KR20240073553A - Load cell using nano strain sensor - Google Patents

Abstract

According to one embodiment of the present disclosure, a lower layer, an upper layer including a plurality of silicon blocks coupled to the upper surface of the lower layer and disposed to be spaced apart from each other, and a silicon nano device electrically connecting two adjacent silicon blocks among the plurality of silicon blocks. Provided is a load cell using a nano strain sensor including first to fourth resistance units each including a wire. Therefore, since the nano strain sensor is installed at only one of the several stress generation points of the load cell body, each strain sensor is attached to several stress generation points of the load cell body and wiring is performed between the strain sensors. Compared to the structure, the wiring process is unnecessary, so a highly sensitive load cell can be manufactured simply.

Description

Load cell structure using nano strain sensor {Load cell using nano strain sensor}

The present invention relates to a load cell using a nano strain sensor.

In general, a load cell is a sensor assembly for measuring the load of a target object or an externally applied force (i.e., external force), and uses a strain sensor (also called a 'strain gauge').

In these load cells, when an external force such as the mass of the target object is applied, elastic behavior (a phenomenon in which a deformed object returns to its original state) occurs in the target object, and two or four strain sensors directly correspond to the applied external force. This causes a change in resistance, and at this time, the principle of obtaining data is used by forming an electric circuit called a Wheatstone bridge and converting the change in resistance into a precise electrical signal. In other words, the load cell can be said to be an electrical device that converts changes in load into changes in resistance.

KR 10-1574017 B1

The present disclosure provides a load cell using a nano strain sensor.

A load cell using a nano strain sensor according to the present disclosure includes a body that is deformed by an external force applied through contact with a target object, and a nano strain installed on the body, the resistance of which changes due to stress generated by deformation of the body. May include sensors.

According to one embodiment of the present disclosure, the nano strain sensor includes a lower layer, an upper layer including a plurality of silicon blocks coupled to the upper surface of the lower layer and arranged to be spaced apart from each other, and two adjacent silicon blocks among the plurality of silicon blocks. It may include first to fourth resistors each including silicon nanowires that are electrically connected.

According to one embodiment, the nano strain sensor may be an electric circuit in the form of a Wheatstone bridge.

According to one embodiment, the nano strain sensor may be installed at only one of several stress generation points of the body where stress occurs due to deformation of the body.

According to the embodiment, the silicon nanowires of the first and third resistors may be located on the stress axis of the generated stress and arranged orthogonal to the stress axis.

According to the embodiment, the silicon nanowires of the second and fourth resistance parts may be located at a position outside the stress axis of the generated stress and may be arranged parallel to the stress axis.

According to another embodiment of the present disclosure, the nano strain sensor electrically connects a lower layer, an upper layer including a plurality of silicon blocks coupled to the upper surface of the lower layer and disposed to be spaced apart from each other, and two adjacent silicon blocks among the plurality of silicon blocks. first to fourth resistors each including silicon nanowires and silicon subblocks connected to each other, and the silicon defined by inner sidewalls of each of the plurality of silicon blocks and electrically connecting two adjacent silicon blocks. It may include a diaphragm groove region containing nanowires and silicon subblocks within the region.

According to another embodiment, the nano strain sensor may be an electric circuit in the form of a Wheatstone bridge.

According to another embodiment, the nano strain sensor may be installed at only one of several stress generation points of the body where stress occurs due to deformation of the body.

According to another embodiment, the silicon nanowires of the first and third resistors may be located on the stress axis of the generated stress and arranged parallel to the stress axis.

According to another embodiment, the silicon nanowires of the second and fourth resistance parts may be located at a position outside the stress axis of the generated stress and may be arranged orthogonal to the stress axis.

The features and advantages of the present disclosure will become more apparent from the following detailed description based on the accompanying drawings.

