JP2015210080A - Surface acoustic wave sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface acoustic wave sensor that can separate a plurality of analyte liquids having a droplet performed, and can attain a plurality of different inspections.SOLUTION: A surface acoustic wave sensor comprises: a piezoelectric element substrate that propagates a surface acoustic wave; and a convexity member in which a channel has an electrode performing a conversion of an electric signal and the surface acoustic wave, and a plurality of detection areas, which is arranged in a propagation path of the surface acoustic wave and into which a liquid serving as an analyte is introduced, is plurally provided in a direction perpendicular to a propagation direction, and which is longer than a side facing an adjacent detection area.

Description

  The present invention relates to a surface acoustic wave sensor.

The surface acoustic wave sensor is a sensor for inspecting (or component analysis) a liquid as a specimen or a specimen (substance to be examined) contained in the liquid.
In general, a surface acoustic wave sensor is formed between a pair of comb electrodes (IDT (Inter Digital Transducer)) formed on a piezoelectric substrate and the pair of comb electrodes, and a liquid as a specimen is dropped. Detection area.

  Patent Document 1 proposes a surface acoustic wave sensor including a plurality of surface acoustic wave sensors on one piezoelectric substrate. Since the surface acoustic wave sensor described in Patent Document 1 includes a plurality of detection regions, it can simultaneously detect a plurality of substances and measure physical properties on one piezoelectric substrate. Alternatively, since a plurality of detection regions are provided, it is possible to simultaneously perform a plurality of different tests on one specimen by providing the detection regions with individual recognition functions.

JP 2013-96866 A

However, in the surface acoustic wave sensor described in Patent Document 1, when different specimen liquids are dropped on each detection area, the amount and the dropping position of the specimen liquid dropped on the detection area are likely to be uneven. Therefore, when the amount of the sample liquid is large or when the dropping position is greatly deviated from the center, the sample liquid may flow to different detection regions, and a plurality of sample liquids may not be separated.
In addition, when a biofilm is individually formed with a solution in each detection region, it may flow to a different detection region, and a biofilm may not be formed individually in each detection region.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a surface acoustic wave sensor capable of separating a plurality of droplets of a specimen liquid and realizing a plurality of different tests. It is.

  In one embodiment of the present invention, a piezoelectric element substrate that propagates a surface acoustic wave, an electrode that converts an electric signal and the surface acoustic wave, and a liquid that is a specimen are disposed in a propagation path of the surface acoustic wave. A surface acoustic wave sensor comprising: a plurality of channels each having a plurality of detection regions provided in a direction perpendicular to the propagation direction; and a convex member longer than a side facing the adjacent detection region.

  One aspect of the present invention is the surface acoustic wave sensor described above, further including the convex member outside the detection region.

  One aspect of the present invention is the surface acoustic wave sensor described above, wherein the convex member is provided with a groove having a predetermined depth in a central portion.

  One aspect of the present invention is the above-described surface acoustic wave sensor, wherein the width of the groove of the convex member is one tenth or more of the distance of the detection region in the direction perpendicular to the propagation direction of the surface acoustic wave. long.

  One aspect of the present invention is the surface acoustic wave sensor described above, wherein the convex member includes a plurality of step portions having different heights.

  One aspect of the present invention is the above-described surface acoustic wave sensor, further including a sealing structure that prevents the electrode from coming into contact with a liquid, wherein the plurality of convex members are not crossed with each other. Extend to.

  One aspect of the present invention is the surface acoustic wave sensor described above, wherein the plurality of convex members have a hydrophobic surface.

  As described above, according to the present invention, it is possible to provide a surface acoustic wave sensor capable of separating a plurality of droplets of a specimen liquid and realizing a plurality of different tests.

1 is a schematic diagram illustrating a schematic configuration of a surface acoustic wave sensor (hereinafter, a SAW sensor) according to a first embodiment of the present invention. 3 is a schematic cross-sectional view for explaining a pattern of a structure of a convex portion 20. FIG. It is a figure which shows an example when a test substance liquid is dripped at the reaction area | region thin film. It is the schematic diagram which showed schematic structure of the SAW sensor of 2nd Embodiment of this invention. It is the schematic diagram which showed schematic structure of the SAW sensor of 3rd Embodiment of this invention. It is the schematic diagram which showed schematic structure of the SAW sensor of 4th Embodiment of this invention. It is the schematic diagram which showed schematic structure of the SAW sensor of 5th Embodiment of this invention. It is a block diagram for demonstrating an example of the drive circuit of SAW sensor 1 of 1st Embodiment of this invention. It is a block diagram for demonstrating an example of the drive circuit of SAW sensor 1-1 of 3rd Embodiment of this invention.

