JP2011173316A - Control method of direction of flight object, and control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To apply a control method to a minute flight object composed of all kinds of materials, to easily process a nozzle, and to simplify and miniaturize an apparatus. <P>SOLUTION: In the control method of the direction of the flight object which is injected in the atmosphere or a vacuum and flies, the flight object is a liquid droplet, an uneven electric field is generated in the peripheral space of the flight course by applying a voltage to a control electrode arranged near the flight course of the liquid droplet, and the flight direction of the liquid droplet is controlled without contact by a dielectric force applied to the liquid droplet by the electric field. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a control method and control device for a flight direction of a flying object.

  Conventionally, techniques for controlling the flying direction of fine particles flying in space have been used in various fields. Here, in particular, the inkjet technology will be described with reference to a technology for controlling the flight direction of droplets ejected from a nozzle (see, for example, Non-Patent Document 1).

  Inkjet technology can be broadly divided into an on-demand inkjet method in which droplets are ejected at an arbitrary time by an instantaneous pressure increase, and minute droplets by splitting a columnar liquid column continuously ejected from a nozzle. There is a continuous ink-jet method that generates

  In the continuous ink jet method, droplets are ejected using the force of a pump. For this reason, as compared with the on-demand ink jet method, a large number of droplets can be generated, and a highly viscous liquid can be ejected. Currently, inkjet is expected not only as a printer that prints on paper media, but also in various fields such as semiconductor processes. Considering such an application, the continuous ink jet method capable of ejecting a highly viscous organic solvent or the like at high speed is very effective.

  Although this is a highly useful continuous ink jet method, droplets are always ejected during operation. Therefore, it is necessary to select the droplets to be used and the droplets not to be used. As a method of selecting droplets, a method of performing charge deflection control is currently mainstream.

  In this method, the charging electrode is disposed at a position corresponding to the tip of the liquid column ejected from the nozzle, and the deflection electrode is disposed at a corresponding position in the traveling direction of the liquid droplet separated from the liquid column. To do. That is, the droplet separated from the tip of the liquid column is charged by the charging electrode, and then the charged droplet is deflected by the electrostatic field created by the deflection electrode. At this time, the charge amount of each droplet can be changed by changing the voltage of the charging electrode at a high speed. Therefore, the magnitude of the force received from the electrostatic field is different for each droplet, which makes it possible to select the droplets.

Series “Digital Printer Technology” Inkjet, 1st edition, edited by The Imaging Society of Japan, Tokyo Denki University Press, published on September 10, 2008, 2-7, 78-87 Paul R. Chiarot and T.B. Jones, “Dielectrophoretic deflection of ink jets”, Journal of Micromechanics and Microengineering, 19 (2009) 125018 (8pp).

  However, in the conventional method, since the charged droplet is deflected, the liquid needs to have good conductivity in order to give the droplet a sufficient charge for deflection control. Therefore, it is impossible to use an organic solvent having poor conductivity, which hinders the use of the ink jet technology in the above-mentioned applied fields.

  However, as a method of controlling the ejection direction of droplets that do not have electrical conductivity, a temperature gradient is created near the nozzle by a heater, etc., and temperature dependence such as droplet viscosity and surface tension is used. There are a method for controlling the ejection direction, a method for controlling the ejection direction according to the flow of the atmosphere after ejection of the droplets, and the like. However, these methods have limitations on the types of droplets that can be applied. In addition, a finely processed nozzle is required, and the apparatus becomes large.

  Furthermore, a method using a dielectric force acting on a droplet has also been proposed (see, for example, Non-Patent Document 2). However, in this method, since all the droplets need to collide with the substrate and bounce off, the directionality of the droplets depends on the type of the droplet and the substrate material, Depending on the type, there is a possibility that the droplet does not rebound. In addition, the droplets may contaminate the substrate. Further, it has not been successful to individually control the direction of continuously ejected droplets.

  The present invention solves the above-mentioned conventional problems and can be applied to a minute flying object made of any kind of material, the nozzle can be easily processed, and the flying can simplify and downsize the apparatus. It is an object of the present invention to provide a control method and control device for the flight direction of an object.