Prior to this, terms or words used in this specification and claims should not be construed in their usual, dictionary meaning, and the inventor may properly define the concept of the term in order to explain his or her invention in the best way. It must be interpreted with meaning and concept consistent with the technical idea of the present invention based on the principle that it is.

According to the present disclosure, since a nano strain sensor containing a silicon nanowire is prefabricated as an electric circuit in the form of a Wheatstone bridge and installed at only one point among several stress generation points of the load cell body, several stress generation points of the load cell body Compared to a structure in which each strain sensor is attached to each strain sensor and wiring is performed between the strain sensors, a wiring process is not necessary, so a highly sensitive load cell can be easily manufactured.

Figure 1 is a perspective view of a nano strain sensor including silicon nanowires according to one embodiment.
FIG. 2 is a circuit diagram showing the arrangement relationship of the first to fourth resistors of the nano strain sensor of FIG. 1.
Figure 3 is a perspective view of a load cell with a nano strain sensor installed.
Figure 4 is a diagram showing a state in which an external force is applied to a load cell on which a nano strain sensor is installed.
FIG. 5 is a diagram showing the stress state of the nano strain sensor according to the application of external force to the load cell of FIG. 4.
FIG. 6 is a graph showing the distribution of stress according to the position of the nano strain sensor of FIG. 5.
Figure 7 is a perspective view of a nano strain sensor including silicon nanowires according to another embodiment.

The objects, advantages, and features of the present disclosure will become more apparent from the following detailed description and preferred embodiments taken in conjunction with the accompanying drawings, but the present disclosure is not necessarily limited thereto. Additionally, in describing the present disclosure, if it is determined that a detailed description of related known technology may unnecessarily obscure the gist of the present disclosure, the detailed description will be omitted.

In assigning reference numerals to components in the drawings, it should be noted that identical components are assigned the same reference numerals as much as possible even if they are shown in different drawings, and similar components are assigned similar reference numerals.

Terms used to describe one implementation of the present disclosure are not intended to limit the disclosure. It should be noted that singular expressions include plural expressions unless the context clearly dictates otherwise.

The drawings may be schematic or exaggerated to illustrate implementations.

In this document, expressions such as “have,” “may have,” “includes,” or “may include” refer to the existence of the corresponding feature (e.g., a numerical value, function, operation, or component such as a part). , and does not rule out the existence of additional features.

Terms such as “one”, “other”, “another”, “first”, “second”, etc. refer to the separation of one component from another. They are used for distinction, and the components are not limited by the above terms.

It should be understood that terms indicating direction, such as up, down, left, right,

The implementation examples described in this document and the accompanying drawings are not intended to limit the disclosure to specific embodiments. This disclosure should be understood to include various modifications, equivalents, and/or alternatives of the embodiments.

Hereinafter, an implementation example according to the present disclosure will be described in detail with reference to the attached drawings.

FIG. 1 is a perspective view of a nano strain sensor 2 including a silicon nanowire 130 according to an embodiment of the present disclosure, and FIG. 2 is a perspective view of the first to fourth resistance parts of the nano strain sensor 2 of FIG. 1. It is a circuit diagram showing the arrangement relationship of (R1 to R4), and Figure 3 is a perspective view of the load cell 300 on which the nano strain sensor 2 is installed.

As shown in FIG. 3, the load cell 300 is installed on a body 1 that is deformed by an external force applied through contact with a target object, and the body 1. It may include a nano strain sensor (2) whose resistance changes due to stress generated by deformation.

As shown in FIG. 1, the nano strain sensor 2 according to one embodiment includes a lower layer 100, a plurality of silicon blocks 110a to d coupled to the upper surface of the lower layer 100 and spaced apart from each other. first to fourth resistors (R1 to R4) each including an upper layer 200 and silicon nanowires 130 electrically connecting two adjacent silicon blocks among the plurality of silicon blocks 110a to d. ) may include.

As described above, the upper layer 200 is formed on the lower layer 100, and the lower layer 100 and the upper layer 200 are electrically insulated.