(First embodiment)
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram of a SAW sensor 1 according to this embodiment. FIG. 1A is a schematic top view of the SAW sensor 1, and FIG. 1B is a schematic cross-sectional view of the SAW sensor 1 as viewed from the cut surface A. FIG. 1C is a schematic cross-sectional view of the SAW sensor 1 as viewed from the cut surface B.

  The SAW sensor 1 (surface acoustic wave sensor) includes a piezoelectric element substrate 10, a plurality of comb-shaped electrodes 11 (comb-shaped electrodes 11-1 to 11-4), a plurality of reaction region thin films 13 (13-1, 13-2), a plurality of The sealing structure 14 (14-1, 14-2) and the convex member 20 (20-1 to 20-6) are included.

The piezoelectric element substrate 10 is a substrate that propagates SAW (surface acoustic wave). The piezoelectric element substrate 10 is preferably a surface acoustic wave through which a transverse wave propagates, such as a 36 ° Y plate 90 ° X propagation quartz substrate or a 36 ° Y plate X propagation LiTaO ₃ .

The comb-shaped electrode 11 is an electrode configured on the piezoelectric element substrate 10. The comb electrode 11 is a pair of electrodes facing each other. The IDT 11 is made of, for example, an aluminum thin film.
The comb-shaped electrode 11-1 and the comb-shaped electrode 11-2 are metal electrodes formed by a comb-like pattern constituting the transmission-side electrode unit. The comb electrode 11-1 includes a transmission electrode 11-1a and a transmission electrode 11-1b. The transmission electrode 11-1a and the transmission electrode 11-1b are electrodes that perform conversion between an electric signal and SAW. The comb electrode 11-2 includes a transmission electrode 11-2a and a transmission electrode 11-2b. The transmission electrode 11-2a and the transmission electrode 11-2b are electrodes that perform conversion between an electric signal and SAW. Note that the conversion between the electrical signal and the SAW described above is possible in both directions.

  The comb-shaped electrode 11-3 and the comb-shaped electrode 11-4 are metal electrodes formed by a comb-like pattern constituting the reception-side electrode unit. The comb-shaped electrode 11-3 includes a reception electrode 11-3a and a reception electrode 11-3b. The reception electrode 11-3a and the reception electrode 11-3b are electrodes that perform conversion between the SAW and the electric signal. The comb electrode 11-4 includes a reception electrode 11-4a and a reception electrode 11-4b. The reception electrode 11-4a and the reception electrode 11-4b are electrodes that perform conversion between the SAW and the electric signal.

The reaction region thin film 13 is a thin film formed by vapor deposition of gold. The reaction region thin film 13 is a thin film having an antibody supported on the surface. The reaction region thin film 13-1 is formed on the piezoelectric element substrate 10 and between the comb electrode 11-1 and the comb electrode 11-3. The reaction region thin film 13-2 is formed on the piezoelectric element substrate 10 and between the comb electrode 11-2 and the comb electrode 11-4.
A portion where the piezoelectric element substrate 10 and the reaction region thin film 13 overlap becomes a detection region (region serving as a sensor surface) into which a liquid as a specimen is introduced. As described above, in the present application, it is assumed that the detection region is composed of the reaction region thin film 13 and the biofilm fixed on the reaction region thin film 13. This detection region is arranged in the SAW propagation path, and a liquid as a specimen is introduced.

  The convex member 20 holds the droplets of the sample dropped on the plurality of reaction region thin films 13 in the dropped reaction region thin film, and also makes the amount of the sample dropped onto each reaction region thin film 13 constant. It is the convex part provided. The convex member 20 is formed so that the height of the convex portion is several hundred microns or less. The convex member 20-1 and the convex member 20-2 (collectively referred to as the convex portion 20 </ b> A) have a length that is 1/10 or less of the distance d of the reaction region thin film 13. Further, the convex portion 20A is disposed on the outer side (+ Y direction side) of the reaction region thin film 13-1. The convex member 20-3 and the convex member 20-4 (collectively referred to as the convex portion 20B) have a length that is 1/10 or less of the distance d of the reaction region thin film 13. Moreover, the convex part 20B is arrange | positioned between the reaction region thin film 13-1 and the reaction region thin film 13-2. The convex member 20-5 and the convex member 20-6 (collectively referred to as a convex portion 20C) have a length that is 1/10 or less of the distance d of the reaction region thin film 13. Moreover, the convex part 20C is arrange | positioned on the outer side (-Y direction side) of the reaction region thin film 13-2. That is, a plurality of convex members 20 are provided between the reaction region thin film 13-1 and the reaction region thin film 13-2 and outside the reaction region thin film 13-1 and the reaction region thin film 13-2.