  Therefore, in the method for controlling the flying direction of the flying object of the present invention, the flying object is controlled in the direction of flight of the flying object that is injected into the atmosphere or vacuum, and the flying object is a droplet, By applying a voltage to a control electrode disposed in the vicinity of the droplet flight path, a non-uniform electric field is generated in the peripheral space of the flight path, and the liquid force is applied by the dielectric force acting on the droplet by the electric field. Non-contact control of droplet flight direction.

  In another method of controlling the flying direction of a flying object of the present invention, the flying direction of the droplet is controlled while the droplet is flying in the atmosphere or in a vacuum.

  In yet another method for controlling the flying direction of a flying object according to the present invention, the droplet is formed by splitting a continuous liquid column ejected from a nozzle.

  In yet another method for controlling the flying direction of a flying object of the present invention, the diameter of the range covered by the dielectric force is smaller than the interval between adjacent droplets.

  In yet another method for controlling the flying direction of a flying object of the present invention, the droplets are not charged.

  In yet another method for controlling the flying direction of a flying object according to the present invention, a voltage is applied to the control electrode at a timing when a desired droplet passes in the vicinity of the control electrode, thereby flying continuously. The flight direction of a plurality of droplets is selectively controlled.

  In still another flying object control method of the present invention, the droplet has a diameter of 0.5 mm or less.

  The flying object control apparatus for a flying object according to the present invention is a control apparatus for the flying direction of a flying object that is injected into the atmosphere or vacuum, and the flying object is a droplet, and the flying of the droplet A control electrode disposed in the vicinity of the path, and a voltage applying device that applies a voltage to the control electrode, and the voltage applying device applies a voltage to the control electrode, so that the space around the flight path A non-uniform electric field is generated, and the flying direction of the droplet is controlled in a non-contact manner by a dielectric force acting on the droplet by the electric field.

  In another flying object flight direction control device of the present invention, the control electrode further has a bar-like or needle-like shape with a pointed tip, and the tip has a diameter adjacent to the liquid. It is arranged so as to be smaller than the interval between the droplets and to be located in the vicinity of the flight path.

  In still another flying object flight direction control device according to the present invention, the control electrode further has a plate-like shape with a sharp tip, and the tip has a thickness greater than an interval between adjacent droplets. It is small and disposed so as to be located in the vicinity of the flight path.

  According to the present invention, the flying direction of a minute flying object made of any kind of material can be controlled without contact.

It is a figure which shows the structure of the flight direction control apparatus in embodiment of this invention. It is a photograph which shows the mode of the droplet deform | transformed by the Maxwell stress in embodiment of this invention. It is a photograph which shows the mode of the droplet by which the flight direction was deflect | deviated by the Maxwell stress in embodiment of this invention. It is a photograph which shows the mode of the droplet by which the flight direction was deflected every other drop by the Maxwell stress in embodiment of this invention. It is a figure which shows the relationship between the voltage applied to the deflection | deviation electrode in embodiment of this invention, and the deflection angle of a droplet. It is a photograph which shows the mode of the droplet by which the flight direction was deflect | deviated by the Maxwell stress at the time of using the plate-shaped deflection | deviation electrode in embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a configuration of a flight direction control apparatus according to an embodiment of the present invention.

  In the figure, reference numeral 10 denotes a flight direction control device in the present embodiment, which is a device that controls the flight direction after injection with respect to fine particles injected at an initial velocity in the atmosphere or vacuum, and more Specifically, it is an apparatus that controls the flight direction of the droplets 21a as fine particles. In the example shown in the figure, the flight direction control device 10 generates a droplet 21a that is a flying object and causes the droplet to fly, and a liquid that collects and regenerates at least some of the droplets 21a. It also includes a drop collection device.

  Reference numeral 11 denotes a head portion as a droplet generation unit which is a part of the droplet generation device, and includes a storage space 11b for storing the liquid 21 therein, and is a minute droplet of the liquid 21. The droplet 21a is ejected into the atmosphere or vacuum, which is the space outside the head unit 11. The head portion 11 includes a nozzle 11a as a minute opening formed at the tip (left end in the figure), and the inside of the accommodation space 11b communicates with the outer space through the nozzle 11a. The liquid 21 is supplied into the storage space 11b in a state of being pressurized from the pressurizing pump 19 connected to the storage space 11b via the conduit 14.