In addition, silicon nanowires 130 are formed on one surface of the upper layer 200, and at least one silicon nanowire 130 may be formed.

Additionally, the upper layer 200 may include a trench 201 formed between the plurality of silicon blocks 110a to d to space the plurality of silicon blocks 110a to d apart from each other.

Meanwhile, as can be seen in FIGS. 1 and 2, the nano strain sensor 2 according to one embodiment includes first to fourth resistance units (R1 to R4) and may be an electric circuit in the form of a Wheatstone bridge. there is.

The first to fourth resistors R1 to R4 may be set to the same resistance, but as shown in FIG. 2, the first and third resistors R1 and R3 become variable resistors, and the second and third resistors R1 to R4 become variable resistors. The fourth resistance units (R2, R4) may be fixed resistors.

However, although not shown, the first and third resistors R1 and R3 become fixed resistors depending on the location or direction of the external force applied to the load cell 300 or the installation location of the nano strain sensor 2, The second and fourth resistors R2 and R4 may be variable resistors.

As shown in FIG. 1, the plurality of silicon nanowires 130 are connected in parallel and arranged between the silicon blocks 110a to d to be affected by stress generated by deformation of the body 1. You can.

Additionally, the nano strain sensor 2 may be installed at only one point (P) among several stress generation points of the body 1 where stress is generated due to deformation of the body 1.

As shown in FIG. 1, the silicon blocks 110a to 110d are located one in each quadrant when the upper layer 200 is divided into quadrants.

Accordingly, four rectangular silicon blocks 110a to 110d that are electrically insulated from each other are formed, and the boundary of the quadrants is formed by a trench 201. Additionally, as the trench 201 is formed, the silicon blocks 110a to 110d may be insulated.

As described above, a trench 201 is formed between the silicon blocks 110a ~ d to electrically insulate the silicon blocks 110a ~ d from each other, but the plurality of silicon blocks 110a ~ d are formed between the first to They can be electrically connected to each other only through the fourth resistance portions (R1 to R4).

As shown in FIG. 1, the silicon nanowires 130 of the first and third resistance parts (R1, R3) are located on the stress axis (SA) of the generated stress and are perpendicular to the stress axis (SA). When arranged so as to do so, the first and third resistance parts R1 and R3 may respond sensitively to stress.

In addition, when the silicon nanowires 130 of the second and fourth resistance parts (R2, R4) are located at a position outside the stress axis (SA) of the generated stress and are arranged parallel to the stress axis (SA) , the second and fourth resistance units R2 and R4 may respond insensitively to stress.

Therefore, since the nano strain sensor 2 according to an embodiment of the present disclosure as described above is manufactured in advance as an electric circuit in the form of a Wheatstone bridge and installed at only one of several stress generation points of the load cell body, the load cell body Compared to a structure in which each strain sensor is attached to various stress generation points and wiring is performed between the strain sensors, a high-sensitivity load cell can be easily manufactured because the wiring process is not necessary.

FIG. 4 is a diagram illustrating a state in which an external force is applied to the load cell 300 on which the nano strain sensor 2 of FIG. 1 is installed as described above. FIG. It shows the change in stress transmitted to the nano strain sensor 2 installed at any one of several stress generation points of the load cell 300 due to the behavior of the load cell 300.

FIG. 5 is a diagram showing the stress state of the nano strain sensor 2 according to the application of external force to the load cell 300 of FIG. 4, and shows the stress state of the nano strain sensor 2 caused by the behavior of the load cell 300 as described above. It shows a state in which the change in stress that causes the change in resistance appears only in the first and third resistance parts (R1, R3).

In addition, FIG. 6 is a graph showing the distribution of stress according to the position of the nano strain sensor 2 of FIG. 5, where the nano strain sensor 2 installed at any one of several stress generation points of the load cell 300 It shows the stresses of the first and third resistance parts (R1, R3) and the stresses of the second and fourth resistance parts (R2, R4).

