JP2010217120A - Temperature sensor by mems technology and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for achieving a sensor suitable for monitoring the health and an environment, by being installed on a large number of organism individuals. <P>SOLUTION: A bimorph element is a MEMS device manufactured by a MEMS technology, and is characterized by having two bimorph plates arranged so as to face each other and so that the displacement direction becomes the approaching direction to a mate. Depending on an embodiment, these two bimorph plates may be arranged so that both its plate surfaces become vertical to a bottom and/or a top surface of a substrate for supporting the bimorph plates. Depending on an embodiment, an upper side of the bimorph plates may be arranged so as not to exceed a height of the substrate and so that its lower side does not become lower than a height of the bottom of the substrate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a bimorph element having a novel structure manufactured using MEMS (Microelectromechanical systems) technology and a method for manufacturing the same. This bimorph element is suitable for application to an ultra-low power consumption temperature sensor.

Background of the Invention

  In recent years, interest in monitoring the health of the living body and the state of the environment has increased. For example, recently, the occurrence of a new type of avian influenza has become a problem (see Non-Patent Document 1), but this avian influenza has been reported to cause infections not only in domestic animals but also in humans, resulting in fatalities such as deaths. Has been reported. With regard to avian influenza, it has been pointed out that it may be mutated to a strain with human as the main host in the future, and when such a new species occurs, explosive infections occur, many human lives are lost, Serious damage is expected to occur, including a significant impact on activities. Therefore, especially in countries and regions where poultry farming is prominent, if the occurrence of bird flu can be monitored and the occurrence of bird flu can be detected at an early stage of infection, It helps prevent the spread of infection, and even if a new type of flu occurs, it is thought that time for vaccine development can be earned. For example, for such a situation, technology for monitoring health and environmental conditions is one of the fields in which great development is desired.

  A temperature sensor is a promising sensor as a sensor for sensing the health state of a living body. For example, chickens suffering from avian influenza show an increase in body temperature, similar to a person who has a cold. The body temperature of a healthy chicken is 41.5 to 42 ° C, but the body temperature of a chicken affected with avian influenza is usually 43 ° C or higher. Therefore, if this body temperature can be monitored, healthy chickens can be easily distinguished from other chickens. However, for example, a chicken farm usually contains tens of thousands of chickens. Therefore, it is naturally impossible to attach temperature sensors to all chickens, and even if temperature sensors are attached to 1% chickens, the number is up to several hundred. In order to monitor such a large number of individuals, the sensor is required to have special performance.

  One of them is power saving. Due to the large number of individuals, it is not possible to change sensors frequently. In addition, since sensors are attached to a living body and the number of sensors is large, it is preferable to collect data wirelessly. For this reason, since it is necessary to incorporate a transmitter in a sensor, the electric power for operating it is required. Therefore, the power consumed by the heat sensing element needs to be as small as possible.

  The next requirement is a low cost sensor. Due to the large number of individuals, if each sensor is expensive, it becomes impossible to attach sensors to a large number of individuals because of cost. Therefore, it must be possible to provide individual sensors at a low price.

  Furthermore, since it is attached to a living body, it must be small and light. This is especially true when attached to a chicken or the like because the living body itself is small. In addition, it must be possible to measure temperature with high accuracy and high resolution. For example, in the case of a human being, even if the body temperature is different from normal only by 0.5 ° C., it can be recognized that a cold is caught. Therefore, a large temperature measurement error cannot be tolerated in order to make an accurate judgment, and the temperature resolution must be high.