  Furthermore, the head unit 11 includes a vibration applying unit 12 that applies vibration to the liquid 21 in the accommodation space 11b. In the example shown in the figure, the vibration applying unit 12 includes, for example, a piezoelectric element such as a piezo element, and is disposed on the opposing wall of the head unit 11 to vibrate the liquid 21 in the accommodation space 11b. Apply pressure oscillation. Reference numeral 13 denotes a vibration applying unit driving device for driving the vibration applying unit 12. The drive signal is a voltage that fluctuates in a predetermined cycle such as a sine wave of several tens to several hundreds [kHz]. An excitation voltage circuit for generating a signal is provided, and the drive signal is applied to the vibration applying unit 12 to vibrate the vibration applying unit 12.

  The head unit 11 operates on the same principle as that of the apparatus for generating ink droplets used in the continuous ink jet method described in the section “Background Art”. When the pressurized liquid 21 in the storage space 11b is discharged from the nozzle 11a to the outer space, it is ejected as a continuous liquid column 21b. At this time, continuous vibration is applied to the head unit 11 at a predetermined period by the vibration applying unit 12, and the liquid column 21 b is regularly squeezed by this vibration, and the liquid column 21 b is caused by the surface tension of the liquid 21. Continuously split into droplets 21a and fly. The flying speed of the droplet 21a is, for example, about 1 to 10 [m / s].

  The liquid 21 may be made of any kind of material. For example, the liquid 21 may have conductivity or may not have conductivity. Specifically, it may be water, oil or the like, may be an ink used in a general ink jet printer, may be a gel-like ink, an aqueous solution, an organic solvent, or silicone. Oil etc. may be sufficient.

  The viscosity of the liquid 21 is, for example, in the range of 1 to 3 [mPa · s], preferably in the range of 0.5 to 100 [mPa · s], and more preferably in the range of 0.5 to 1000. The range is [mPa · s]. Further, the surface tension of the liquid 21 is, for example, in the range of 20 to 70 [mN / m], and desirably in the range of 10 to 100 [mN / m]. Further, the diameter of the droplet 21a is preferably a small value of 0.5 [mm], that is, 500 [μm] or less, for example, in the range of 8 to 100 [μm], preferably 5 to 5 [μm]. It is in the range of 300 [μm], more preferably in the range of 1 to 300 [μm].

  Reference numeral 15 denotes a deflection electrode as a control electrode for controlling the flight direction of the droplet 21a. The deflection electrode 15 is disposed in the vicinity of the flight path of the droplet 21a, and is applied to the flight path of the droplet 21a by applying a voltage. An uneven electric field is generated in the surrounding space. The flying direction of the droplet 21a is controlled in a non-contact manner by the dielectric force acting on the droplet 21a by the electric field. In the example shown in the figure, the deflection electrode 15 is a minute member having a rod-like or needle-like shape with a sharp tip (upper end in the figure), or an elongated plate shape with a sharp tip (knife edge shape). And the tip is disposed so as to be located in the vicinity of the flight path of the droplet 21a. In the figure, the flight path of the droplet 21a is a straight line from the nozzle 11a to the left, and the droplet 21a whose flight direction is not controlled by the deflection electrode 15 is linearly moved to the left along the flight path. It flies toward the target and collides with a target member as a target disposed at the end (not shown) of the flight path.

  Reference numeral 16 denotes a voltage application device for applying a voltage to the deflection electrode 15, which varies as a control signal for controlling the flight direction of the droplet 21 a, for example, at a predetermined cycle of several to several thousand [kHz]. A deflection voltage circuit for generating a positive or negative voltage signal of about several hundred to several thousand [V] is provided. The voltage signal is applied to the deflection electrode 15 and a voltage is applied to the deflection electrode 15 at a desired timing. Note that in order to selectively control the flight direction of the droplet 21a, it is necessary to adjust the timing at which the voltage is applied to the deflection electrode 15 and the timing at which the droplet 21a is generated. And the vibration provision part drive device 13 is mutually connected.

