Paper-based gravity measurer and preparation method thereof

Abstract

The invention belongs to the technical field of electronic equipment, and particularly relates to a paper-based gravity measurer and a preparation method thereof. The paper-based gravity measurer comprises a measurer shell, a substrate layer, a gravity measuring module, a circuit module and a display module. The measurer shell is made of organic glass, the substrate layer is selected from white cardboard, kraft paper, coated paper and offset paper, and the gravity measurement module comprises a graphite resistor, conductive silver paste and copper foil; the combination of the copper foil, the conductive silver paste and the graphite resistor is adopted to replace a high-temperature and high-pressure printed conductive silver paste circuit, so that the problem of failure of the substrate layer can be solved, the measurement range of the paper-based gravity measurer is wider, the preparation process is more simplified, and the preparation cost is further reduced; the paper-based gravity measurer manufactured by the invention is low in cost, light in weight, portable, simple in preparation process, simple and easy to debug, easy for large-scale industrial production and education popularization, and has a good application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic equipment, and in particular relates to a paper-based gravimeter and a preparation method thereof. Background Art

[0002] Flexible devices can achieve friendly interactions with humans and have a wide range of applications in medicine and biology. Traditional CMOS technology uses Si as a substrate material, but the original Si substrate is not flexible. In order to achieve flexibility, chemical mechanical polishing is used to reduce the Si substrate to a submicron thickness, but this method is challenging and costly. Although polymer materials can be used as flexible substrates, the cost of these materials is still relatively high. In addition, the manufacturing process needs to be completed in a clean room. Complex processes and strict environmental conditions are the main factors limiting the application of flexible devices. Therefore, it is urgent to seek new substrate materials and develop new processes to manufacture flexible devices.

[0003] As researchers delve deeper into flexible device research, a variety of new materials are being used to create flexible device substrates. Paper, due to its flexibility, minimal cost, and lightweight properties, is considered readily adaptable for flexible devices such as paper-based acoustic sources and microfluidic systems. Pencils, as widely used writing tools, offer the advantages of easy availability and low cost. The primary component of pencil lead is graphite, which is stable, and the traces left on paper can realize the functions of flexible electronic devices.

[0004] However, how to combine ordinary paper and pencils to make a low-cost gravity meter with a wide measurement range is a technical problem that needs to be solved urgently. Summary of the Invention

[0005] In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides a paper-based gravimeter and a preparation method thereof, so as to increase its measuring range and reduce production costs.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A first aspect of the present invention provides a paper-based gravity measuring device, comprising: a measuring device housing, a base layer, a gravity measurement module, a circuit module and a display module; the base layer and the gravity measurement module are located in the measuring device housing; the gravity measurement module is laid on the upper surface of the base layer; the circuit module is electromechanically connected to the gravity measurement module via an alligator clip; and the display module is electromechanically connected to the circuit module via a DuPont wire.

[0008] Preferably, the base layer is made of any one of white cardboard, kraft paper, coated paper, and offset paper.

[0009] Preferably, the circuit module includes an analog-to-digital conversion circuit, a data processing circuit, a data acquisition circuit, a power supply circuit, and a power supply step-down circuit.

[0010] Preferably, the housing of the measuring device is made of organic glass.

[0011] Preferably, the gravity measurement module includes a graphite resistor, a conductive silver paste and a copper foil.

[0012] A second aspect of the present invention provides a method for preparing a paper-based gravimeter, which simplifies the preparation process of the paper-based gravimeter while ensuring that its measurement range remains unchanged and the cost does not increase, so as to facilitate large-scale industrial production. The method comprises the following steps:

[0013] (1) Use a utility knife to cut out a rectangular piece of paper of specified size from white cardboard, kraft paper, coated paper or offset paper as the base layer;

[0014] (2) preparing a gravity measurement module on the upper surface of the substrate using graphite, copper foil, and conductive silver paste;

[0015] (3) Use alligator clips to electromechanically connect the circuit module to the gravity measurement module;

[0016] (4) Use DuPont wire to electromechanically connect the display module and the circuit module;

[0017] (5) Place the gravity measurement module and the base layer into the measuring device housing.