  In order to facilitate manufacturing, reduce costs, and reduce size and weight, it is preferable to incorporate the sensor into an IC circuit. It would be desirable to use MEMS technology. Currently, there are several types of MEMS-based temperature sensors, but these include [1] temperature measurement using resistance (Non-Patent Document 2) and [2] thermocouples. And (3) non-patent documents 3) and [3] surface acoustic waves (SAW) to measure temperature (non-patent documents 4 and 5). Of these, [1] and [2] are under development and are widely used, but they have the disadvantage of high power consumption and are not suitable for the above-mentioned purpose of health / environment monitoring. In [3], the temperature is measured by irradiating an RF signal like a radar and measuring the response time using the fact that the velocity of the surface acoustic wave changes depending on the temperature (Non-Patent Document 4). ). For this reason, the sensor itself does not require power and is excellent in terms of power consumption. However, the number of passive SAW sensors that can be read simultaneously by the RF signal irradiation / reader is about 10 at most, and the readable distance is about 10 m at most (Non-patent Document 5). . As mentioned above, tens of thousands of chickens are usually raised in poultry farms, and detection of avian influenza outbreaks is necessary because at least 1% of individuals want to attach a detector. The number of detectors is on the order of several hundred. Then, when measuring the temperature of many individuals, it is difficult to use the SAW sensor. Therefore, this sensor is also not suitable for the above-mentioned purpose of health / environment monitoring.

  Another known temperature sensor uses a bimorph. A bimorph is a structure in which two types of materials having different thermal expansion coefficients are laminated in two layers. This is a strip-shaped flat plate, one end of which is fixed and the other end is a free end. ) Is often used. Since the two types of materials constituting the bimorph have different coefficients of thermal expansion, the beam part warps when the temperature rises. By detecting this deformation, temperature detection can be performed. Since the deformation of the bimorph itself occurs without the need for electric power, it is excellent in power saving, and in this respect, has a surface suitable for the health / environment monitoring described above.

Patent Document 1 discloses a temperature sensor using two types of bimorphs, one of which is used as a temperature sensor and the other is used as a reset switch. The reset switch bimorph is provided with a claw portion for engaging the temperature sensor bimorph. When the temperature rises, the temperature sensor bimorph bends and engages the claw portion of the reset switch bimorph. Then, even if the temperature decreases and the temperature sensor bimorph attempts to return to its original shape, it cannot be recovered because it is engaged with the claw portion. For this reason, this sensor functions as a memory type sensor that memorizes that the temperature has risen above a predetermined value in the past. The reset switch bimorph is made of a piezoelectric material and bends when a voltage is applied to remove the claw portion from the temperature sensor bimorph. Then, the temperature sensor bimorph can return to its original shape, and can operate as a temperature sensor again. Patent Document 2 also describes that a bimorph is used as a temperature sensor in the invention of a non-contact type IC tag that stores a past temperature rise.
These sensors are intended to be used for applications such as confirming that the temperature of the luggage being stored is kept within an allowable range. Used to show that the temperature of the bimorph has increased during transportation by showing the warped state of the bimorph. That is, these sensors act as a kind of fuse. These temperature sensors are configured for the purpose of memorizing that the temperature has risen above a predetermined value in the past, so for the purpose of health monitoring described above, which requires continuous body temperature measurement. Not very suitable. For example, since the structure of Patent Document 1 has a structure in which the bimorph is kept in a warped state, it is impossible to perform continuous body temperature measurement. In addition, the bimorph structures of Patent Documents 1 and 2 cannot reduce the temperature measurement error, and that point is insufficient to be used for the purpose of the health monitoring described above.

  Patent Documents 3 and 4 describe a temperature sensor configured to detect a plurality of temperatures by using a plurality of bimorph plates having different lengths. However, these sensors are not microsensors using MEMS technology, but are manufactured by traditional machining. Therefore, the size of the sensor is relatively large and the manufacturing cost is high. Furthermore, even if the bimorph sensor depicted in the drawings of these documents is manufactured by the MEMS manufacturing process, the shape is not suitable for it. Therefore, these sensors are also not suitable for use for the purpose of health monitoring described above. Further, the bimorph structures of Patent Documents 3 and 4 cannot reduce the temperature measurement error as well as those of Patent Documents 1 and 2, and are still insufficient for use for the above-mentioned health monitoring purposes.