  In addition, each structure of 20 A of convex parts, the convex part 20B, and the convex part 20C mentioned above is an example, Comprising: It is not limited to this. For example, the structure shown in FIG. 2 may be used for each of the protrusions 20A, the protrusions 20B, and the protrusions 20C. Hereinafter, other structural patterns of the convex portion 20B will be described. FIG. 2 is a schematic cross-sectional view seen from the cut surface B showing the structure pattern of the convex portion 20B. As shown in FIG. 2A, the structure of the convex portion 20B is sufficient if the upper portion of the convex portion 20B is separated, and the lower portion of the convex portion 20B may be integrally formed. That is, the convex part 20B should just have the groove | channel of predetermined depth in the center part. The width of the groove is not more than 1/10 of the distance d of the reaction region thin film 13. Further, as shown in FIG. 2B, the structure of the convex portion 20B is a step portion (step portion 25, step portion 26, step portion 27) continuous in the Y-axis direction perpendicular to the propagation direction of the surface acoustic wave. ), And the height of the left and right step portions 25 and 27 should be lower than the center step portion 26. Further, as shown in FIG. 2C, the structure of the convex portion 20B has a step portion (step portion 28, step portion 29) having different heights continuous in the Y-axis direction perpendicular to the propagation direction of the surface acoustic wave. ) May be provided in two stages. As described above, the structure of the convex portion 20B has been described with reference to FIG. 2, but it is described that the convex portion 20A and the convex portion 20C can have the same structure as the convex portion 20B shown in FIG. Not too long. Note that the width in the Y-axis direction perpendicular to the propagation direction of the surface acoustic wave in the convex portion 20 is a width in which the specimen liquid is not bonded on the upper surface of the convex portion 20 due to surface tension.

  The convex member 20 may have a structure similar to a sealing structure 14-1 and a sealing structure 14-2, which will be described later, or an epoxy resin used for protection such as wire bonding, or die bonding. For example, a resin (mainly epoxy resin) used for bonding the package and the piezoelectric substrate may be used. Further, unlike the shape and arrangement shown in FIG. 1, the convex member 20 may be formed integrally with the sealing structure 14-1 or the sealing structure 14-2. Alternatively, the convex member 20 may be formed integrally with an external housing made of plastic or the like of the SAW sensor 1 not shown in FIG. Further, the surface of the convex member 20 may be covered with a hydrophobic film or the like in order to prevent the sample liquid from rising above the convex member 20.

The sealing structure 14 is a sealing structure that seals the comb-shaped electrode 11 (excluding the end) from the outside so as to form a space on the comb-shaped electrode 11 and prevents the comb-shaped electrode 11 from coming into contact with the sample liquid. is there. Even if there is a change in the atmosphere (for example, humidity) in the detection region, the comb-shaped electrode 11 is less affected by the sealing structure 14.
The sealing structure 14-1 on the transmission electrode unit side includes a sealing wall 14-1a and a sealing ceiling 14-1b. In addition, although the contact bonding layer for adhere | attaching both is provided between the sealing wall 14-1a and the sealing ceiling 14-1b, it is abbreviate | omitting in FIG.

The sealing wall 14-1 a is a wall that covers the comb electrode 11-1 and the comb electrode 11-2 and is formed in a rectangular shape on the piezoelectric element substrate 10. The sealing wall 14-1a is made of, for example, a photosensitive resin.
The sealing ceiling 14-1b is a ceiling for closing the upper side of the sealing wall 14-1a and sealing the comb electrode 11-1 and the comb electrode 11-2 from the outside. The sealing ceiling 14-1b is disposed on the upper side of the sealing wall 14-1a so that the sealing wall 14-1a fits in the planar area of the sealing ceiling 14-1b. The sealed ceiling 14-1b is made of, for example, a glass substrate. An adhesive layer (not shown) is provided between the sealing wall 14-1a and the sealing ceiling 14-1b, and the space between the sealing wall 14-1a and the sealing ceiling 14-1b is sealed. Glue.

  Further, the sealing structure 14-2 on the reception electrode unit side includes a sealing wall 14-2a and a sealing ceiling 14-2b, similarly to the sealing structure 14-1. The sealing structure 14-2 covers the comb-shaped electrode 11-3 and the comb-shaped electrode 11-4 from outside so as to form a space on the comb-shaped electrode 11-3 and the comb-shaped electrode 11-4. 3 and the comb-shaped electrode 11-4 are sealing structures that prevent the liquid from coming into contact with the liquid.