  Further, 17 is a gutter as a droplet recovery member which is a part of the droplet recovery device, and the flight direction is controlled by at least a part of the flying droplet 21a, specifically, the deflection electrode 15 to control the flight direction. The droplets 21a that fly downward from the flight path are collected. A collection tank 18 is connected to the gutter 17 via a conduit 14, and the droplet 21 a collected by the gutter 17 is stored as a liquid 21 in the collection tank 18. The recovery tank 18 is desirably provided with a filtering device for removing foreign substances, impurities, and the like from the recovered liquid 21, and an adjusting device for adjusting physical properties such as viscosity. Then, the liquid 21 stored in the recovery tank 18 is supplied again into the accommodation space 11b by the pressurizing pump 19.

  In the example shown in the figure, the deflection electrode 15 is disposed below the flight path so as to deflect the flight direction of the droplet 21a downward. However, the deflection electrode 15 is disposed above the flight path. May be arranged so as to deflect the flight direction of the droplet 21a upward, or the deflection electrode 15 may be arranged on any side of the flight path so as to deflect the flight direction of the droplet 21a in any direction. It may be.

  In the example shown in the figure, the droplet 21a whose flight direction is deflected by the deflection electrode 15 is collected by the gutter 17, and the droplet 21a whose flight direction is not deflected by the deflection electrode 15 is in the flight path. The liquid droplet 21a whose flight direction is deflected by the deflection electrode 15 collides with the target member, and the flight direction is not deflected by the deflection electrode 15. The droplet 21a may be collected by the gutter 17.

  Furthermore, in the example shown in the figure, the flying direction of the droplet 21a deflected by the deflection electrode 15 is only one, but the degree of deflection of the droplet 21a is adjusted by adjusting the voltage applied to the deflection electrode 15. The liquid droplet 21a may be deflected in two or more directions, that is, in a plurality of directions.

  The flight direction control device 10 in the present embodiment can be applied to, for example, an ink jet printer that performs printing on paper media, product resin packages, ceramics, clothing, etc. It can also be applied to drawing formation of electrode patterns, conductive circuit patterns, semiconductor circuit patterns, insulating layer patterns, etching patterns, etc., and can also be applied to three-dimensional modeling in the molding of resin products, etc. It can also be applied to waveguide formation, optical semiconductor formation, lens manufacturing, etc., and can also be applied to the manufacture of DNA chips, biochips, etc. in biomedical etc., and catalyst in the manufacturing process of fuel cells, solar cells, etc. It can also be applied to coating, pattern formation, etc. and fly The present invention can be applied to any kind of use or field as long as the technique for selectively colliding the droplet 21a with a desired position of a desired target member by controlling the flight direction of the drop 21a can be applied. However, the application or field of application is not limited.

  Next, the operation of the flight direction control device 10 having the above configuration will be described.

  In the present embodiment, a minute deflection electrode 15 is disposed in the vicinity of the flight path of the droplet 21a as a minute flying object, and a voltage is applied to the deflection electrode 15 so as not to be near the flight path. A uniform electric field distribution is generated, whereby a force is applied to the droplet 21a by a dielectric force (Maxwell stress) acting on the droplet 21a, which is a dielectric, to control the flight direction of the droplet 21a. Do.

  There is a very steep electric field gradient at the sharp tip of the deflection electrode 15 in the form of a bar, needle or taper with a voltage applied. Thus, when there is a steep electric field gradient, a force called Maxwell stress works strongly. By using the Maxwell stress, even the droplet 21a made of a highly insulating material can be controlled without being charged. That is, even the droplet 21a made of a material such as an organic solvent or silicone oil that does not have conductivity is a dielectric, and therefore, Maxwell stress, which is a dielectric force, can be controlled.

  As shown in the figure, a rod-like or needle-like deflecting electrode 15 is arranged so that a sharp tip is positioned in the vicinity of the flight path of the droplet 21a ejected from the nozzle 11a of the head portion 11, A positive or negative voltage of about several hundred [V] to several [kV] is applied to the deflection electrode 15 when the droplet 21a to be deflected, that is, the droplet 21a to be deflected approaches the tip of the deflection electrode 15. At this time, the droplet 21 a existing in the vicinity of the tip of the deflection electrode 15 receives a force toward the tip of the deflection electrode 15, that is, an attractive force toward the tip of the deflection electrode 15, regardless of the positive or negative voltage due to Maxwell stress. .