  In addition, the existing bimorph temperature sensor has a drawback that the measurable temperature range cannot be widened. Although the body temperature of the living body can be varied within a relatively large range of 5 to 6 ° C, it has a high steadiness depending on the physical condition (disease). It exhibits a subtle temperature change. Therefore, a sensor for measuring the temperature of a living body must be capable of measuring with high accuracy and capable of measuring a wide temperature range. Since one bimorph has sensitivity only at one temperature, in order to measure a wide temperature range, a large number of bimorphs having different sensing temperatures must be incorporated in one sensor. The bimorph structure described in (1) is not suitable for such applications, and the production cost and size are significantly increased. As far as the applicant knows, there is no conventional bimorph structure that is compact, lightweight, can be manufactured at low cost, has a wide measurable temperature range, and has high temperature resolution.

  As a result of grasping the prior art as described above and considering them as described above, the inventors have found that there is a sensor suitable for monitoring the health and environment of the living body that satisfies the above-mentioned demands in the prior art. I came to the conclusion that there was a need for new development. In view of such a background, an object of the present invention is to provide a technique for realizing a temperature sensor that can suitably cope with monitoring of the health of a large number of living bodies and monitoring of the environment.

  A bimorph element according to the present invention is a MEMS device manufactured by MEMS technology, and has two bimorph plates arranged so as to face each other and to have a displacement direction approaching the other party. Features.

  By using two bimorph plates and arranging them so as to bend in a direction approaching each other, the error in the sensing temperature can be remarkably reduced as compared with the prior art. Moreover, since it manufactures with the precision processing technology of MEMS, the space | interval and length of a bimorph board can be controlled precisely, and it is possible to make many bimorph elements from which sensing temperature differs in one sensor element. Since the error in the sensing temperature of each element is small, a unit temperature interval of, for example, 1 ° C. can be divided into a large number of sensing temperatures, and temperature measurement with high resolution can be performed. In addition, since the bimorph element itself does not require electric power for operation, it is advantageous in reducing the power consumption of the entire sensor. Further, by using the MEMS technology, the device can be manufactured in a small size and at low cost.

  Depending on the embodiment, each of the two bimorph plates may have a protruding end portion protruding in the displacement direction at the tip end portion thereof.

  Depending on the embodiment, both of the two bimorph plates may be arranged so that their plate surfaces are perpendicular to the bottom surface and / or the top surface of the base that supports the bimorph plate.

  In some embodiments, the bimorph plate extends laterally from the base body, the upper part thereof does not exceed the height of the upper part of the base body, and the lower side part thereof is lower than the height of the bottom part of the base body. It may be arranged so as not to be.

  Depending on the embodiment, both of the two bimorph plates may be formed of an insulator on the surface facing the other bimorph plate and formed of a conductive material on the surface not facing the other bimorph plate. Good. However, even on the surface facing the other bimorph plate, it may be configured such that conduction with the conductive material can be obtained at locations where the bimorph plates can be displaced and come into contact with each other.

  Embodiments of the present invention include a MEMS bimorph element composite having a plurality of MEMS bimorph elements having one or more of the features described above. In this MEMS bimorph element composite, the interval between the two bimorph plates of each MEMS bimorph element may be configured to be different from the interval between the two bimorph plates of the other MEMS bimorph elements.

  Embodiments of the invention include a temperature sensor comprising at least one of a MEMS bimorph element comprising one or more of the features described above, or a MEMS bimorph element composite as described above. The temperature sensor is configured to detect heat by detecting contact of the two bimorph plates of a MEMS bimorph element or a MEMS bimorph element composite.

  According to an embodiment of the present invention, an MEMS bimorph element is characterized in that two bimorph plates are formed by a MEMS manufacturing process so as to face each other and to have a displacement direction approaching the other party. Includes manufacturing methods.

  Various features and advantages included within the scope of the present invention will be described in more detail below with reference to the accompanying drawings.

It is a figure for demonstrating the concept of the MEMS bimorph element 100 by this invention. FIG. 2 is a diagram depicting an example in which 30 sets of the MEMS bimorph elements of FIG. 1 are formed on one frame-type substrate. It is a figure which shows the simulation result of the temperature detection capability of the MEMS bimorph element composite_body | complex by this invention. It is the figure which drew some examples which can be taken as the front-end | tip shape of the bimorph beam of the MEMS bimorph element by this invention. It is a figure for demonstrating an example of the manufacturing process of the MEMS bimorph element by this invention. It is a figure for demonstrating the outline | summary of the circuit structure in the case of utilizing the MEMS bimorph element by this invention for a temperature sensor.