FIG. 3 is a diagram showing an example when the sample liquid is dropped onto the reaction region thin film 13. FIG. 3A is a diagram showing an example when the specimen liquid is dropped onto the reaction region thin film 13 of the conventional SAW sensor.
FIG. 3B is a diagram illustrating an example when the sample liquid is dropped onto the reaction region thin film 13 of the SAW sensor 1.

  The conventional SAW sensor has a configuration in which one convex member is disposed between the reaction region thin film 13-1 and the reaction region thin film 13-2. For example, the measurer drops the sample liquid A onto the reaction region thin film 13-1 with a micropipette or the like. Further, for example, the measurer drops the sample liquid B different from the sample liquid A onto the reaction region thin film 13-2 with a micropipette or the like. Then, the liquid surfaces of the sample liquids A and B rise due to capillary action and are combined on the upper surface of the convex member 20-3. Thus, the conventional SAW sensor cannot keep the sample liquid constant for each reaction region thin film 13.

  However, as shown in FIG. 3B, in the first embodiment described above, the reaction region thin film 13-1 and the reaction region thin film 13-2 and the reaction region thin film 13-1 and the reaction region thin film 13-2 are included. A plurality of convex members 20 are arranged on the outside. Thereby, even if the liquid surfaces of the sample liquids A and B rise due to the capillary phenomenon, they do not bind on the upper surface of the convex member 20-3 or the convex member 20-4. Therefore, the SAW sensor 1 can prevent the sample liquid A from spreading to a region other than the reaction region thin film 13-1, and can keep the amount of the sample liquid A dropped on the reaction region thin film 13-1. Further, the SAW sensor 1 can prevent the sample liquid B from spreading to a region other than the reaction region thin film 13-2, and can keep the amount of the sample liquid B dropped on the reaction region thin film 13-2 constant. That is, the SAW sensor 1 can hold the sample liquid for each reaction region thin film, and can make the amount of the sample liquid dropped for each reaction region thin film constant.

  In the first embodiment described above, since the surface of the convex member 20 is covered with a hydrophobic film or the like, a large amount of droplets can be retained.

(Second Embodiment)
The second embodiment will be described below with reference to the drawings. FIG. 4 is a schematic diagram of the SAW sensor 1a according to the present embodiment. 4A is a schematic top view of the SAW sensor 1a, and FIG. 4B is a schematic cross-sectional view of the SAW sensor 1a as viewed from the cut surface A. FIG. FIG. 4C is a schematic cross-sectional view of the SAW sensor 1a viewed from the cut surface C. In FIG. 4, the same components as those shown in FIG.

The SAW sensor 1a includes a piezoelectric element substrate 10, a plurality of comb electrodes 11 (comb electrodes 11-1 to 11-4), a plurality of reaction region thin films 13 (13-1, 13-2), and a plurality of sealing structures 14 ( 14-1, 14-2) and convex member 21 (21-1 to 21-6).
The convex member 21 is obtained by extending the length of the convex member 21 of the first embodiment in the + X direction (surface acoustic wave propagation direction) to the lower portion of the sealing structure 14.

The convex member 21-1 and the convex member 21-2 (collectively referred to as the convex portion 21 </ b> A) have a length that is 1/10 or less of the distance d of the reaction region thin film 13 without intersecting each other. Further, the convex portion 21A is arranged on the outer side (+ Y direction side) of the reaction region thin film 13-1. Each of the convex portions 21A intersects the sealing wall 14-1a and the sealing wall 14-2a perpendicularly.
The convex member 21-3 and the convex member 21-4 (collectively referred to as the convex portion 21B) do not intersect with each other, and the distance between them is one tenth or less of the distance d of the reaction region thin film 13. The convex portion 21B is disposed between the reaction region thin film 13-1 and the reaction region thin film 13-2. Further, each of the convex portions 21B intersects the sealing wall 14-1a and the sealing wall 14-2a perpendicularly.
The convex member 21-5 and the convex member 21-6 (collectively referred to as the convex portion 21C) have a distance of 1/10 or less of the distance d of the reaction region thin film 13 without intersecting each other. Moreover, the convex part 21C is arrange | positioned on the outer side (-Y direction side) of the reaction region thin film 13-2. Each of the convex portions 21C intersects the sealing wall 14-1a and the sealing wall 14-2a perpendicularly.