[0018] Preferably, the method for preparing the gravity measurement module comprises the following steps:

[0019] Step S1: Draw a rectangle of specified size in the center of the base layer, which serves as the load-bearing plate;

[0020] Step S2: Draw a rectangle of specified size on the border of the base layer to form the cantilever arm, and repeat this operation on the four borders of the base layer;

[0021] Step S3: Use a utility knife to cut out the paper pieces except for the frame, the load-bearing plate, and the cantilever arm from the base layer;

[0022] Step S4: repeatedly using a pencil to draw graphite marks of a fixed size at the corresponding position of the cantilever arm, and stacking a certain number of graphite marks into a graphite resistor;

[0023] Step S5: Use a utility knife to cut out copper foil of a fixed size and shape, and stick the narrow part of the copper foil on the paper just in contact with the graphite resistor. Repeat this operation on the four cantilever arms;

[0024] Step S6: Use a conductive silver paste pen to drip conductive silver paste at the contact point between the copper foil and the graphite resistor, repeat this operation for the four cantilever arms, and dry until the silver paste solidifies;

[0025] Step S7: Place the base layer and the gravity measurement module into the sensor housing, expose the copper foil, and fix it with a fish-tail clip.

[0026] Preferably, the sizes of the white cardboard, kraft paper, coated paper, and offset paper are A4.

[0027] Preferably, the size of the base layer is 137 mm × 137 mm.

[0028] Preferably, the size of the bearing plate is 28 mm × 28 mm.

[0029] Preferably, the size of the cantilever beam is 40.5 mm × 7.7 mm.

[0030] Preferably, in step S4, the number of layers of the graphite trace is 60; the graphite resistor is in a "ji" shape, and the size of the graphite resistor is 7 mm × 5 mm.

[0031] Preferably, in step S5, the shape of the copper foil consists of two rectangles with different sizes, and the sizes are 11 mm × 3 mm and 14 mm × 12 mm respectively.

[0032] Preferably, in step S6, the diameter of the conductive silver paste is 1.5 mm - 3 mm, the drying temperature is 30 - 45 °C, the drying time is 10 minutes, and the drying atmosphere is air.

[0033] The third aspect of the present invention provides an application of a paper-based gravity measurer in an actual measuring device.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] A paper-based gravity measurer provided in this application includes a measurer housing, a base layer, a gravity measurement module, a circuit module, and a display module. The material of the measurer housing is plexiglass, the base layer is selected from white cardboard, kraft paper, coated paper, or offset paper, and the gravity measurement module includes a graphite resistor, a conductive silver paste, and a copper foil; this application uses the combination of the copper foil, the conductive silver paste, and the graphite resistor to replace the high-temperature and high-pressure printed conductive silver paste circuit, which can solve the problem of base layer failure, make the measurement range of the paper-based gravity measurer wider, lightweight and portable, and easy to debug; the preparation process is more simplified, the preparation cost is further reduced, it is easy for large-scale industrial production and educational popularization, and has good application prospects.

[0036] Specifically, it is mainly reflected in the following aspects:

[0037] (1) The conductivity of the graphite resistor will change when the graphite resistor is prepared with different numbers of graphite trace layers. When the length of the graphite resistor is kept constant and the graphite content is kept constant, when the number of graphite trace layers is greater than 50, the conductivity of the graphite resistor will remain almost unchanged, and the resistance value of the graphite resistor will also remain unchanged. The present application uses 60 layers of graphite traces to prepare the graphite resistor, thereby minimizing the error caused by artificial preparation of the graphite resistor, optimizing the output data of the paper-based gravimeter, simplifying the experimental conditions, and optimizing the preparation process.