  Here, when the time after the voltage is applied to the deflection electrode 15 is τ and the direction from the droplet 21a to the tip of the deflection electrode 15 is the x direction, the droplet 21a exists on the central axis of the deflection electrode 15. The magnitude of the force F when doing this is the level represented by the following equation (1) (see, for example, Non-Patent Document 3).

Ε ₀ : dielectric constant of air, R: radius of droplet 21 a, σ: conductivity of liquid 21, σ ₀ : conductivity of air, ε: dielectric constant of liquid 21, E: electric field created by deflection electrode 15 , Τ _MW : relaxation time constant (ε + 2ε ₀ ) / (σ + 2σ ₀ ) until free electrons are accumulated on the surface of the droplet 21a.

Thomas B. Jones, “Electromechanics of Particles”, Cambridge University Press 1995.

When the liquid 21 has a sufficiently high conductivity and τ _MW is sufficiently smaller than several to several tens [μs], which is a time scale for the droplet 21 a to pass through the tip of the deflection electrode 15, the term depending on the dielectric constant is quickly relaxed. Therefore, the magnitude of the force F is expressed by the following equation (2).

On the other hand, if the insulation of the liquid 21 is high and τ _MW is sufficiently large, the term depending on the dielectric constant is not relaxed while controlling the droplet 21a, so the magnitude of the force F is given by It is represented by (3).

The coefficient (ε−ε ₀ ) / (ε + 2ε ₀ ) in the equation (3) is called a Clausius-Mosotti factor.

  The equations (1) to (3) are first-order approximations and are appropriate when the distance between the droplet 21a and the deflection electrode 15 is sufficiently wide with respect to the size of the droplet 21a. Note that the n-th order approximate term in the formula (3) is as shown in the following formula (4) (for example, see Non-Patent Document 3).

As shown in the formula (1), the force acting on the droplet 21a has the following three features.
-The magnitude of the force depends on two physical properties, conductivity and dielectric constant.
Deflection control can be performed without depending on the size of the droplet 21a.
-Proportional to the slope of the square of the electric field created by the deflection electrode 15.

The relative permittivity ε ′ of the liquid 21 is about 2 to 100. The corresponding Clausius-Mosotti factor values are 0.25 to 0.97. Further, even if the liquid 21 has high conductivity and the magnitude of the force F is expressed by the above formula (2), the factor of (σ−σ ₀ ) / (σ + 2σ ₀ ) is the maximum, It is 1 at most. After all, even if the type of the liquid 21 is changed, the magnitude of the force F does not change by an order of magnitude.

  Therefore, the control method for controlling the flight direction of the droplet 21a using the Maxwell stress, like the flight direction control device 10 in the present embodiment, does not depend on the physical properties of the liquid 21 or the droplet 21a. Note that the same argument holds even if the deflection electrode 15 has a tapered and elongated plate shape. The period of the voltage signal corresponds to the generation period of the droplets 21a ejected from the nozzle 11a.

  On the other hand, in the method of performing charge deflection control described in the section “Background Art”, as described in the section “Problems to be Solved by the Invention”, the droplet 21a of the liquid 21 having a low conductivity is also described. The flight direction cannot be controlled. This is because the characteristic time scale τ of charge transfer inside the liquid 21 is expressed as in the following equation (5) (see, for example, Non-Patent Document 4).

Kazutoshi Asano, Journal of the Electrostatic Society, 18 (1994) 18.

  If the relative permittivity ε ′ of the liquid 21 is 2 and the electrical resistivity γ is 1 [TΩ · m], that is, if the liquid 21 is an insulating liquid, the time scale τ is 20 Second. Further, the same amount of time is required to control the charge amount of one droplet 21a. Accordingly, when the generation cycle of the droplets 21a ejected from the nozzle 11a is a high-speed cycle of about several to several thousand [kHz], the droplet 21a made of an insulating liquid is used in the charge deflection control method. It is impossible to control the flight direction.

  Maxwell stress is a body force. As shown in the equation (1), the magnitude of the force F is proportional to the cube of the radius of the droplet 21a. For this reason, the force F is a volume force proportional to the volume of the droplet 21a. On the other hand, the inertia force is also a body force. For this reason, the deflection angle due to the Maxwell stress does not depend on the size of the droplet 21a.

