JP2000158364A - Method and device for ultrasonic non-contact micromanipuration using plurality of sound source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent microobjects from being limited in a region surrounded by oscillators and a reflective plate by trapping microobjects suspended in a liquid medium into a sound pressure node in a standing-wave sound-field and controlling an electric signal for driving the trapped microobjects to move them two-dimensionally. SOLUTION: In a liquid medium 18 where many microobjects 14 are dispersed and suspended, three ultrasonic oscillators 11a, 11b, 11c are arranged a given interval spaced so that they cross at one point 13 in the liquid medium 18 of respective sound shafts 12a, 12b, 12c. A given electric signal is impressed to each of ultrasonic oscillators 11a-11c to generate respective ultrasonic waves 15a-15c, and a sound field 16 of a standing wave is formed near cross region of each ultrasonic wave. In this sound field 16, the microobjects 14 are trapped into a sound pressure node in the sound field 16, these trapped microobjects 14 are two-dimensionally moved on a surface same as each of ultrasonic oscillators 11a-11c with changing phase of the electric signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic non-contact micro using a plurality of sound sources of three or more than four sound sources capable of capturing a minute object in a liquid medium and moving two-dimensionally or three-dimensionally. The present invention relates to a manipulation method and a device therefor.

[0002]

2. Description of the Related Art Conventionally, a micromanipulation method for handling a minute object has been strongly demanded in the fields of biotechnology, material development, micromachine, and the like, and a mechanism for handling an object on a conventional scale has been required. Scale-down method, method using static electricity, method using radiation pressure of laser light,
Methods using ultrasonic waves and the like have been proposed.

In these proposed techniques for handling small objects, micromanipulation using ultrasonic waves can be applied in a medium that propagates sound waves, and the target object has an acoustic impedance that is acoustically different from the medium. Anything that reflects or absorbs sound waves may be used.There are several advantages, such as a wide range of objects to be micromanipulated, and the ability to apply force only to a small region on the order of wavelength. Have.

[0004] The inventors of the present invention have proposed, as micromanipulation using the above-mentioned ultrasonic wave, (1) a method of setting a frequency in a standing wave sound field generated by installing a reflector at a focal position using a concave type vibrator. (Japanese Patent No. 2700058) has proposed a method of moving a minute object captured in a node of sound pressure one-dimensionally on a sound axis by changing the sound pressure. Then, (2)
A method has been proposed in which a rear surface electrode of an ultrasonic transducer is divided into a plurality of strips and a voltage is sequentially applied to the divided electrodes, thereby moving a minute object in an electrode arrangement direction (Patent No. 2).
No. 723182). Then, (3) a method was proposed in which a vibrator obtained by dividing the back electrode into a plurality of parts was curved to two-dimensionally move a minute object captured at a node of sound pressure (Japanese Patent Application No. 9-279,976).
-287953). Further, (4) two flat plate vibrators are installed so that their sound axes cross each other, and a minute object is captured by using a standing wave generated near the intersection of the sound axes, and one-dimensionally. (Japanese Patent Application No. 10-93)
937).

[0005]

Among the methods of capturing and moving a minute object using the above ultrasonic wave, the methods (1) to (3) are:
Ultrasonic waves are radiated from the vibrator toward the reflector, and the minute object is captured by the sound pressure node of the standing wave sound field, and the frequency of the electric signal supplied to the vibrator is changed or a voltage is applied. The position of the node of the sound pressure is controlled by selecting the electrode, and the captured minute object is moved. However, since the standing wave sound field is generated only in a region surrounded by the vibrator and the reflector, the moving range of the minute object is also limited to the region where the standing wave sound field is generated.

In the method (4), two ultrasonic vibrators are arranged so that their sound axes intersect each other, and ultrasonic waves are emitted from the respective vibrators and generated near the intersection of the sound axes. A small object is captured by the node of the sound pressure of the standing wave sound field, the phase or frequency of the electric signal supplied to the pair of vibrators is changed to control the position of the node of the sound pressure, and the captured small object is moved. Let it. However, the movement of the minute object in this method is one-dimensional only in the lateral direction.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problem, and is limited to a region surrounded by a vibrator and a reflector, in which a small object captured at a node or an antinode of a sound pressure of a standing wave sound field is limited. Another object of the present invention is to provide an ultrasonic non-contact micromanipulation method and apparatus capable of moving two-dimensionally or three-dimensionally.

