Insect repellent devices and textile products

Abstract

To provide a device that has few limitations of a structure and the like without using any consumable supply and can drive out mosquitoes more strongly.SOLUTION: An insect proof apparatus 10 for driving out flying insects such as mosquitoes includes: a power source 11 for generating a rectangular wave or sawtooth wave; and an electrode group 13 in which linear electrodes 12 are arranged in parallel while being spaced apart in a width direction and every other electrode are connected to an opposite pole of the power source.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a device for repelling flying insects such as mosquitoes, and more particularly to a device for repelling flying insects by utilizing a rapid change in an electric field.

Background Art

[0002] Mosquitoes are known to transmit various infectious diseases such as dengue fever, Zika virus infection, and malaria. As methods for controlling or repelling mosquitoes, mosquito coils and insecticides have been used since ancient times. However, when used outdoors, there are drawbacks such that the effects are not constant or do not last due to the influence of wind direction and the like. In addition, insecticidal lamps that attract pests by ultraviolet light are not effective for mosquitoes that react to carbon dioxide emitted by humans depending on the type of mosquito. Therefore, a device that attracts and captures mosquitoes with an odor similar to human sweat has been put into practical use. However, using such a device requires the labor of regularly replenishing an attractant for generating the odor.

[0003] Patent Documents 1 to 5 describe an electrostatic field generator for charging and capturing or repelling pests, mold spores, and bacterial cells by an electrostatic field screen or barrier. In addition, Patent Document 6 describes a method for controlling pests by applying a transient voltage to a ferroelectric thin film and using non-compensated charges generated on its surface. Specifically, in a device provided with a substrate electrode covering the entire one surface of a ferroelectric thin film and a surface electrode partially covering the other surface, a large amount of charges are generated on the ferroelectric surface to which a voltage is applied from the substrate electrode side, and pests such as cockroaches are repelled by active species such as generated hydroxyl radicals (·OH).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

[0005] However, experimental results described later in this specification suggest that the effect of repelling mosquitoes using electrostatic fields as described in Patent Documents 1 to 5 is not significant. Furthermore, the method described in Patent Document 6 requires that the surface of the ferroelectric thin film be exposed over the entire area where the pests are to be repelled, which limits the structure and installation location of the device.

[0006] This invention has been made in consideration of the above, and aims to provide a device that does not use consumables, has fewer structural limitations, and can more powerfully repel flying insects such as mosquitoes. [Means for solving the problem]

[0007] To address the above problem, the present invention repels flying insects such as mosquitoes by applying a rapidly changing voltage between parallel electrodes, thereby rapidly changing the nearby electric field.

[0008] Specifically, the insect repellent device of the present invention is an insect repellent device for repelling flying insects, and comprises a power supply that generates a square wave or a sawtooth wave, and an electrode group in which linear electrodes are arranged in parallel at intervals, and each electrode is connected to the opposite pole of the power supply.

[0009] Here, the square wave or sawtooth wave may be either a continuous wave or a pulsed wave. Also, the opposite poles of the power source refer to the positive and negative poles in the case of DC, and the grounded and ungrounded sides in the case of AC.

[0010] In the insect repellent device described above, preferably, the electric field strength generated between adjacent electrodes by the peak voltage applied to the electrodes by the power supply is 43 V / mm or more.

[0011] In the insect repellent device described above, the electrode group may be sandwiched between dielectric sheets. Here, the sheets include a film.

[0012] Alternatively, in the insect repellent device described above, the electrodes may be arranged in a mesh consisting of vertical lines covered with a dielectric material and horizontal lines made of a dielectric material, spaced apart and parallel to the vertical lines.

[0013] The textile product of the present invention is a textile product into which any of the above insect-repellent devices is incorporated. [Effects of the Invention]

[0014] According to the insect repellent device of the present invention, applying a rectangular wave or sawtooth wave voltage between adjacent electrodes causes a rapid change in the electric field between them. Flying insects are repelled by this change in electric field, so flying insects can be repelled without using consumables. [Brief explanation of the drawing]

[0015] [Figure 1] This diagram shows the configuration of the insect control device according to the first embodiment. A: Plan view. B: Cross-sectional view of A. [Figure 2] A-F: Examples of voltage waveforms generated by a power supply. [Figure 3] This is a diagram showing the configuration of the insect control device according to the second embodiment. [Figure 4] This figure shows the relationship between the applied voltage and the rate of mosquito reduction obtained through experiments. [Modes for carrying out the invention]

[0016] Referring to FIG. 1, the insect-proof device 10 of the first embodiment includes a laminate 15 in which linear electrodes 12 are arranged in parallel at intervals in the width direction to form an electrode group 13, and the electrode group 13 is sandwiched between two dielectric sheets 14, and a power source 11.