  Further, the force F is a force proportional to the gradient of the square of the electric field. Therefore, in a space where the electric field gradient is very large, such as a pointed tip of a rod-like, needle-like, or tapered elongated plate-like deflection electrode 15, the force F is near. Works like distance power. The electric field in the vicinity of the sharp tip of the deflection electrode 15 can be approximated by an electric field formed by a charged sphere. The radius of the charged sphere used in the approximation is the radius of curvature of the tip of the deflection electrode 15.

The electric field E created by the charged sphere is expressed as E = A / r ² . Here, A is a coefficient depending on the radius of curvature of the needle and the voltage, and r is a distance from the charged sphere.

  Then, the equation (3) becomes the following equation (6).

  As shown in the equation (6), the force F is a force that rapidly decreases as the distance from the tip of the deflection electrode 15 increases, and is proportional to the −5th power of the distance r. For this reason, it may be considered that the droplet 21 a passing near the tip of the deflection electrode 15 receives force only from the tip of the deflection electrode 15.

  Further, it is empirically that the interval between the droplets 21a continuously ejected from the nozzle 11a can be set to a range represented by the following formula (7) by adjusting the ejection pressure or the like. It is known (for example, refer nonpatent literature 5).

J. M. Schneider and C. D. Hendlick: Rev. Sci. Instrum. 35 (1964) 1349.

  From the above equation (8), the interval 1 between the droplets 21a can be expanded to 7 times the radius R of the droplets 21a.

As shown in the equation (6), the force F is proportional to the −5th power of the distance r between the tip of the deflection electrode 15 and the droplet 21a, which is a point charge. When the deflection electrode 15 is disposed so that the distance between the tip of the deflection electrode 15 and the droplet 21a when it is closest to the tip of the liquid crystal is about r = 2a, it exists closest to the tip of the deflection electrode 15. The force applied to the droplet 21a existing before and after the droplet 21a is about 10 ⁻³ relative to the force applied to the droplet 21a.

  Accordingly, it can be considered that the force F acts only on the droplet 21 a existing closest to the tip of the deflection electrode 15. That is, the diameter in the range covered by the dielectric force (Maxwell stress) acting on the droplet 21a by the electric field generated by applying a voltage to the deflection electrode 15 is smaller than the interval between the adjacent droplets 21a. Further, the diameter or thickness of the tip of the deflection electrode 15 is also smaller than the interval between the adjacent droplets 21a. Therefore, the flight direction control device 10 in the present embodiment can control the movement of each droplet 21a.

  Next, experimental results conducted by the inventor of the present invention will be described.

  FIG. 2 is a photograph showing the state of a liquid droplet deformed by Maxwell stress in the embodiment of the present invention, and FIG. 3 shows the state of a liquid droplet whose flight direction is deflected by Maxwell stress in the embodiment of the present invention. FIG. 4 is a photograph showing a state of a droplet whose flight direction is deflected every other drop by Maxwell stress in the embodiment of the present invention, and FIG. 5 is applied to the deflecting electrode in the embodiment of the present invention. FIG. 6 is a diagram showing the relationship between the voltage and the deflection angle of the droplet, and FIG. 6 shows the state of the droplet whose flight direction is deflected by the Maxwell stress when the plate-like deflection electrode in the embodiment of the present invention is used. It is a photograph shown.

  The inventor of the present invention creates a head portion 11 of the flight direction control device 10 using a glass capillary tube with a narrowed tip, and attaches a vibration applying portion 12 made of a piezoelectric element to the outside of the head portion 11. The experiment was conducted. In this experiment, pure water was used as the liquid 21.

  When the vibration applying unit 12 is operated by applying a drive signal from the vibration applying unit driving device 13, a pressure wave is applied from the outside to the head unit 11 filled with the liquid 21. The pressure wave propagates along the wall of the head portion 11, which is a capillary that narrows toward the tip portion, and is superimposed on the constant pressure applied by the pressure pump 19, and as a result, from the tip of the head portion 11. A liquid column 21b whose diameter changes periodically is injected. The liquid column 21b splits with the growth of periodic diameter fluctuations to generate droplets 21a. Thereby, as shown in FIGS. 2 to 4, a droplet 21 a was ejected.