[0008]

SUMMARY OF THE INVENTION An ultrasonic non-contact micromanipulation method according to the present invention is characterized in that three or more ultrasonic vibrators intersect at one point in a liquid medium in which a minute object disperses and floats. Placed at a predetermined distance so as to drive the ultrasonic transducer with a predetermined electric signal, in the standing wave sound field generated near the intersection of the sound axes of the emitted ultrasonic waves, The method captures a minute object in a medium at a node or an antinode of the sound pressure in the sound field, and controls the driving electric signal to move the captured minute object two-dimensionally or three-dimensionally. And Further, the ultrasonic non-contact micromanipulation device according to the present invention comprises three components arranged such that the sound axes thereof intersect at one point in the liquid medium while maintaining a predetermined interval in the liquid medium in which the minute object is dispersed. Or more ultrasonic transducers, and means for supplying a predetermined electric signal to the ultrasonic transducers, and a sound pressure in a standing wave sound field generated in the vicinity of the intersection of the emitted ultrasonic waves. A minute object in the medium is captured at a node or an antinode, and the captured minute object is moved two-dimensionally or three-dimensionally by controlling an electric signal supplied to the vibrator.

The position of the standing wave sound field is electrically controlled by changing the phase of the electric signal supplied to the ultrasonic vibrator or by giving a difference in the frequency, so that the position of the node or antinode of the sound pressure can be changed. By moving three-dimensionally or three-dimensionally, the captured minute object also moves two-dimensionally or three-dimensionally.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 shows a principle diagram of an ultrasonic non-contact micromanipulation method using three sound sources according to the present invention, in which a large number of minute objects 14 are dispersed in a floating liquid medium 18.
Each of the ultrasonic transducers 11a, 11b, and 11c has one sound axis 12a, 12b, and 12c in the liquid medium.
3 are arranged at predetermined intervals so as to intersect.

The three ultrasonic transducers 11a, 11b,
When a predetermined electric signal is supplied to 11c, ultrasonic waves 15a, 15b, and 15c oscillate from the three vibrators, respectively.
A standing wave sound field 16 is formed near the intersection area of the three ultrasonic waves. FIG. 2 is an enlarged explanatory view of the sound field 16 of the standing wave, and shows three ultrasonic waves 15a, 15b, and 15 respectively.
c intersect to form an antinode 17 of the sound pressure. In the minute object, a minute object 14a (generally solid) having a higher density than the medium and having a fast sound propagation receives a repulsive force from the antinode 17 of the sound pressure. Captured by the nodes of the sound pressure existing between the belly, the density is lower than the medium,
The minute object 14 b (for example, a bubble) having a slow sound propagation is captured by the antinode 17 of the sound pressure.

The ultrasonic transducers 11a, 11b, 11c
For example, a flat circular ultrasonic transducer having the same resonance frequency and the same output intensity can be used. The arrangement of the three transducers can be determined by considering the balance of the force and the phase change amount due to the ultrasonic wave, the moving distance and the moving direction of the minute object, and the intersection 13 of the sound axes.
The control is facilitated by arranging them at target positions with respect to. However, as will be described later, it is not always necessary to dispose them on the target. Here, the target position means that the vibrator is located at each vertex of the equilateral triangle, and the intersection of the sound axes is located at the center of the equilateral triangle.

As shown in FIG. 3A, the three ultrasonic transducers 11a, 11b, 11c are connected to their sound axes 12a,
By arranging 2b and 12c so as to face in the horizontal direction, the intersection 13 of the three sound axes is located on the same plane as the vibrator, and is formed near the intersection 13 of the sound axes due to the emission of ultrasonic waves. The minute object floating in the sound field of the standing wave is captured by the node of the sound pressure, and by changing the phase or frequency of the electric signal supplied to the vibrator, the captured minute object is flush with the vibrator. It will move two-dimensionally above. still,
In the above description, the case where each vibrator and each sound axis are on the same horizontal plane has been described. However, if each vibrator and each sound axis are on the same plane, they need not necessarily be horizontal.