Detailed Description of the Preferred Embodiment

  FIG. 1 is a view for explaining the concept of a MEMS bimorph element 100 according to the present invention. The MEMS bimorph element 100 includes two bimorph plates 120 and 130 extending laterally from the side surface 110 b of the base 110. As shown in the figure, the bimorph plates 120 and 130 are supported at one end by the side surface 110b of the base 110, and the other ends are free ends that are not fixed. That is, it has a so-called cantilever structure. The bimorph plates 120 and 130 are arranged so as to face each other, and their displacement directions (deflection directions) are arranged so as to approach each other.

  The bimorph plates 120 and 130 have a two-layer structure. In this embodiment, the layers 120a and 130a on the surface facing the other bimorph plate are base materials, and may be a base material used in MEMS, such as silicon, glass, ceramic, polymer, and the like. In some embodiments, metal may be used. The material of the layers 120a, 130a can be the same material as the material of the base 110, and thus the base layers 120a, 130a of the bimorph plates 120 and 130 are integrally formed with the base 110 using a MEMS manufacturing process. be able to,

  In the bimorph plates 120 and 130 in the present embodiment, the layers 120b and 130b on the surface not facing the other bimorph plate are formed of a conductive material, and can be formed of, for example, metal, oxide, nitride, or the like. . The conductive layers 120b and 130b can be formed by using, for example, a thin film formation technique, and can be performed by, for example, sputtering, electroplating, electroless plating, PVD, CVD, chemical deposition, or the like. In the illustrated embodiment, the portions 110d and 110e of the base 110 are also coated with the same material as that of the conductive layers 120b and 130b, and these are used for electrical connection between the conductive layers 120b and 130b and the outside. be able to.

  The lengths of the bimorph plates 120 and 130 may be any length as long as they can be manufactured by the MEMS manufacturing process, and may be, for example, a length of several tens of nm to several mm. The thickness of the base layers 120a and 130a and the thickness of the upper layers 120b and 130b should be determined by the temperature to be detected and the coefficient of thermal expansion (CTE) of the layer material. Both can be several tens of nm to 100 μm thick.

  The material of the facing layers 120a and 130a and the material of the back layers 120b and 130b are selected so that the thermal expansion coefficient of the back layers 120b and 130b is larger than the thermal expansion coefficient of the facing layers 120a and 130a. Is done. For this reason, when the temperature rises, each of the bimorph plates 120 and 130 bends so as to approach the other party, and finally comes into contact with each other at the tip portion. If the layers 120b and 130b of the conductive material are in electrical contact at the contact point, it can be sensed that the temperature is equal to or higher than a predetermined value by detecting the occurrence of conduction. .

  As described above, the conductive layers 120b and 130b are in electrical contact with each other in such a portion that the conductive layers 120b and 130b conduct when the bimorph plates 120 and 130 are in contact with each other in a curved manner. Some sort of processing needs to be done. In the present embodiment, protruding end portions 120c and 130c raised in the bending direction are provided at the tip portions of the bimorph plates 120 and 130, and the conductive layers 120b and 130b extend to the surfaces of the protruding end portions 120c and 130c. Is formed. Therefore, when the bimorph plates 120 and 130 are curved and the projecting ends 120c and 130c come into contact with each other, the conductive layers 120b and 130b come into electrical contact, and conduction is obtained.

  As shown in the drawing, the MEMS bimorph element of the present invention is characterized in that two bimorph cantilevers are arranged so as to face each other and the displacement directions thereof are directions close to each other. To do. And it is comprised so that it can detect that heat rose more than predetermined value by these contacts. By configuring so that heat is sensed by bending of two levers, heat can be sensed with higher accuracy than in the case of a conventional lever. In the case of one conventional lever, the sensitivity of the temperature at which the lever bends and contacts the contact point is approximately 0.5 ° C. However, in the embodiment of the present invention, this can be increased to about 0.1 ° C. did it.