[0017] Each electrode 12 is connected to an opposite electrode (11a or 11b) for each one of the two electrodes 11a and 11b provided in the power source 11. In other words, the electrodes 12 constituting the electrode group 13 are divided into electrodes 12a connected to one electrode 11a of the power source 11 and electrodes 12b connected to the other electrode 11b of the power source 11, and the electrodes 12a connected to one electrode 11a and the electrodes 12b connected to the other electrode 11b are arranged alternately.

[0018] The material of the electrode 12 is not particularly limited as long as it is a conductor, and for example, it is copper. Further, the electrode 12 being linear means that the electrode has a shape extending in one direction, and being linear includes being in a strip shape having a certain width.

[0019] The material of the dielectric sheet 14 is not particularly limited as long as it is a dielectric. A sheet means a planar one, and a rigid plate and a thin and flexible film are also included in the sheet. As the dielectric sheet 14, for example, a plate or film of synthetic resin, a glass plate, or a fabric made of chemical fiber or natural fiber can be used. By sandwiching the electrode group 13 between a synthetic resin plate or a glass plate, a rigid or flexible panel-shaped laminate 15 can be obtained. By sandwiching the electrode group 13 between a synthetic resin film or a fabric, a flexible film or cloth-shaped laminate 15 can be obtained. When laminating the electrode group and the dielectric sheet, an adhesive or the like may be used.

[0020] The dielectric sheet 14 can be omitted on one side or both sides if the distance between the electrodes can be maintained by other means. A mesh-type insect-proof device without a dielectric sheet will be described later as the second embodiment.

[0021] When the power supply 11 is activated and a voltage is applied between adjacent electrodes 12a and 12b, an electric field is generated between the electrodes. The electric field lines of this electric field are densest between electrodes 12a and 12b, but they also leak outside the dielectric sheet 14, and the rapid change in this electric field can repel, or drive away, flying insects. In the following, applying a voltage between adjacent electrodes may simply be referred to as "applying a voltage to the electrodes."

[0022] The power supply 11 generates a square wave or a sawtooth wave between two poles 11a and 11b. The voltage generated by the power supply 11 may be DC or AC. In this specification, DC voltage refers to a voltage whose direction does not change over time, and in the case of a DC square wave or sawtooth wave, the magnitude of the voltage changes periodically over time.

[0023] The power supply 11 preferably generates an alternating current voltage because it provides a greater repelling effect. For example, mosquitoes have sharp claws at the tips of their legs, which allow them to grip the surface where they land, enabling them to stay in place. The mosquito's exoskeleton and wings are made of chitin and become slightly charged by high-speed flapping, so the mosquito is pushed in the direction of the electric field. When a direct current voltage is applied to the electrodes, the mosquito is pushed in one direction, but when an alternating current voltage is applied, the direction of the electric field is reversed, causing the mosquito to shake and making it difficult for it to stay in place. This repelling effect also works on other flying insects that flap their wings at high speeds, similar to mosquitoes.

[0024] Figure 2 shows an example of a voltage waveform generated by the power supply 11. Figure 2A is an AC rectangular wave, which is a continuous wave. Figure 2B is a DC rectangular wave. The waveform in Figure 2B is the same as the waveform in Figure 2A, but offset by the peak voltage. When the low voltage portion is 0V, as in Figure 2B, the waveform can be considered a pulsed rectangular wave. The rectangular wave generated by the power supply 11 may be AC ​​or DC, but AC is preferred.

[0025] Figures 2C and 2D show AC sawtooth waves. In Figure 2C, the voltage gradually increases and then drops sharply. In Figure 2D, the voltage sharply increases and then gradually decreases. The waveform in Figure 2D is sometimes called an inverse sawtooth wave, but in this specification, the term sawtooth wave is used to refer to both the cases in Figures 2C and 2D. Like square waves, sawtooth waves can be AC ​​or DC, but AC is preferred.