[0038] (2) The friction coefficients of the base layer materials described in this application are different, and the resistance values of the graphite resistors prepared on their surfaces are different. The friction coefficients are kraft paper > white cardboard > offset paper > coated paper. The lower the friction coefficient, the harder it is for a pencil to leave graphite marks on its surface, and thus the more difficult it is to prepare a graphite resistor. The toughness coefficients of the base layer materials are different, and the degree of plastic deformation due to the weight of the heavy object is different, and thus the effective measurement range and effective measurement times of the prepared paper-based gravimeter are different. Taking into account the effective measurement times and effective measurement range of the paper-based gravimeter and the difficulty of preparing the graphite resistor, this application uses white cardboard as the base layer material.

[0039] (3) The resistance of the graphite resistor described in this application changes when subjected to pressure, and the change in resistance is linearly related to the pressure. Furthermore, the resistance change of graphite resistors made from pencils with different graphite contents when subjected to pressure cannot maintain a stable linear relationship with the magnitude of the pressure. The graphite resistors made from pencils with a graphite content of 60%-70% in this application maintain the most stable linear relationship, and the gravity measurement data output by the paper-based gravimeter is the most accurate.

[0040] (4) After measuring the gravity of a heavy object a certain number of times, the base layer undergoes plastic deformation, resulting in fatigue, and the output data error of the paper-based gravimeter is too large. The present invention adopts the gravity measurement module and the base layer to be placed in the measuring device housing to reduce the degree of deformation of the base layer during use and alleviate fatigue.

[0041] (5) The density of the graphite resistor described in this application has a certain limit. When the pressure on the graphite resistor exceeds this limit, the resistance value of the graphite resistor becomes unpredictable and accurate gravity measurement data cannot be output.

[0042] (6) The present applicant discovered that a high-temperature and high-pressure printed gravity measurement module would cause the base layer to fail. The present invention uses a combination of the copper foil, the conductive silver paste, and the graphite resistor to replace the high-temperature and high-pressure printed conductive silver paste circuit, which can solve the problem of base layer failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Schematic diagram of the upper surface structure of the paper-based gravimeter provided in an embodiment of the present application.

[0044] Figure 2 This is a schematic side structural diagram of the paper-based gravimeter provided in an embodiment of the present application.

[0045] Figure 3 This is a schematic diagram of the gravity of an object and the change in resistance value of the paper-based gravity meter provided in an embodiment of the present application.

[0046] Figure 4 Schematic diagram of the tension and resistance of the cantilever arm provided in an embodiment of the present application.

[0047] Figure 5 This is a schematic diagram of the resistance of the graphite resistor provided in the embodiment of the present application with different numbers of layers.

[0048] Figure 6 This is a schematic diagram of the object gravity and resistance change of the paper-based gravimeter provided in an embodiment of the present application when the sensor housing is removed.

[0049] Figure 7 Schematic diagram of the gravity of an object and the change in resistance (beyond the effective range of the measuring device) borne by the paper-based gravity measuring device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0050] The following is a further description of specific embodiments of the present invention. It should be noted that the description of these embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0051] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.

[0052] refer to Figure 1 、 Figure 2 An embodiment of the present application provides a paper-based gravity measuring device, comprising: a measuring device housing 1, a base layer 2, a gravity measurement module 3, a circuit module 4, and a display module 5; wherein the base layer 2 and the gravity measurement module 3 are placed in the measuring device housing 1; the gravity measurement module 3 is laid on the upper surface of the base layer 2; the circuit module 4 is electromechanically connected to the gravity measurement module 3 through an alligator clip; and the display module 5 is electromechanically connected to the circuit module 4 through a DuPont wire.

[0053] Furthermore, the base layer of this embodiment may be made of any one of white cardboard, kraft paper, coated paper, and offset paper.

[0054] Furthermore, the gravity measurement module of this embodiment is made of copper foil, conductive silver paste and graphite.

[0055] Furthermore, the housing of the measuring device in this embodiment is made of organic glass.