  According to the second embodiment described above, a plurality of convex members are provided between the reaction region thin film 13-1 and the reaction region thin film 13-2 and outside the reaction region thin film 13-1 and the reaction region thin film 13-2. 21 is arranged. Further, each of the plurality of convex members 21 intersects the sealing wall 14-1a and the sealing wall 14-2a perpendicularly. As a result, the same effects as those of the first embodiment can be obtained, and the liquid droplets of the specimen liquid can be accurately retained to the vicinity of the sealing structure 14 for each reaction region thin film as compared with the first embodiment. Can do.

(Third embodiment)
FIG. 5 is a schematic diagram of a SAW sensor 1-1 according to the third embodiment. 5A is a schematic top view of the SAW sensor 1-1, and FIG. 5B is a schematic cross-sectional view of the SAW sensor 1-1 as viewed from the cut surface A. FIG. FIG. 5C is a schematic cross-sectional view of the SAW sensor 1-1 as viewed from the cut surface B. In FIG. 5, the same components as those shown in FIG. 1 or FIG.

  The SAW sensor 1 according to the first embodiment and the SAW sensor 1a according to the second embodiment are SAW sensors called transversal types in which a comb-shaped electrode for transmission and a comb-shaped electrode for reception are separately provided. The SAW sensor 1-1 of the embodiment has a structure called a reflection type. That is, the SAW sensor 1-1 according to the third embodiment is provided with the reflector 30-1 and the reflector 30-2 at a position facing the comb electrode with the detection region interposed therebetween instead of the one comb electrode. . In this configuration, one comb-shaped electrode can be shared for transmission and reception by switching, for example, in a time division manner. Note that the SAW sensor 1-1 of the third embodiment is a two-channel sensor, similar to the SAW sensor 1 of the first embodiment.

  In FIG. 5, the reflector 30-1 reflects the SAW transmitted from the comb electrode 11-1. The reflector 30-1 is disposed at a position facing the comb electrode 11-1 and the reaction region thin film 13-1, and is, for example, one wavelength of SAW using the same electrode material as the comb electrode 11-1. It has a structure in which a plurality of lines are arranged at intervals of a half wavelength with a line width of 1/4. The reflector 30-2 reflects the SAW transmitted from the comb electrode 11-2. The reflector 30-2 is disposed at a position facing the interdigital electrode 11-2 and the reaction region thin film 13-2, and has, for example, the same structure as the reflector 30-1. In the configuration example shown in FIG. 5, the reflector 30-1 and the reflector 30-2 are formed on the piezoelectric element substrate 10 so as to be exposed, and are placed on the reflector 30-1 and the reflector 30-2. Is not provided with a sealing structure like the sealing structure 14-1. In the example shown in FIG. 5, the structure that reflects SAW is configured using a reflector that electrically reflects using electrodes, but the reflection of SAW may be mechanical reflection. For example, a surface acoustic wave can be reflected from the end face of the piezoelectric element substrate 10. That is, the method of reflecting the SAW may be other than installing a reflector.

  According to the third embodiment described above, the SAW sensor 1-1 has the plurality of convex members 20 arranged on the piezoelectric element substrate 10 as in the first embodiment. It is possible to prevent the sample liquid A from dropping in the region other than 1, and to make the amount of the sample liquid A dropped in the reaction region thin film 13-1. Further, the SAW sensor 1 can prevent the sample liquid B from spreading to a region other than the reaction region thin film 13-2, and can keep the amount of the sample liquid B dropped on the reaction region thin film 13-2 constant. That is, the SAW sensor 1 can hold the sample liquid for each reaction region thin film, and can make the amount of the sample liquid dropped for each reaction region thin film constant. Further, since the surface of the convex member 20 is covered with a hydrophobic film or the like, a large amount of droplets can be retained.

(Fourth embodiment)
The fourth embodiment will be described below with reference to the drawings. FIG. 6 is a schematic diagram of the SAW sensor 1-1a according to the present embodiment. 6A is a schematic top view of the SAW sensor 1-1a, and FIG. 6B is a schematic cross-sectional view of the SAW sensor 1-1a as viewed from the cut surface A. FIG. FIG. 6C is a schematic cross-sectional view of the SAW sensor 1-1a as viewed from the cut surface C. In FIG. 6, the same components as those shown in FIG.

The SAW sensor 1-1a includes a piezoelectric element substrate 10, a comb electrode 11-1, a comb electrode 11-2, a plurality of reaction region thin films 13 (13-1, 13-2), a plurality of sealing structures 14-1, and a convex. The member 22 (22-1 to 22-6) is included.
The convex member 22 is obtained by extending the length of the convex member 20 of the third embodiment to the lower part of the sealing structure 14-1.