That is, as can be seen in the graph of FIG. 6, the silicon nanowires 130 of the first and third resistance parts R1 and R3 are located on the stress axis SA of the generated stress and the stress axis When arranged orthogonally to (SA) (see FIG. 5), the first and third resistance parts (R1, R3) are sensitive to stress as indicated by the marks (■, ▲) at the top of the graph. Able to know.

In addition, as can be seen in the graph of FIG. 6, the silicon nanowires 130 of the second and fourth resistance parts R2 and R4 are located at a position outside the stress axis SA of the generated stress and the When arranged parallel to the stress axis SA (see FIG. 5), the second and fourth resistance parts R2 and R4 react insensitively to stress as indicated by the marks (●, ▼) at the bottom of the graph. You can see that there is.

Hereinafter, other implementation examples according to the present disclosure will be described in detail.

Figure 7 is a perspective view of a nano strain sensor 2 including silicon nanowires 130 according to another embodiment of the present disclosure.

Meanwhile, the nano strain sensor 2 according to another embodiment of FIG. 7 can also be installed on the body 1 that is deformed by external force applied through contact with the target object in the load cell 300 shown in FIG. 3. there is.

As shown in FIG. 7, the nano strain sensor 2 according to another embodiment includes a lower layer 100, a plurality of silicon blocks 110a to d coupled to the upper surface of the lower layer 100 and spaced apart from each other. First to fourth layers each including an upper layer 200, silicon nanowires 130 and silicon subblocks 140 that electrically connect two adjacent silicon blocks among the plurality of silicon blocks 110a to 110d. The silicon nanowire 130 defined by the resistance portions R1 to R4 and the inner side walls 111 of each of the plurality of silicon blocks 110a to d, and electrically connecting two adjacent silicon blocks, and It may include a diaphragm groove region 202 including the silicon subblock 140 within the region.

As described with reference to FIG. 1 , in FIG. 7 an upper layer 200 is formed on the lower layer 100, and the lower layer 100 and the upper layer 200 are electrically insulated.

Meanwhile, while the plurality of silicon blocks 110a to d in FIG. 1 have a square shape, the plurality of silicon blocks 110a to d in FIG. 7 each have a rectangular shape. It has a shape.

In addition, like the nano strain sensor 2 of FIG. 1, the nano strain sensor 2 according to another embodiment of FIG. 7 also includes first to fourth resistors (R1 to R4) and has a Wheatstone bridge type. It could be an electrical circuit.

Additionally, the first to fourth resistors R1 to R4 in FIG. 7 may also be set to the same resistance, but the first and third resistors R1 and R3 become variable resistors, and the second and fourth resistors Parts (R2, R4) can be fixed resistors.

However, although not shown, the first and third resistors R1 and R3 become fixed resistors depending on the location or direction of the external force applied to the load cell 300 or the installation location of the nano strain sensor 2, The second and fourth resistors R2 and R4 may be variable resistors.

Additionally, as shown in FIG. 7, the plurality of silicon nanowires 130 may be connected in parallel and disposed in the diaphragm groove area to be affected by stress generated by deformation of the body 1.

Like FIG. 1 , the nano strain sensor 2 of FIG. 7 may also be installed at only one point (P) among several stress generation points of the body 1 where stress occurs due to deformation of the body 1 .

As shown in FIG. 7, the silicon blocks 110a to 110d are located one in each quadrant when the upper layer 200 is divided into quadrants.

thus, Four silicon blocks 110a to 110d that are electrically insulated from each other are formed, and the boundary of the quadrants is formed by a trench 201. Additionally, as the trench 201 is formed, the silicon blocks 110a to 110d may be insulated.

As in FIG. 1, a trench 201 is formed between the plurality of silicon blocks 110a to 7 shown in FIG. 7 to electrically insulate the silicon blocks 110a to 7 from each other. (110a~d) may be electrically connected to each other only with the first to fourth resistance units (R1~R4).