[0026] Furthermore, the square wave or sawtooth wave generated by the power supply 11 may be a continuous wave with a continuously repeating waveform, or a pulsed wave with an intermittently repeating waveform. Figure 2E is an AC square wave with pulses, and Figure 2F is a DC square wave with pulses. Both Figure 2A and Figure 2E are AC square waves with pulses, but in Figure 2A the pulse width and pulse interval are equal, whereas in Figure 2E the pulse width is narrow, and after a rapid increase in voltage, the voltage drops sharply again for a very short duration.

[0027] If Vp is the peak voltage applied by the power supply 11 to the electrode 12, and d is the distance between adjacent electrodes 12a and 12b, then the maximum electric field strength generated between the electrodes is Vp / d. From experimental results described later, this maximum electric field strength Vp / d is preferably 43V / mm or higher, more preferably 143V / mm or higher, and even more preferably 229V / mm or higher. On the other hand, the peak voltage Vp is preferably 141V or lower, and more preferably 24V or lower. This is because if the peak voltage is too high, the manufacturing cost of the insect repellent device will increase due to the need for structures to prevent short circuits between electrodes.

[0028] The frequency of the voltage generated by power supply 11 is preferably 0.1 Hz or higher, more preferably 1 Hz or higher. This is because changing the electric field at a certain frequency allows the insect-repellent effect to be sustained. On the other hand, the frequency of the voltage generated by power supply 11 is preferably 200 Hz or lower, more preferably 60 Hz or lower. This is because lower frequencies result in lower circuit manufacturing costs, and since the main AC frequencies in Japan are 60 Hz or 50 Hz, lowering the frequency to 60 Hz or lower further reduces circuit manufacturing costs.

[0029] The rise time or fall time of the square wave or sawtooth wave generated by the power supply 11 is preferably 10 ms or less, more preferably 1 ms or less. This is to make the change in the electric field steep. On the other hand, the lower limits of the rise time and fall time are not particularly limited and are usually determined by the characteristics of the device, such as the slew rate of the amplifier.

[0030] The capacity of the power supply 11 can be determined according to the size of the insect repellent device. In the insect repellent device 10 of this embodiment, no current flows between the electrodes 12, so the capacity of the power supply 11 can be small.

[0031] When using the insect repellent device 10 of this embodiment, the laminate 15 is placed in the location where flying insects are to be repelled, and the power supply 11 is activated to apply voltage to the electrodes 12. The electric field lines of the electric field generated between adjacent electrodes 12a and 12b are densest between electrodes 12a and 12b, but they also leak outside the dielectric sheet 14, and this rapid change in electric field can repel, or drive away, flying insects such as mosquitoes.

[0032] As an example of the application of the insect repellent device of this embodiment, the insect repellent device 10 can be incorporated into an air purifier with a mosquito-catching function. In an air purifier with a mosquito-catching function, mosquitoes that approach the intake port are sucked in, captured, and exterminated by the suction power of the air purifier. However, mosquitoes that were not sucked in by clinging to the surface of the housing around the intake port sometimes flew away again when the power of the air purifier was turned off. By incorporating the insect repellent device of this embodiment into the housing around the intake port, mosquitoes that try to cling to the area around the intake port can be detached from the surface of the housing and easily sucked in.

[0033] Other examples of applications include the use of a panel-shaped laminate 15, in which a transparent synthetic resin plate or glass plate is used as the dielectric sheet 14, in the windows of buildings. Alternatively, laminated glass, in which a film-shaped laminate using a transparent synthetic resin film as the dielectric sheet 14 is sandwiched between two glass plates, can be used in the windows of buildings.

[0034] Another example of its application is that the insect repellent device 10 can be incorporated into clothing. By sewing a fabric-like laminate 15 using cloth as the dielectric sheet 14, or by sewing or attaching it to the surface of clothing, insect repellent functionality can be added to work clothes worn outdoors or various types of clothing worn during outdoor activities such as camping. As mentioned above, the power supply for the insect repellent device does not need to be large, so it is also possible to incorporate a small power supply, such as a high-voltage pulse power supply, into the clothing.

[0035] Referring to Figure 3, the insect control device of the second embodiment has a 20, a mesh 21, and a power supply 11. The mesh 21 is composed of a group of electrodes 13, in which vertical lines 22, each covered with a dielectric material and spaced apart, are arranged in parallel in the width direction, and horizontal lines 23 made of dielectric material that are spaced apart and parallel to the vertical lines. The electrodes 12 and the power supply 11 are the same as in the first embodiment.