[0056] Example 1

[0057] A method for preparing a paper-based gravimeter comprises the following steps:

[0058] (1) Draw a rectangle of specified size anywhere on white cardboard and cut it with a utility knife;

[0059] (2) Draw a rectangle of specified size in the center of the base layer, which serves as the load-bearing plate;

[0060] (3) Draw a rectangle of specified size on the border of the base layer and repeat it once on all four sides of the load-bearing plate to form the cantilever arm;

[0061] (4) Using a utility knife, cut the white cardboard from the rectangular paper except for the frame, the load-bearing plate, and the cantilever arm to form the base layer;

[0062] (5) Use a pencil to draw a graphite resistor of fixed size at the corresponding position of the cantilever arm, and stick the narrow part of the copper foil on the paper just in contact with the graphite resistor;

[0063] (6) Use a conductive silver paste pen to drip conductive silver paste on the contact point, repeat this operation for the four cantilever arms, and dry until the silver paste solidifies;

[0064] (7) Place the base layer and gravity measurement module into the measuring device housing, expose the copper foil, and fix it with fishtail clips;

[0065] (8) Use alligator clips to electromechanically connect the circuit module to the gravity measurement module;

[0066] (9) Use DuPont wire to electromechanically connect the display module and the circuit module;

[0067] In this embodiment, the areas of the base layer 2 and the gravity measurement module 3 are set according to actual needs, and the gravity measurement module 3 needs to be entirely disposed on the upper surface of the base layer 2 .

[0068] In this embodiment, the area of the measuring device housing 1 is set according to actual needs. The area of the base layer 2 and the gravity measurement module 3 placed in the measuring device housing 1 is not specifically limited, and only 1 / 4-1 / 2 of the area of the gravity measurement module needs to be exposed.

[0069] In this embodiment, the base layer has a size of 137 mm×137 mm.

[0070] In this embodiment, the bearing plate has a size of 28 mm×28 mm.

[0071] In this embodiment, the cantilever arm has a size of 40.5 mm×7.7 mm.

[0072] In this embodiment, the gravity measurement module consists of the graphite resistor, the copper foil, and the conductive silver paste. The graphite resistor is in the shape of a "J" and measures 7mm x 5mm. The copper foil consists of two rectangular shapes of different sizes, measuring 11mm x 3mm and 14mm x 12mm respectively. The conductive silver paste has a diameter of 1.5mm to 3mm.

[0073] In this embodiment, the drying step (6) is performed at a temperature of 30-45°C for 10 minutes in an air atmosphere.

[0074] In this embodiment, the paper-based gravimeter can be considered to be composed of four cantilever arms.

[0075] Experimental Example 1

[0076] The paper-based gravimeter of Example 1 was tested for relevant performance within the measurement limit, and the test results are as follows: Figure 3 It can be seen that the object's gravity and the change in the graphite resistor's resistance value show a stable linear relationship between 0-1000N. The circuit module is used to collect data, perform analog-to-digital conversion, and perform formula calculations, and finally output to the user using the display module. Figure 4 The change of the pulling force and resistance value of the cantilever arm in this embodiment is as follows: Figure 4 It can be seen that the tension on the cantilever arm is linearly related to the change in resistance. Since the paper-based gravimeter is composed of the cantilever arm, in order to expand the measuring range, four cantilever arms are combined in an axisymmetric form to form a paper-based gravimeter. Figure 5 The resistance values of the graphite resistors with different numbers of layers in this embodiment are shown in Table 1. Figure 5 It can be seen that when the length and width of the graphite resistor remain consistent, the resistance value remains basically stable after the number of graphite trace layers is greater than 50. Therefore, a gravity measurement module can be formed using a graphite resistor with a thickness of more than 50 layers. Figure 6 Schematic diagram of the object gravity and resistance change of the paper-based gravimeter provided in the embodiment of the present application when the sensor housing is removed. Figure 6 It can be seen that when the weight of the object exceeds 600N, the change in the resistance of the graphite resistor is no longer linearly related to the weight. Removing the sensor housing reduces the rigidity of the substrate layer and increases its plastic deformation. Therefore, the range within which the relationship between the weight of the object and the change in the resistance of the graphite resistor is linearly related is much smaller than when the sensor housing is included, resulting in a reduced measurement range. Figure 7This is a graph showing the results of relevant performance testing of the paper-based gravimeter described in this embodiment outside the measurement limit. It can be seen that when the measurement limit is outside, the gravity of the object and the change in the resistance value of the graphite resistor are not linearly related, and therefore it cannot be used for measurement. The effective measurement range of the paper-based gravimeter is 0-1000N.