  As is well known, the difference of 0.5 ° C. in the body temperature of a living body is not small, for example, in humans, a body temperature of 36.5 ° C. is considered normal, but a body temperature of 37 ° C. is clearly classified as having a disease. . Therefore, the accuracy of a conventional bimorph temperature sensor with a sensitivity of 0.5 ° C. cannot sufficiently distinguish between a healthy state and a diseased state, and is quite insufficient for measuring a living body temperature. However, according to the embodiment of the present invention, since the sensitivity could be increased to 0.1 ° C., it can be sufficiently used for measuring the temperature of a living body.

  Moreover, since temperature detection by a thermal bimorph detects that the bimorph is bent by heat and contacts the contact point, one bimorph element can detect only a specific temperature. When detecting a plurality of temperatures, as described in Patent Documents 3 and 4, it is necessary to incorporate a plurality of bimorph elements having different sensing temperatures into the sensor element. However, in the prior art represented by Patent Documents 3 and 4, since the heat sensing error of the bimorph itself is large and the machining error is also relatively large, the difference in the detected temperature of each bimorph cannot be made so small. It was. That is, for example, only a rough resolution such as a 0.5 ° C. step can be measured, and a bimorph temperature sensor excellent in temperature resolution could not be made.

  On the other hand, the MEMS bimorph element according to the present invention is a MEMS device in addition to a decrease in temperature detection error due to the use of two bimorph cantilevers, and therefore the length and thickness of the cantilever and the gap between the two cantilevers. Can be controlled precisely. For example, the sensing temperature of the MEMS bimorph element 100 according to the present invention can be determined by determining the thickness, length, and material of the base layers 120a and 130a and the upper layers 120b and 130b of the bimorph cantilevers 120 and 130, and the gap between the bimorph cantilevers 120 and 130. The size of the gap can be precisely controlled in the MEMS manufacturing process. Therefore, a temperature sensor having high temperature resolution can be formed by forming a large number of bimorph elements having different gap sizes in one sensor.

  FIG. 2 depicts an example (MEMS bimorph element composite 200) in which 30 sets of the MEMS bimorph elements of FIG. 1 are formed on one frame-type substrate. In this figure, each of the structures indicated by reference numeral 202 corresponds to the MEMS bimorph element 100 of FIG. In the figure, reference numeral 202 is attached only at three places, but it can be easily determined from FIG. 2 that 30 equivalent structures are drawn in total. Each of these bimorph structures 202 is different from the other bimorph structures 202 in the gap between two bimorph arms. That is, the temperature at which the two bimorph arms contact each other is different for each bimorph element 202, in other words, the sensing temperatures are all different. In the case of the MEMS bimorph element composite 200 of the example, the difference in contact temperature is set to 0.2 ° C. Since 30 bimorph heat sensing structures are formed in total, temperature measurement can be performed over a range of 6 ° C. with a resolution of 0.2 ° C.

  FIG. 3 shows a simulation result of the temperature detection capability of the MEMS bimorph element composite as shown in FIG. However, unlike the figure, there are 20 bimorph element elements in total. Since the resolution is 0.2 ° C., the temperature detection range is 4 ° C. The base layer material of the bimorph arm was silicon, the upper layer material was nickel, the base layer thickness was 3 μm, and the upper layer thickness was 0.3 μm. The horizontal axis in FIG. 3 is the temperature, and the vertical axis is the gap between the bimorph arms. As shown in FIG. 3, there is a clean linear relationship between the sensed temperature (the temperature at which the two bimorph arms are in contact) and the gap between the bimorph arms over a range of 39.5 ° C. to 43.5 ° C. is there.