  2 to 4, a member with a sharp tip protruding downward from the upper edge is a rod-like or needle-like deflection electrode 15 used in the experiment. The diameter of the tip of the rod-like or needle-like deflection electrode 15 is 100 [μm] or less, preferably 50 [μm] or less, which is smaller than the interval between adjacent droplets 21a.

  In the flying direction control device 10 shown in FIG. 1, the tip of the head unit 11 is drawn so as to face to the left. However, in the flying direction control device 10 used in the experiment, the tip of the head unit 11 is on the right. Note that it is suitable. In FIG. 4, a member having a sharp tip protruding from the left edge toward the right is the head portion 11 used in the experiment.

  Further, in the flight direction control device 10 shown in FIG. 1, the deflection electrode 15 is arranged below the flight path of the droplet 21a and its tip is drawn upward, but it was used in the experiment. It should be noted that in the flight direction control device 10, the deflection electrode 15 is disposed on the upper side of the flight path of the droplet 21a and the tip thereof is directed downward.

  In FIG. 2, the droplet 21 a is continuously ejected from the tip of the head unit 11, and a pulse voltage of 2 [kV] is applied to the deflection electrode 15 over 20 [μs]. In addition, a state in which the droplet 21a having a diameter of 30 [μm] closest to the tip of the deflection electrode 15 is deformed by Maxwell stress is shown. FIG. 2 is a photomicrograph taken with a strobe light.

  FIG. 3 shows a state in which the deformed droplet 21a shown in FIG. 2 is gradually deflected from the initial flight direction and then travels on a flight path different from the other droplets 21a. Yes. Note that the flight path of the other droplets 21a is straight as originally. FIG. 3 is also a photomicrograph taken with a strobe light, similar to FIG.

  Further, FIG. 4 shows a state in which a similar pulse voltage is applied to the deflection electrode 15 at the timing when every other droplet 21 a passes near the tip of the deflection electrode 15. It can be seen that every other droplet 21a ejected continuously has its flight direction deflected. From this, it was proved that the flight direction of the droplet 21 a can be controlled by the flight direction control device 10. Further, from the flight path of the deflected droplet 21a, the angle between the original flight path and the flight path after deflection, that is, the deflection angle can also be measured.

  The inventor of the present invention changed the voltage applied to the deflection electrode 15 and measured the relationship between the voltage applied to the deflection electrode 15 and the deflection angle of the droplet 21a. FIG. 5 is a graph showing the measurement results.

  In FIG. 5, the point indicated by + indicates the measurement result. From this measurement result, it can be seen that the deflection angle of the droplet 21 a is proportional to the square of the voltage applied to the deflection electrode 15.

  Moreover, in FIG. 5, the curve shown with a dotted line is a curve which shows the theoretical formula obtained by calculating according to said Formula (1)-(4). From the curve and the point indicated by +, it can be seen that the measurement result agrees with the theoretical formula.

  Such a measurement result proves that the force acting on the droplet 21a is not the electrostatic force acting on the electric charge but the dielectric force acting on the dielectric, that is, Maxwell stress.

  Subsequently, the inventors of the present invention conducted a similar experiment using a silicone oil having ten times the viscosity of pure water as the liquid 21 instead of pure water, and obtained similar results. I was able to. The silicone oil is a commercially available silicone oil manufactured by Shin-Etsu Chemical Co., Ltd. (trade name: Shin-Etsu Silicone, product name: KF-96L-10cs, component: dimethylpolysiloxane, kinematic viscosity 10 [cSt], viscosity. 10 [mPa · s]).

  Subsequently, the inventor of the present invention uses an elongated plate-like member with a sharp tip, that is, a knife-edge-like member, instead of the rod-like or needle-like member, as the deflection electrode 15. Similar experiments were performed and similar results were obtained. The knife-edge-shaped member is a member having a tip thickness of 16.6 [μm] and a tip angle of 11.5 [degrees]. The liquid 21 is pure water. The thickness of the tip of the deflection electrode 15 is smaller than the interval between the adjacent droplets 21a.