[0036] It is preferable that the vertical lines 22 and horizontal lines 23 be bonded together at each intersection. The reason for coating the electrodes 12 with a dielectric is to prevent any conductor from contacting them and causing a short circuit between the electrodes.

[0037] When using the insect repellent device 20 of this embodiment, the mesh 21 is placed in the area where flying insects are to be repelled, and the power supply 11 is activated to apply voltage to the electrodes 12. The insect repellent device 20 can be used for various purposes by taking advantage of its breathability.

[0038] As an example of the application of this insect-repellent device, by supporting both ends of the vertical wires 22 and horizontal wires 23 with a frame (not shown) and applying tension to the vertical and horizontal wires, it can be used for screen doors in houses and the like. To prevent mosquitoes from entering with a screen door, it is necessary to use a screen with a small mesh opening by narrowing the spacing between the wires. As a result, the pressure loss of the air passing through the screen increases, and the ventilation of the screen door becomes poor. With this insect-repellent device, it is possible to create a screen with good ventilation while preventing mosquito entry by widening the mesh opening. According to model calculations, when the diameter of the wires is 1 mm, widening the mesh opening from 1.5 mm × 1.5 mm to 5 mm × 5 mm can reduce the pressure loss for an airflow of 1 m / s from 27 Pa to 0.6 Pa.

[0039] Other examples of its use include mosquito nets, insect nets for strollers, and drying baskets for food and dishes. Furthermore, other examples of its use include various types of clothing such as mesh parkas with insect-repellent properties for outdoor activities, and insect nets that attach to hats to cover the head. [Examples]

[0040] The experiment was conducted using the insect repellent device shown in Figure 1. Five strips of copper foil, 10 mm wide, 280 mm long, and 0.3 mm thick, were used as electrodes. These were arranged in parallel with a 35 mm gap in the width direction, and sandwiched between two acrylic plates measuring 300 mm x 225 mm and 2 mm thick. Black paper, which attracts mosquitoes, was attached to the surface of one of the acrylic plates to create a laminate. A function generator and amplifier were connected to power the device. The function generator generated voltage signals of various waveforms and frequencies, which were then amplified by the amplifier. Each electrode was connected to the opposite pole of the amplifier output.

[0041] A transparent box measuring 350 x 350 x 350 mm was placed inside a stack of materials with black paper facing upwards, and approximately 100 female Aedes albopictus mosquitoes were trapped inside. After waiting about 5 minutes for many of the mosquitoes to settle on the stack, the power was turned on, and the mosquitoes' movements were recorded on video.

[0042] Table 1 shows the experimental conditions and results.

[0043] [Table 1]

[0044] In Table 1, in Examples 1-9 and Example 11, a continuous rectangular AC wave as shown in Figure 2A was applied to the electrodes. In Example 10, a rectangular pulsed AC wave as shown in Figure 2E was applied to the electrodes. The pulse rise time was approximately 14 μs, and the pulse width was approximately 2 ms. Example 12 was obtained by offsetting the rectangular wave from Example 11 by the peak voltage (3 kV) to obtain a rectangular DC pulsed wave as shown in Figure 2B. Example 13 was obtained by offsetting the rectangular wave from Example 11 by -3 kV in the opposite direction to Example 12. In Comparative Example 1, a constant DC voltage was applied to the electrodes. In Comparative Example 2, an AC sine wave was applied to the electrodes. In Table 1, "voltage amplitude" is the peak-to-peak voltage, and "maximum electric field strength" is the value obtained by dividing the peak voltage Vp by the electrode spacing of 35 mm.

[0045] In Table 1, the "Before Operation" and "After Operation" counts of mosquitoes refer to the number of mosquitoes resting on the black paper before and after power activation, respectively. The "Reduction Rate" is the percentage decrease from the number of mosquitoes before power activation to the number of mosquitoes after activation. A higher reduction rate indicates a greater mosquito repellent effect. Figure 4 shows the relationship between peak voltage Vp and the mosquito reduction rate.

[0046] Referring to Table 1 and Figure 4, when comparing the waveform of the applied voltage, Examples 1-4 (square wave) with a continuous AC wave and a peak voltage of 5kV and Comparative Example 2 (sine wave), the square wave showed a greater reduction rate than the sine wave, and the difference in the reduction rates between the two was extremely large. From this, it was found that abrupt changes in the electric field due to a steep change in voltage are effective in repelling mosquitoes.