For example, in the first resistance portion R1 of FIG. 7, the silicon nanowire 130 is like a bridge between two adjacent silicon blocks 110a and 110b and one silicon subblock 140. By being formed in a connected form, the two adjacent silicon blocks 110a and 110b can be electrically connected to each other through the silicon nanowire 130 and the silicon subblock 140.

Likewise, in each of the second to fourth resistor parts R2 to R4 of FIG. 7, as in the first resistor part R1, silicon nanowires are connected between two adjacent silicon blocks and one silicon subblock. By being formed in a bridge-like connection form, two adjacent silicon blocks can be electrically connected to each other through silicon nanowires and silicon subblocks.

In addition, the nano strain sensor 2 of FIG. 7 is different from the nano strain sensor 2 of FIG. 1 in that the boundary of the quadrant is formed by a trench 201, while each of the plurality of silicon blocks 110a to d It further includes a diaphragm groove region 202 defined by inner sidewalls 111 and within that region the silicon nanowire 130 and the silicon subblock 140 that electrically connect two adjacent silicon blocks. can do.

The diaphragm groove area 202 can be formed by etching the center of the other side of the upper layer 200 based on the first to fourth resistance parts R1 to R4, since the formation process is a well-known technology well known to those skilled in the art. , the detailed description is omitted.

As described above, in the nano strain sensor 2 of FIG. 7, each silicon nanowire 130 of each of the first and third resistance parts R1 and R3 is located in a quadrant based on the center of the upper layer 200. As they are spaced apart from each other to be located at the boundary, the first and third resistance parts (R1, R3) electrically connect two adjacent silicon blocks, and each of the first and third resistance parts (R1, R3) electrically connects the two adjacent silicon blocks. Two adjacent silicon blocks connected by do not overlap. That is, the first and third resistance parts R1 and R3 may be formed to face each other without overlapping.

In addition, in the nano strain sensor 2 of FIG. 7, the second and fourth resistance parts R2 and R4 are perpendicular to the direction in which the first and third resistance parts R1 and R3 are spaced apart from the upper layer 200. They are spaced apart from each other around the center of the upper layer 200 and are located at the quadrant boundary. Like the first and third resistors R1 and R3, the second and fourth resistors R2 and R4 electrically connect two adjacent silicon blocks, and each of the second and fourth resistors ( Two adjacent silicon blocks electrically connected by (R2, R4) do not overlap. That is, the second and fourth resistance parts R2 and R4 may be formed to face each other without overlapping.

Meanwhile, unlike the nano strain sensor 2 of FIG. 1 described above, the silicon nanowire 130 of the first and third resistance parts R1 and R3 shown in FIG. 7 has a stress axis ( When located on SA) and parallel to the stress axis SA, the first and third resistance parts R1 and R3 may respond insensitively to stress.

In addition, unlike the nano strain sensor 2 of FIG. 1 described above, the silicon nanowires 130 of the second and fourth resistance parts R2 and R4 shown in FIG. 7 are different from the stress axis of the generated stress ( When located at a position outside SA and perpendicular to the stress axis SA, the second and fourth resistance parts R2 and R4 may react sensitively to stress.

As above, the sensitivity to stress of the first and third resistance parts (R1, R3) and the second and fourth resistance parts (R2, R4) according to the location and direction of stress generation explained with reference to FIG. 7 is This appears opposite to the sensitivity to stress of the first and third resistance units (R1, R3) and the second and fourth resistance units (R2, R4) depending on the location and direction of stress generation previously described with reference to FIG. 1. Able to know.

That is, the first and third resistance parts (R1, R3) of FIG. 1 react sensitively to stress, while the first and third resistance parts (R1, R3) of FIG. 7 react insensitively to stress. .