  In FIG. 6, when a knife-edge-shaped member is used as the deflection electrode 15, the droplet 21 a on which Maxwell stress is applied by the voltage applied to the deflection electrode 15 is gradually deflected from the initial flight direction thereafter. The state of flying on a flight path different from that of the other droplets 21a is shown. Note that the flight path of the other droplets 21a is straight as originally. FIG. 6 is also a photomicrograph taken with a strobe light, similar to FIGS.

  In FIG. 6, a member having a pointed tip protruding downward from the upper edge is the head unit 11 used in the experiment. The droplet 21a flies downward, and the deflection electrode 15 is a droplet. Note that it is located on the right side of the flight path 21a, with its tip facing left and slightly upward. In the example shown in FIG. 6, the droplet 21a has a diameter of 50 [μm], a velocity of 5 [m / s], and an interval of 240 [μm].

  As described above, in this embodiment, a voltage is applied to the deflection electrode 15 disposed in the vicinity of the flight path of the droplet 21a ejected into the space to generate a non-uniform electric field in the space around the flight path. The flying direction of the droplet 21a is controlled in a non-contact manner by the dielectric force acting on the droplet 21a by the electric field. Thereby, even if it is the droplet 21a which consists of material which does not have electroconductivity, a flight direction can be controlled by non-contact. Further, it is not necessary to apply electric charge even to the droplet 21a made of a material having conductivity. Therefore, a device for applying electric charge is unnecessary, the configuration of the flight direction control device 10 can be simplified and reduced in size, and the cost can be reduced. Further, no time is required for applying the charge, and the flight direction can be controlled even for the droplets 21a ejected at a high speed.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

  The present invention can be applied to a control method and control device for the flying direction of a flying object.

DESCRIPTION OF SYMBOLS 10 Flight direction control apparatus 11a Nozzle 15 Deflection electrode 16 Voltage application apparatus 21a Droplet 21b Liquid column

Claims (10)

A method for controlling the flying direction of a flying object that is injected into the atmosphere or vacuum and flies,
The flying object is a droplet;
By applying a voltage to a control electrode disposed in the vicinity of the flight path of the droplet, an uneven electric field is generated in the space around the flight path;
A method for controlling a flying direction of a flying object, wherein the flying direction of the droplet is controlled in a non-contact manner by a dielectric force acting on the droplet by the electric field.   The method for controlling the flying direction of a flying object according to claim 1, wherein the flying direction of the droplet is controlled while the droplet is flying in the atmosphere or in a vacuum.   The method of controlling a flying direction of a flying object according to claim 1, wherein the droplet is formed by splitting a continuous liquid column ejected from a nozzle.   The method for controlling the flying direction of a flying object according to any one of claims 1 to 3, wherein a diameter of the range covered by the dielectric force is smaller than an interval between adjacent droplets.   The method for controlling the flying direction of a flying object according to claim 1, wherein the droplets are not charged.   6. The flight direction of a plurality of droplets that fly continuously is selectively controlled by applying a voltage to the control electrode at a timing when a desired droplet passes in the vicinity of the control electrode. The method for controlling the flying direction of a flying object according to any one of the preceding claims.   The method for controlling the flying direction of a flying object according to claim 1, wherein the droplet has a diameter of 0.5 [mm] or less. A control device for the flying direction of a flying object that is injected into the atmosphere or vacuum and flies,
The flying object is a droplet;
A control electrode disposed near the flight path of the droplet;
A voltage applying device for applying a voltage to the control electrode;
The voltage application device applies a voltage to the control electrode to generate a non-uniform electric field in the space around the flight path,
An apparatus for controlling a flying direction of a flying object, wherein the flying direction of the droplet is controlled in a non-contact manner by a dielectric force acting on the droplet by the electric field.   The control electrode has a rod-like or needle-like shape with a pointed tip, and the tip is disposed so as to be located in the vicinity of the flight path with a diameter smaller than an interval between adjacent droplets. The flying object control apparatus according to claim 8.   9. The control electrode has a plate-like shape with a sharp tip, and the tip is disposed so that its thickness is smaller than an interval between adjacent droplets and is located in the vicinity of the flight path. The flying direction control device of the flying object according to 1.