  As illustrated in FIG. 1, in the MEMS bimorph element 100 according to the present embodiment, the bimorph arms 120 and 130 extend laterally with respect to the top surface 110 a and the bottom surface 110 c of the base 110, but the upper side thereof has a height of 110 a. The lower side thereof is configured not to be lower than the height of the bottom surface 110c. Further, the plate surfaces of the bimorph arms 120 and 130 are arranged so as to be perpendicular to the upper surface 110a and the bottom surface 110c of the base 110, and the displacement directions of the bimorph arms 120 and 130 are close to each other, that is, the base portion. 110 is parallel to the top surface 110a and the bottom surface 110c of the 110, so that not only the non-displaced state depicted in FIG. 1 but also the bimorph arms 120, 130 are in a deformed displacement state, the upper side of the bimorph arms 120, 130 and The lower side does not exceed the height range defined by the upper surface 110a and the bottom surface 110c of the base 110.

  Since the bimorph arms 120 and 130 do not exceed the height range defined by the top surface 110a and the bottom surface 110c of the base 110, even if there are any elements above or below the bimorph arms 120 and 130 in FIG. There is no problem in the operation of the bimorph arms 120 and 130. This means that the MEMS bimorph element 100 does not necessarily have to be mounted on the circuit board, and can be formed integrally with the circuit board. It is also possible to place another circuit element on the top surface 110a or the bottom surface 110c in FIG. These characteristics are very advantageous for downsizing and cost reduction of the sensor. It can be clearly understood from FIG. 2 that these advantages are not lost even in the MEMS bimorph element composite 200 including a large number of MEMS bimorph elements 100. The above-described characteristics of the MEMS bimorph element 100 and the MEMS bimorph element complex 200 are very advantageous characteristics when packaged in an IC.

  As described above, in the MEMS bimorph element 100 of FIG. 1, the projecting end portions 120c and 130c raised in the bending direction of the respective arms are provided at the distal end portions of the bimorph arms 120 and 130. This tip shape has two functions. One is to make sure that the bimorph arms 120 and 130 are in contact with each other, and the other is to reduce the contact area. Reducing the contact area helps to prevent the contacted bimorph arms 120 and 130 from sticking and becoming unable to be separated.

  When the structure is on the order of μm and nm, the influence of intermolecular force cannot be ignored, and in MEMS devices, there is often a problem that structures are stuck together by intermolecular force. This problem is known as Thermal Hysteresis and has been studied in MEMS-based infrared imaging systems (Non-Patent Documents 6 and 7).

  Also in the MEMS bimorph element 100, if the bimorph arms 120 and 130 are stuck and cannot be separated from each other, the temperature cannot be detected any more. Therefore, we want to avoid this situation as much as possible. However, according to the tip shape of the bimorph arm as in this embodiment, the shape of the raised portions 120c and 130c is the tip shape, and the contact area can be reduced. Can be minimized, and sticking can be prevented.

  In the example of FIG. 1, the shape of the raised portions 120 c and 130 c has a semicircular cross section, but the shape of the raised portions is not limited to this. For example, as shown in FIG. 4, the cross section may be various, such as a circular shape, a hexagonal shape, a rectangular shape, a trapezoidal shape, a key shape, and the like. When a large number of bimorph elements are formed as shown in FIG. 2, the shape of the raised portion in one element may be different from the shape of the raised portion in another element. These shapes can be easily formed by existing MEMS manufacturing methods.

  The MEMS bimorph element and the composite according to the present invention can be manufactured in a small size and at a low cost, can perform a high-range and high-resolution temperature measurement, and further requires no power for the operation of the bimorph itself. For applications such as chickens in chicken farms where long-term real-time temperature measurement is performed by attaching to a large number of individuals, it has very favorable characteristics. Therefore, it can be said that it is most suitable for the aforementioned health / environment monitoring. Of course, the use of the MEMS bimorph element according to the present invention is not limited thereto, and may be used for any application. High-range and high-resolution temperature measurement, low-cost manufacturing, easy packaging into IC, and no power consumption can be a great advantage in various temperature measurements Is easy to imagine.

  FIG. 5 is a diagram for explaining an example of the manufacturing process of the MEMS bimorph element according to the present invention. First, a substrate such as silicon is prepared (1), and a base layer structure pattern is formed thereon (2). Then, in order to make a conductive layer and a circuit, a film is formed with nickel or the like (3), and a film other than a necessary part is removed using an etching technique (4) (5). Finally, if the substrate under the bimorph arm is removed by etching (6), a bimorph element in which the bimorph and the circuit are formed can be obtained.