The convex member 22-1 and the convex member 22-2 (collectively referred to as the convex portion 22A) do not cross each other, and the distance between them is 1/10 or less of the distance d of the reaction region thin film 13. Further, the convex portion 22A is arranged on the outer side (+ Y direction side) of the reaction region thin film 13-1. Each of the convex portions 22A intersects the sealing wall 14-1a perpendicularly.
The convex member 22-3 and the convex member 22-4 (collectively referred to as the convex portion 22B) have a length of 1/10 or less of the distance d of the reaction region thin film 13 without intersecting each other. The convex portion 22B is arranged between the reaction region thin film 13-1 and the reaction region thin film 13-2. Further, each of the convex portions 22B intersects the sealing wall 14-1a perpendicularly.
The convex member 22-5 and the convex member 22-6 (collectively referred to as the convex portion 22C) do not intersect with each other, and the distance between them is one tenth or less of the distance d of the reaction region thin film 13. Moreover, the convex part 22C is arrange | positioned on the outer side (-Y direction side) of the reaction region thin film 13-2. Further, each of the convex portions 22C intersects the sealing wall 14-1a perpendicularly.

  According to the fourth embodiment described above, a plurality of convex members are provided between the reaction region thin film 13-1 and the reaction region thin film 13-2 and outside the reaction region thin film 13-1 and the reaction region thin film 13-2. 22 is arranged. In addition, each of the plurality of convex members 22 intersects the sealing wall 14-1a and the sealing wall 14-2a perpendicularly. As a result, the same effects as those of the first embodiment can be obtained, and the liquid droplets of the specimen liquid can be accurately retained to the vicinity of the sealing structure 14 for each reaction region thin film as compared with the third embodiment. Can do.

(Fifth embodiment)
The fifth embodiment will be described below with reference to the drawings. FIG. 7 is a schematic diagram of the SAW sensor 1-1b according to the present embodiment. 7A is a schematic top view of the SAW sensor 1-1b, and FIG. 7B is a schematic cross-sectional view of the SAW sensor 1-1b as viewed from the cut surface A. FIG. FIG. 7C is a schematic cross-sectional view of the SAW sensor 1-1c as viewed from the cut surface C. In FIG. 7, the same components as those shown in FIG.

  The SAW sensor 1-1b includes a piezoelectric element substrate 10, a comb electrode 11-1, a comb electrode 11-2, a plurality of reaction region thin films 13 (13-1, 13-2), a plurality of sealing structures 14-1, a convex shape. The member 23 (23-1 to 23-6) and the wall part 40 (40-1, 40-2) are included.

The convex member 23-1 and the convex member 23-2 (collectively referred to as the convex portion 23 </ b> A) do not cross each other, and the distance between them is 1/10 or less of the distance d of the reaction region thin film 13. Moreover, the convex part 23A is arrange | positioned on the outer side (+ Y direction side) of the reaction region thin film 13-1. Moreover, as for each of convex part 22A, one cross | intersects perpendicularly to the sealing wall 14-1a, and the other is connected to the wall part 40-1.
The convex member 23-3 and the convex member 23-4 (collectively referred to as the convex portion 23B) do not cross each other, and the distance between them is 1/10 or less of the distance d of the reaction region thin film 13. Moreover, the convex part 23B is arrange | positioned between the reaction region thin film 13-1 and the reaction region thin film 13-2. Further, one of the convex member 23-3 and the convex member 23-4 intersects the sealing wall 14-1a perpendicularly. The other end of the convex member 23-3 is connected to the wall 40-1. The other end of the convex member 23-4 is connected to the wall 40-2.
The convex member 23-5 and the convex member 23-6 (collectively referred to as the convex portion 23C) do not cross each other, and the distance between them is one tenth or less of the distance d of the reaction region thin film 13. Moreover, the convex part 23C is arrange | positioned on the outer side (-Y direction side) of the reaction region thin film 13-2. One of the protrusions 23C intersects the sealing wall 14-1a perpendicularly, and the other is connected to the wall 40-2.

  The wall 40 is provided to hold the droplets of the sample dropped on the plurality of reaction region thin films 13 on the dropped reaction region thin film 13 and prevent the sample from flowing out in the SAW propagation direction. Further, each of the wall portions 40 is bent into a dogleg shape as shown in the figure. Thereby, unnecessary SAW reflected by the wall part 40 can be attenuated.

  According to the fifth embodiment described above, a plurality of convex members are provided between the reaction region thin film 13-1 and the reaction region thin film 13-2 and outside the reaction region thin film 13-1 and the reaction region thin film 13-2. 23 is arranged. Thereby, the effect similar to 1st Embodiment can be acquired.