The three ultrasonic transducers 11a, 11b,
As shown in FIG. 3B, 11c can be inclined at a predetermined angle so that the intersection 13 of the sound axes 12a, 12b, 12c can be positioned above a plane including the vibrator. In this case, it is possible to two-dimensionally move the minute object on a plane 19 parallel to the plane on which the vibrator on which the sound axis intersection 13 is located is provided. For example, in a region partitioned by a polymer film that propagates sound waves, three sound waves are irradiated from one surface without arranging a vibrator in the periphery, and sound is generated in a region where a small object is to be manipulated. By crossing the axes, it becomes possible to operate the minute object in the above-mentioned partitioned area. Therefore, the height of the intersection of the sound axes of the three ultrasonic transducers is determined based on the position at which the minute object in the medium is captured and moved.

The antinode 17 of the sound pressure formed in the sound field 16 of the standing wave
, The interference of three ultrasonic waves is considered for every two sound waves. FIG. 4A shows the interference of sound waves when a predetermined electric signal is applied to the ultrasonic transducers 11b and 11c and the ultrasonic waves 15b and 15c are emitted. Each two ultrasonic 15b,
15c intersect to form antinodes 17 of sound pressure at an interval of λ / (2 sin θ) (λ is the wavelength of the sound wave, and θ is half the crossing angle of the sound axis).

When the electric signals supplied to the two vibrators are controlled to change the phases of the ultrasonic waves to each other, the antinode 17 of the sound pressure moves. FIG. 4B illustrates the interference of the sound waves when the phase of the ultrasonic waves of the transducer 11c is slightly advanced. Since the phase of the ultrasonic wave of the transducer 11c has advanced, the antinode of sound pressure 1
7 is Δl in a direction from the vibrator 11c to the vibrator 11b.
Just moving.

A similar phenomenon occurs as shown in FIGS. 5 (a) and 5 (b). The interference of the two ultrasonic waves between the three ultrasonic transducers 11a, 11b and 11c causes the antinode of the sound pressure to decrease. 17 are generated, and nodes of sound pressure are formed between antinodes 17 of sound pressure at continuous hexagonal positions as shown in FIG. FIG.
(C) is the same as FIG. 4 and is shown for comparison with FIGS. 5 (a) and 5 (b). In FIGS. 1 and 2, a plurality of minute objects are shown floating and trapped in the medium 18. However, one minute object arbitrarily put into the medium may be trapped and moved. It is possible.

Next, consider changing the phase of the ultrasonic wave of one of the three ultrasonic transducers. When the phase of the vibrator 11c is advanced, the antinode 17 of the sound pressure due to the interference of the ultrasonic waves from the vibrator 11a and the vibrator 11c moves in the direction from the vibrator 11c to the vibrator 11a (FIG. 5).
(B)) The antinode 17 of the sound pressure (FIG. 5C) due to the interference between the vibrator 11b and the vibrator 11c moves in the direction from the vibrator 11c toward the vibrator 11b. Three vibrators 11a,
The movement of the antinode of the sound pressure due to the interference of the three sound waves 11b and 11c is represented by a composite vector of the two vectors going in the two directions. FIG. 6 shows three ultrasonic transducers 11a, 11b, and 11c.
As shown in (a), if the sound axes are arranged at the vertices of an equilateral triangle and the sound axes intersect at the center of the triangle, the movement vector of the antinode 17 of the sound pressure when the ultrasonic phase of the transducer 11c is advanced. Is
It overlaps with the sound axis 12c of the ultrasonic wave of the transducer 11c, and has a phase of 3
The moving distance when changing by 60 ° is 2λ / 3. However,
As shown in FIG. 6B, the angle formed by the sound axes 12a and 12b of the vibrators 11a and 11b is 150 °,
The angle formed by the sound axes 12a and 12c of the a and 11c is 15
If the three transducers are not arranged at the vertices of an equilateral triangle, such as 0 ° and the angle formed by the sound axes 12b and 12c of the transducers 11b and 11c is 60 °, the ultrasonic wave of the transducer 11c The movement vector of the node of the sound pressure when the phase is advanced is a movement vector obtained by combining the movement vectors of the antinodes 17 of the sound pressure between the transducers 11c and 11b and between the transducers 11c and 11a (FIG. b)). As described above, the nodes of the sound pressure exist between the antinodes of the sound pressure. When the sound field is changed and the antinode of the sound pressure is moved, the nodes of the sound pressure also move at the same time. As an application example of this device, operation of solid particles is mainly considered,
Generally, solid particles are trapped in the nodes of sound pressure, so
For the sake of simplicity, a case where a minute object is captured in a node of sound pressure will be described.