In addition, while the second and fourth resistance parts R2 and R4 of FIG. 1 are insensitive to stress, the second and fourth resistance parts R2 and R4 of FIG. 7 are sensitive to stress. .

Accordingly, although not shown, the distribution of stress according to the position and direction of the nano strain sensor in FIG. 7 appears to be the opposite of the distribution of stress according to the position and direction of the nano strain sensor in FIG. 1 (see the graph in FIG. 6). You will find out.

Therefore, like the above embodiment, the nano strain sensor 2 according to another embodiment of the present disclosure is manufactured in advance as an electric circuit in the form of a Wheatstone bridge and installed at only one of several stress generation points of the load cell body. , Compared to a structure in which each strain sensor is attached to various stress generation points of the load cell body and wiring is performed between the strain sensors, the wiring process is unnecessary, so a highly sensitive load cell can be easily manufactured.

The present disclosure has been described in detail above through specific implementation examples. The implementation examples are for specifically explaining the present disclosure, and the present disclosure is not limited thereto. It will be clear that modifications and improvements can be made by those skilled in the art within the technical spirit of the present disclosure.

All simple modifications or changes to the present disclosure fall within the scope of the present disclosure, and the specific scope of protection of the present disclosure will be made clear by the appended claims.

1: Body 2: Nano Strain Sensor
100: lower layer 110a ~ d: silicon block
111: inner side wall 130: silicon nanowire
140: Silicon subblock 200: Upper layer
201: trench 202: diaphragm groove area
300: Load cells R1 to R4: first to fourth resistance units
SA: stress axis

Claims (11)

A body deformed by an external force applied through contact with a target object; and
A load cell using a nano strain sensor, which is installed on the body and includes a nano strain sensor whose resistance changes due to stress generated by deformation of the body. In claim 1,
The nano strain sensor is
lower layer;
an upper layer coupled to the upper surface of the lower layer and including a plurality of silicon blocks arranged to be spaced apart from each other; and
A load cell using a nano strain sensor, comprising first to fourth resistors each including silicon nanowires electrically connecting two adjacent silicon blocks among the plurality of silicon blocks. In claim 2,
The nano strain sensor is a load cell using a nano strain sensor, which is an electric circuit in the form of a Wheatstone bridge. In claim 2,
A load cell using a nano strain sensor, wherein the nano strain sensor is installed at only one of several stress generation points of the body where stress occurs due to deformation of the body. In claim 2,
A load cell using a nano strain sensor, wherein the silicon nanowires of the first and third resistors are located on the stress axis of the generated stress and are arranged orthogonal to the stress axis. In claim 2,
A load cell using a nano strain sensor, wherein the silicon nanowires of the second and fourth resistors are located at a position outside the stress axis of the generated stress and are arranged parallel to the stress axis. In claim 1,
The nano strain sensor is
lower layer;
an upper layer coupled to the upper surface of the lower layer and including a plurality of silicon blocks arranged to be spaced apart from each other;
First to fourth resistors each including silicon nanowires and silicon subblocks electrically connecting two adjacent silicon blocks among the plurality of silicon blocks; and
Using a nano strain sensor, including a diaphragm groove region defined by the inner sidewalls of each of the plurality of silicon blocks and including the silicon nanowires and silicon subblocks in the region electrically connecting two adjacent silicon blocks. load cell. In claim 7,
The nano strain sensor is a load cell using a nano strain sensor, which is an electric circuit in the form of a Wheatstone bridge. In claim 7,
A load cell using a nano strain sensor, wherein the nano strain sensor is installed at only one of several stress generation points of the body where stress occurs due to deformation of the body. In claim 7,
A load cell using a nano strain sensor, wherein the silicon nanowires of the first and third resistors are located on the stress axis of the generated stress and arranged parallel to the stress axis. In claim 7,
A load cell using a nano strain sensor, wherein the silicon nanowires of the second and fourth resistors are located at a position outside the stress axis of the generated stress and are arranged orthogonal to the stress axis.

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