(SAW sensor drive circuit of the first and second embodiments)
Next, referring to FIG. 8, a circuit for driving and detecting sensors for each channel of the SAW sensor 1-1 of the first embodiment and the SAW sensor 1-1 of the second embodiment (hereinafter referred to as “ A configuration example of a “driving circuit” will be described.

  The drive circuit 100 illustrated in FIG. 8 is a block diagram for explaining a configuration example of the drive circuit 100. The drive circuit 100 includes an oscillator 101, a distributor 102, an elastic wave detector 103, and a processing unit 104.

The oscillator 101 generates a high frequency oscillation signal. The distributor 102 supplies the high-frequency oscillation signal to the comb-shaped electrode 11-1 (or 11-2) and also supplies the elastic wave detector 103.
The acoustic wave detector 103 has an amplitude ratio, a phase difference, and a propagation delay between the high-frequency oscillation signal distributed by the distributor 102 and the signal based on the surface acoustic wave received by the comb electrode 11-3 (or 11-4). The difference is detected, and a signal based on the detected amplitude ratio, phase difference, and propagation delay difference is output to the processing unit 104.
The processing unit 104 obtains the physical characteristics of the object to be measured based on the signal supplied from the elastic wave detector 103. The physical characteristics are, for example, the viscosity and density of the object to be measured. For example, the processing unit 104 obtains an amplitude change and a phase change of the supplied signal in a state where nothing is dropped on the reaction region thin film 13. When nothing is dropped on the reaction region thin film 13, the object to be measured is air. Next, an amplitude change and a phase change of the supplied signal are obtained in a state where an object to be measured is dropped on the reaction region thin film 13. The processing unit 104 calculates the viscosity, density, and the like of the dropped measurement object by calculating these two measurement data.

(Description of operation)
The measurer of the SAW sensor 1 drops the object to be measured on the reaction region thin films 13-1 and 13-2 of the SAW sensor 1. In this case, since the comb electrodes 11-1 and 11-2 are hermetically sealed by the sealing structure 14, there is a situation in which the measurement accuracy deteriorates due to the measurement object attached to the comb electrodes 11-1 and 11-2. It can be avoided. The object to be measured may be a pure liquid or a mixed liquid as long as it is liquid, and is particularly effective when measuring physical properties of alcohols such as methanol and ethanol. . Needless to say, physical properties can be measured even in a state in which an object to be measured includes antigens, antibodies, bacteria, and the like.

Next, the high-frequency oscillation signal generated in a burst manner by the oscillator 101 is distributed by the distributor 102 and the same high-frequency oscillation signal is supplied to the comb electrodes 11-1 and 11-2 and the elastic wave detector 103.
The comb electrodes 11-1 and 11-2 are excited based on the supplied high-frequency oscillation signal to generate an elastic wave. Here, the elastic wave generated by the comb-shaped electrode 11-1 propagates in the surface layer portion of the piezoelectric element substrate 10, and propagates in the arrow X direction along the reaction region thin film 13-1 on which the object to be measured is dropped. The comb-shaped electrode 11-3 receives the elastic wave and converts the received elastic wave into a surface acoustic wave signal.

  The elastic wave generated by the comb electrode 11-2 propagates in the surface layer portion of the piezoelectric element substrate 10 and propagates in the + X direction along the reaction region thin film 13-2 on which the object to be measured is dropped. The comb-shaped electrode 11-4 receives the elastic wave and converts the received elastic wave into a surface acoustic wave signal.

  The surface acoustic waves received by the comb electrodes 11-3 and 11-4 are converted into surface acoustic wave signals and then supplied to the acoustic wave detector 103. The elastic wave detector 103 detects the amplitude ratio, phase difference, and propagation delay difference between the high-frequency oscillation signal supplied from the distributor 102 and the received signal, and the detected amplitude ratio, phase difference, and propagation delay difference. Is output to the processing unit 104. The processing unit 104 obtains physical characteristics of the object to be measured based on these signals supplied from the elastic wave detector 103.

(Drive circuit of SAW sensor of 3rd Embodiment, 4th Embodiment, and 5th Embodiment)
Next, referring to FIG. 9, a circuit for driving and detecting a sensor for each one channel of the SAW sensors of the third embodiment, the fourth embodiment, and the fifth embodiment (hereinafter referred to as “drive circuit”). .) Will be described.

  FIG. 9 is a block diagram for explaining a configuration example of the drive circuit 200. The drive circuit 200 includes an oscillator 101, a distributor 102, an elastic wave detector 103, a processing unit 104A, and a switch 105.