  In FIG. 5, two bimorph element structures are depicted, both of which appear to have the same bimorph arm length and gap between the two bimorph arms. It goes without saying that there is no problem.

  Since the above manufacturing process is the same as a conventional CMOS manufacturing process, the MEMS bimorph element according to the present invention can be formed alone, or can be formed together with other CMOS circuits.

  FIG. 6 is a diagram for explaining an outline of a circuit configuration when the MEMS bimorph element according to the present invention is used for a temperature sensor. The temperature sensor 600 according to this embodiment includes a CPU 602, a memory 604, a transmitter 606, an antenna 608, a bimorph element 610, and the like. Although not shown, a battery for supplying power to the temperature sensor 600 is also provided. The bimorph element 610 is a MEMS bimorph element according to the present invention, and can be, for example, the MEMS bimorph element 100 or the MEMS bimorph element composite 200 described above. The CPU 602 periodically monitors the bimorph element 610 to check whether the two bimorph arms of the element 610 are in contact. As a method for checking, a method for detecting whether or not a current flows or a method for detecting a change in the applied voltage can be used. The CPU 602 stores the monitoring result of the bimorph element 610 in the memory 604. The memory 604 may store software for causing the CPU 602 to execute necessary control. (Such software may be stored in a memory different from the memory 604.) The CPU 602 periodically transmits data stored in the memory 604 to the outside using the transmitter 606. Data is transmitted to the outside via the antenna 608. As a communication method, any existing method such as infrared communication or Bluetooth may be used. However, it is preferable to adopt a method with low power consumption and a long communicable distance.

The preferred embodiments of the present invention have been described in detail above, but these descriptions and drawings are not intended to limit the scope of the present invention, but are presented only for the purpose of understanding the present invention. It should be understood that it is only a thing. Some of the preferred embodiments of the present invention are specified in the appended claims, but the embodiments of the present invention are described in the claims, in the description and in the drawings explicitly. Without being limited, various forms can be taken without departing from the spirit of the present invention. The present invention includes in its scope all novel and useful configurations that can be taught from these documents, whether or not explicitly disclosed in the claims, specification and drawings.
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Claims (8)

  A MEMS bimorph element comprising two bimorph plates arranged so as to face each other and in a direction in which a displacement direction approaches a partner.   2. The MEMS bimorph element according to claim 1, wherein each of the two bimorph plates has a protruding end portion protruding in a displacement direction at a tip end portion thereof. 3.   The two bimorph plates are both arranged such that the plate surface thereof is perpendicular to the bottom surface and / or the top surface of the base that supports the bimorph plate. MEMS bimorph element.   The bimorph plate extends laterally from the base body, and the upper side portion thereof is disposed so as not to exceed the height of the base body, and the lower side portion thereof is not lower than the height of the bottom surface of the base body. The MEMS bimorph element according to claim 3.   In each of the two bimorph plates, a surface facing the other bimorph plate is formed of an insulator, and a surface not facing the other bimorph plate is formed of a conductive material, provided that the other bimorph plate is not provided. 5. The MEMS according to claim 1, wherein the bimorph plate is also configured to be electrically connected to the conductive material at a location where the bimorph plates can be displaced and contact each other on a surface facing the plate. Bimorph element.   A MEMS bimorph element composite having a plurality of MEMS bimorph elements according to any one of claims 1 to 5, wherein an interval between the two bimorph plates of each MEMS bimorph element is the two sheets of the other MEMS bimorph elements. A MEMS bimorph element composite configured to be different from the distance between the bimorph plates.   A temperature sensor comprising at least one of the MEMS bimorph element according to any one of claims 1 to 5 or the MEMS bimorph element complex according to claim 6, wherein the 2 of the MEMS bimorph element or the MEMS bimorph element complex. A temperature sensor configured to detect heat by detecting contact of a sheet of bimorph plates.   A method of manufacturing a MEMS bimorph element, wherein two bimorph plates are formed by a MEMS manufacturing process so as to face each other and so that a displacement direction is a direction approaching a partner.