When a slight difference is given to the frequency of one ultrasonic wave, it is equivalent to a case where the phase of the ultrasonic wave is continuously changed at a constant speed. For example, when the frequency difference is 1 Hz, it corresponds to the phase changing continuously at a constant speed of 360 ° per second. Therefore, when a slight difference is given to the frequency, the nodes of the sound pressure move continuously at a constant speed, and the minute objects captured by the nodes of the sound pressure move at the same speed as the nodes of the sound pressure move. Moving.

When the phases of the ultrasonic waves radiated from the two ultrasonic transducers are simultaneously changed, the combined vector of the movement vector of the node of the sound pressure due to the change in the phase of the ultrasonic wave of each of the transducers. Move in the direction. For example, in FIG. 7A in which the vibrators are arranged at the vertices of an equilateral triangle, if the phase of each vibrator is independently changed, the node of the sound pressure moves in the sound axis direction of each vibrator. Two vibrators 1
Phase change Δ of ultrasonic waves 15b and 15c of 1b and 11c
When φ ₁ and Δφ ₂ are changed by the same size Δφ (FIG. 7)
(B)), a composite vector (Δ
(x, Δy) in the direction of the sound axis 12a of the transducer 11a (advancing the phases of the ultrasonic waves 15b and 15c by the same magnitude is equivalent to relatively delaying the phase of the ultrasonic wave 15a). When the phases of the ultrasonic waves 15b and 15c are changed by the same magnitude Δφ in different directions (signs are reversed), the ultrasonic waves can be moved in a direction perpendicular to the sound axis 12a of the vibrator 11a (see FIG. c)).

As described above, by arbitrarily changing the phase of the two ultrasonic waves, it becomes possible to move the standing wave sound field in an arbitrary direction in two dimensions, and the minute object captured by the sound wave node Also moves with it.

FIG. 8 is a schematic diagram of an ultrasonic non-contact micromanipulation method using four sound sources according to the present invention, wherein four ultrasonic vibrators 11a, 11b, 11c, and 11d are arranged at predetermined intervals so that their sound axes 12a, 12b, 12c, and 12d intersect at a single point 13 in the liquid medium.

FIG. 8A shows an example in which the four ultrasonic transducers are arranged at the vertices of a regular triangular pyramid, and the intersection of the sound axes is set at the center of the regular triangular pyramid. When a predetermined electric signal is supplied to each of the four ultrasonic transducers, ultrasonic waves 15a, 15b, 15c, and 15d are oscillated from the four transducers, respectively.
A sound field of a standing wave is formed in the vicinity of the intersection area of the ultrasonic waves, similar to the case where three transducers are arranged, and a small object floating in the sound field at a node of the sound pressure is formed. Capture. Changing the phase of one electrical signal of the four ultrasonic transducers,
Alternatively, when the frequency is slightly shifted, the sound field moves in the direction of the sound axis, and the minute object captured by the node of the sound pressure moves.
Also, like the two-dimensional movement by three ultrasonic waves, the phase of a plurality of (two or three) ultrasonic waves changes in the case of four ultrasonic waves.
Alternatively, when the frequency is slightly shifted, the moving vector moves in the direction of the combined vector of the moving vectors moving in the direction of each sound axis. That is, three-dimensional movement is possible by changing three ultrasonic waves. FIG. 8B shows a case where one of the four transducers 11d is moved on its sound axis and arranged on the same plane as the remaining three transducers. In this case as well, the same operation of moving the minute object is possible, and as in the case of the three ultrasonic waves described above, the ultrasonic waves in four directions from one surface cross the partitioned area. Thus, a three-dimensional movement operation can be performed.

As the ultrasonic transducer, a flat circular ultrasonic transducer having the same output intensity and resonance frequency can be used. The arrangement of the four transducers can be easily controlled by making the intervals around the sound axis intersection 13 in consideration of the balance of the force by the ultrasonic waves, the amount of phase change, the moving distance, and the moving direction. If the sound axes intersect at a single point, it is not necessary to position the sound axes at the vertices of the regular triangular pyramid as shown in FIG.
It is not necessary to be located on the same plane as shown in FIG.