  The processing unit 104A obtains the physical characteristics of the object to be measured based on the signal supplied from the elastic wave detector 103. Further, the processing unit 104 switches the connection between the terminal 1 and the terminal 3 of the switch 105 or the connection between the terminal 2 and the terminal 3 at a predetermined timing. The physical characteristics are, for example, the viscosity and density of the object to be measured. For example, the processing unit 104A obtains the amplitude change and phase change of the supplied signal in a state where nothing is dropped on the reaction region thin film 13. When nothing is dropped on the reaction region thin film 13, the object to be measured is air. Next, an amplitude change and a phase change of the supplied signal are obtained in a state where an object to be measured is dropped on the reaction region thin film 13. The processing unit 104 calculates the viscosity, density, and the like of the dropped measurement object by calculating these two measurement data.

(Description of operation)
The measurer of the SAW sensor 1 drops the object to be measured on the reaction region thin films 13-1 and 13-2 of the SAW sensor 1. In this case, since the comb electrodes 11-1 and 11-2 are hermetically sealed by the sealing structure 14, there is a situation in which the measurement accuracy deteriorates due to the measurement object attached to the comb electrodes 11-1 and 11-2. It can be avoided. The object to be measured may be a pure liquid or a mixed liquid as long as it is liquid, and is particularly effective when measuring physical properties of alcohols such as methanol and ethanol. . Needless to say, physical properties can be measured even in a state in which an object to be measured includes antigens, antibodies, bacteria, and the like.

Next, the high-frequency oscillation signal generated in a burst manner by the oscillator 101 is distributed by the distributor 102 and the same high-frequency oscillation signal is supplied to the comb electrodes 11-1 and 11-2 and the elastic wave detector 103.
The comb electrodes 11-1 and 11-2 are excited based on the supplied high-frequency oscillation signal to generate an elastic wave. Here, the elastic wave generated by the comb-shaped electrode 11-1 propagates in the surface layer portion of the piezoelectric element substrate 10, and propagates in the + X direction along the reaction region thin film 13-1 on which the object to be measured is dropped. Then, after the elastic wave propagated through the reaction region thin film 13-1 is reflected by the reflector 30-1, it becomes a reflected wave, propagates again through the reaction region thin film 13-1, and is received by the comb electrode 11-1. Is done.

  The elastic wave generated by the comb electrode 11-2 propagates in the surface layer portion of the piezoelectric element substrate 10 and propagates in the + X direction along the reaction region thin film 13-2 on which the object to be measured is dropped. Then, after the elastic wave propagated through the reaction region thin film 13-2 is reflected by the reflector 30-2, it becomes a reflected wave, propagates again through the reaction region thin film 13-2, and is received by the comb electrode 11-2. Is done.

  The surface acoustic waves received by the comb electrodes 11-1 and 11-2 are converted into surface acoustic wave signals and then supplied to the acoustic wave detector 103. The elastic wave detector 103 detects the amplitude ratio, phase difference, and propagation delay difference between the high-frequency oscillation signal supplied from the distributor 102 and the received signal, and the detected amplitude ratio, phase difference, and propagation delay difference. Is output to the processing unit 104. The processing unit 104 obtains physical characteristics of the object to be measured based on these signals supplied from the elastic wave detector 103.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 SAW sensor 10 Piezoelectric element board | substrate 11 Comb-shaped electrode 13 Reaction area | region thin film 14 Sealing structure 20, 21, 22, 23 Convex member 30 Reflector 40 Wall part 100 Step part

Claims (7)

A piezoelectric element substrate that propagates a surface acoustic wave;
There are a plurality of channels in the direction perpendicular to the propagation direction, each having an electrode for converting an electric signal and the surface acoustic wave, and a plurality of detection regions arranged in a propagation path of the surface acoustic wave and into which a liquid as an analyte is introduced. A convex member that is provided and is longer than the side facing the adjacent detection region;
A surface acoustic wave sensor.   The surface acoustic wave sensor according to claim 1, wherein the convex member is further provided outside the detection region.   The surface acoustic wave sensor according to claim 1, wherein the convex member is provided with a groove having a predetermined depth in a central portion.   The surface acoustic wave sensor according to claim 3, wherein a width of the groove of the convex member is one tenth or more of a distance of the detection region in a direction perpendicular to a propagation direction of the surface acoustic wave.   The surface acoustic wave sensor according to claim 1, wherein the convex member includes a plurality of step portions having different heights. A sealing structure for preventing the electrode from coming into contact with a liquid;
The surface acoustic wave sensor according to any one of claims 1 to 5, wherein the plurality of convex members extend to the sealing structure without crossing each other.   The surface acoustic wave sensor according to any one of claims 1 to 6, wherein the plurality of convex members have a hydrophobic surface.

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