[0077] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. It is apparent to those skilled in the art that various changes, modifications, substitutions, and variations of these embodiments may be made without departing from the principles and spirit of the present invention, and the changes still fall within the scope of protection of the present invention.

Claims

1. A paper-based gravimeter, characterized in that: Including: A measurer housing, a base layer, a gravity measurement module, a circuit module, and a display module; the base layer and the gravity measurement module are located inside the measurer housing; the gravity measurement module is laid on the upper surface of the base layer; the circuit module is mechanically and electrically connected to the gravity measurement module; the display module is mechanically and electrically connected to the circuit module.

2. A paper-based gravimeter according to claim 1, characterized in that: The material of the base layer is any one of white cardboard, kraft paper, coated paper, and offset paper.

3. A paper-based gravimeter according to claim 1, characterized in that: The material of the measurer housing is plexiglass.

4. A paper-based gravimeter according to claim 1, characterized in that: The gravity measurement module includes graphite resistors, conductive silver paste, and copper foil.

5. A method for preparing a paper-based gravimeter according to any one of claims 1 to 4, characterized in that: Including the following steps: (1) Cut out a rectangular piece of paper with a specified size as the base layer. (2) Use graphite, copper foil, and conductive silver paste to prepare a gravity measurement module on the upper surface of the base layer. (3) Mechanically and electrically connect the circuit module to the gravity measurement module. (4) Mechanically and electrically connect the display module to the circuit module. (5) Place the gravity measurement module and the base layer into the measurer housing.

6. The method for preparing a paper-based gravimeter according to claim 5, characterized in that: The preparation method of the gravity measurement module includes the following steps: Step S1: Draw a rectangle with a specified size in the center of the base layer as the bearing plate. Step S2: Draw a rectangle with a specified size on the border of the base layer as the cantilever beam, and repeat this operation on the four borders of the base layer. Step S3: Cut out the paper on the base layer except for the border, bearing plate, and cantilever beam. Step S4: Repeatedly use a pencil to draw graphite traces with a fixed size at the corresponding positions of the cantilever beams, and stack a certain number of layers of graphite traces to form a graphite resistor. Step S5: Cut out a copper foil with a fixed size and shape, and paste the narrow part of the copper foil on the paper just to contact the graphite resistor, and repeat this operation on the four cantilever beams. Step S6: Drop conductive silver paste at the contact points between the copper foil and the graphite resistor with a conductive silver paste pen, repeat this operation on the four cantilever beams, and dry until the silver paste is cured. Step S7: Place the base layer and the gravity measurement module into the sensor housing, expose the copper foil, and fix it with a fish tail clip.

7. The method for preparing a paper-based gravimeter according to claim 6, characterized in that: The size of the base layer is 137mm×137mm, the size of the bearing plate is 28mm×28mm, and the size of the cantilever beam is 40.5mm×7.7mm.

8. The method for preparing a paper-based gravimeter according to claim 6, characterized in that: In step S4, the number of layers of the graphite traces is 60; the graphite resistor is in a "few" shape, and the size of the graphite resistor is 7mm×5mm.

9. The method for preparing a paper-based gravimeter according to claim 6, characterized in that: In step S5, the shape of the copper foil consists of two rectangles with different sizes, and the sizes are 11mm×3mm and 14mm×12mm respectively.

10. The method for preparing a paper-based gravimeter according to claim 6, characterized in that: In step S6, the diameter of the conductive silver paste is 1.5mm - 3mm, the drying temperature is 30 - 45°C, the drying time is 10 minutes, and the drying atmosphere is air.

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