[0047] Regarding the difference in effectiveness between DC and AC, when comparing Comparative Example 1, in which a constant DC voltage (10kV) was applied, with Examples 4 and 5, in which a square wave AC with the same peak voltage of 10kV was applied, Examples 4 and 5 showed a greater reduction in mosquitoes. In Comparative Example 1, many mosquitoes on the paper flew away when the power was turned on, which is thought to be due to the change in the electric field at the moment the voltage was applied. Furthermore, since the effect of repelling mosquitoes is greatest at the moment the voltage is applied, it is thought that continuously applying a constant DC voltage does not have a significant effect in repelling mosquitoes.

[0048] Furthermore, the results from Examples 11-13 clearly showed that applying AC voltage yielded a greater effect than applying DC voltage. Examples 11-13 all used a square wave with a voltage amplitude of 6kV. The peak voltage was ±3kV for Example 11 (AC), and +6kV and -6kV for Examples 12 and 13 (DC), respectively. In other words, although the DC experiment had a larger peak voltage and a greater maximum electric field strength, the mosquito reduction rate was greater in Example 11 (AC). From this, it was confirmed that AC is more effective at repelling mosquitoes than DC. The reason for this is thought to be that, as mentioned above, the reversal of the direction of the electric field shakes the mosquito, making it difficult for it to stay in place.

[0049] In experiments using AC voltage, a comparison of Examples 1-9, which used a rectangular continuous wave, showed that the higher the peak voltage and the higher the maximum electric field strength, the greater the mosquito reduction rate. From Figure 4, it can be seen that a peak voltage of approximately 8kV (maximum electric field strength of approximately 229V / mm) or higher can be used to achieve a mosquito reduction rate of nearly 100%. From these results, it was found that the electric field strength generated at the peak voltage should preferably be 43V / mm or higher, more preferably 143V / mm or higher, and even more preferably 229V / mm or higher.

[0050] Regarding the effect of frequency, when comparing the results of Examples 1-4, 5-6, and 7-9, where all other conditions were the same but only the frequency differed, the effect of frequency was not clear.

[0051] Regarding the effect of the square wave pulse width, in Example 10, where pulses with short voltage durations were applied, the mosquito reduction rate was greater than in Examples 1-4, which also used AC with a peak voltage of 5kV. However, the difference was slight, and it was not possible to definitively determine the effect of pulse width based solely on this experimental result.

[0052] Furthermore, the same experiment was conducted with German cockroaches using the same device as described above, but no change in the cockroaches' behavior was observed even when the power was turned on, and no effect in repelling cockroaches was observed.

[0053] The present invention is not limited to the embodiments or examples described above, and various modifications are possible within the scope of its technical concept. [Industrial applicability]

[0054] The insect repellent device of the present invention can be used to repel various types of mosquitoes, as well as small flying insects such as gall midges, leafminers, drain flies, phorid flies, and fruit flies. [Explanation of symbols]

[0055] 10 Insect control device 11 Power supply 11a, 11b Power supply poles 12, 12a, 12b electrode 13 electrode group 14 Dielectric Sheet 15 Laminate 20 Insect control device 21 mesh 22 vertical lines 23 horizontal lines

Claims

1. A power supply that generates a square wave or sawtooth wave, The device has linear electrodes arranged in parallel at intervals, and each of these electrodes is connected to the opposite pole of the power supply. The electrode group is sandwiched between dielectric sheets. Insect control device.

2. A power supply that generates a square wave or a sawtooth wave, The device has linear electrodes arranged in parallel at intervals, and each of these electrodes is connected to the opposite pole of the power supply. A dielectric sheet is laminated on one side of the electrode group. Insect control device.

3. A power supply that generates a square wave or sawtooth wave, The device has linear electrodes arranged in parallel at intervals, and each of these electrodes is connected to the opposite pole of the power supply. The electrodes are arranged in a mesh consisting of vertical lines covered with a dielectric material and horizontal lines made of the dielectric material, spaced apart and parallel to the vertical lines. Insect control device.

4. The electric field strength generated between adjacent electrodes by the peak voltage applied to the electrodes by the power supply is 43 V / mm or more. The insect control device according to any one of claims 1 to 3.

5. A textile product incorporating the insect-repellent device described in any one of claims 1 to 4.

Images