,
Cell temperature measurement device.
According to claim 8,
The thickness of the second layer,
0.4 nm to 1.0 nm,
Cell temperature measurement device.
According to claim 8,
The material of the first layer and the third layer are the same,
Cell temperature measurement device.
According to claim 8,
The second layer,
Any one of Co, Fe, Ni, CoFe and CoNi and any one of Cu, Ti, Al and Ru are combined into an alloy,
Cell temperature measurement device.
According to claim 8,
The Hall element,
Further comprising a protective layer that protects at least some or all of the Hall elements,
Cell temperature measurement device.
According to claim 13,
The protective layer,

and

including at least one of
Cell temperature measurement device.
delete According to claim 2,
The Hall element,
Having a Curie temperature greater than or equal to the maximum value in the temperature range of the cell,
Cell temperature measurement device.
delete According to claim 1,
The signal analysis unit includes a lock-in amplifier connected to the second end and measuring a Hall voltage of the Hall element,
The magnetic field applying unit includes a coil to which current is applied,
Supplying an alternating current to the coil in synchronization with the reference signal supplied from the lock-in amplifier,
Cell temperature measurement device.
According to claim 1,
The magnetic field applying unit,
an electromagnet unit including a coil to which current is applied; and
Including a cooling unit for cooling the coil,
Cell temperature measurement device.
A temperature measurement method of a cell temperature measuring device including a Hall element including a plurality of end portions and having an anomalous Hall Effect (AHE) characteristic, comprising:
applying a current to the Hall element to a pair of first end portions among the end portions;
applying an external magnetic field in a direction perpendicular to the direction of the current applied to the Hall element;
measuring a Hall voltage of the Hall element at a pair of second end portions among the end portions; and
Calculating the temperature of a cell directly or indirectly thermally connected to the Hall element based on a temperature table including a relationship between Hall voltage and temperature, the current applied to the Hall element, and the external magnetic field;
In the cell temperature measuring device, a microwell plate is provided above the hall element, the cells are placed on the microwell plate, and a hole provided at a position where the microwell plate and the center side of the hall element contact each other Based on this, the cell and the Hall element are implemented to be thermally conductively connected,
Calculating the temperature of the cell,
Calculating the temperature of the cell based on the Hall voltage dependent on the temperature change of the Hall element and the Hall element changed by heat conduction through the micro-well plate of the cell,
How to measure cell temperature.

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