If five or more ultrasonic transducers are arranged so that their sound axes intersect at one point, a standing wave sound field is formed near the intersection by the emission of ultrasonic waves, and the electric signal supplied to each transducer , It is possible to move the formed standing wave sound field three-dimensionally, as in the case of four units.

FIG. 9 is a block diagram showing an embodiment of the micromanipulation device according to the present invention. 3
The ultrasonic transducers 11a, 11b, and 11c are fixed in a water tank 20 containing water as a liquid medium 18 so that the sound axes 12a, 12b, and 12c of the respective transducers intersect at one point. The sine wave AC voltage from 21 is amplified by the power amplifier 22 and applied to the three vibrators to radiate ultrasonic waves into the liquid medium 18. Ultrasonic waves 15a, 15b, and 15c having the same wavelength are emitted from the three transducers, and a standing wave sound field 16 is formed near the intersection of the sound axes. In addition, 14 is a minute object to be captured floating in the medium.

FIG. 10 shows that a sine wave alternating current having a frequency of 1.75 MHz is generated using a function generator, amplified by a power amplifier, supplied to three ultrasonic transducers, and the formed standing wave sound field is subjected to a Schlieren method. It is explanatory drawing visualized using. Near the intersection of the sound axes of the three vibrators, a honeycomb-like hexagonal pattern of light and dark was observed, indicating that a standing wave sound field was formed. The contrast of the Schlieren image corresponds to the antinodes (bright) and nodes (dark) of the sound pressure.

When a suspension in which polystyrene particles having an average diameter of 0.3 mm were suspended in the standing-wave sound field was injected using a pipette, the polystyrene particles were captured at nodes of sound pressure. A node of sound pressure is generated at the position of a vertex of a continuous hexagonal pattern, and captures a solid minute object. The center of the hexagon has an antinode of sound pressure, and a repulsive force acts on the solid particles. That is, it is considered that the solid particles receive a force from the center of the hexagon to the apex, and if the particles already exist there, the solid particles aggregate to form the sides of the hexagon. If three vibrators are arranged at the vertices of an equilateral triangle and the intersection of sound axes intersects at the center of the triangle, the phase of the voltage applied to each vibrator is changed to reduce the sound pressure node. Can be moved on a line parallel to the sound axis of each transducer, and at the same time, the captured particles also move. Also, if a slight difference is given to the frequency, it is equivalent to the phase changing continuously at a constant speed, and thus the captured particles can be moved at a constant speed.

FIG. 11 shows 1.75 MHz (λ = 0.75 MHz) in water.
In the sound field generated by setting the angle 2θ formed by the sound axis to the sound axis of 857 mm as 120 ° and giving a difference of 0.5 Hz to the frequency, the particles move at intervals of 4 seconds (phase change: 720 ° / 4).
(Equivalent to seconds). First, the three vibrators were driven at 1.75 MHz and an AC voltage of about 20 Vpp, and when the particles were injected, three particles were continuously captured below the photograph. The trapped shape of the particles is considered to be along the side including one vertex of the hexagonal sound pressure node. Only the frequency of the electric signal applied to the upper vibrator is 1.7499995 MHz (frequency difference 0.5 Hz,
That is, when the phase was changed to 180 ° / sec, the particle group moved upward at a constant speed of 0.29 mm / sec (corresponding to λ / 3). Next, the frequency of the electric signal supplied to the upper vibrator was returned to 1.75 MHz, and the frequency of the electric signal of the lower left vibrator was similarly changed to 1.7499999 MHz.
Then, the particle group moved to the lower left and moved at the same speed.
Thus, it is shown that the position of the particle can be controlled two-dimensionally by controlling the frequency between the vibrators.

[0030]

As described above, the ultrasonic non-contact micromanipulation method and apparatus using a plurality of sound sources according to the present invention captures a small object in a liquid medium in a non-contact manner and detects differences in phase change and frequency. It is possible to move by holding it. When three vibrators are used, the moving direction can be controlled two-dimensionally and three-dimensionally by using four or more vibrators. When each oscillator is arranged at each vertex of an equilateral triangle or an equilateral triangular pyramid, and arranged so that the sound axes intersect at the center, respectively, by changing the phase or frequency of each oscillator, it is parallel to each sound axis. The small object captured in the direction can be moved.

[Brief description of the drawings]

FIG. 1 is a principle diagram of an ultrasonic micromanipulation method according to the present invention.

FIG. 2 is an explanatory diagram of a state in which a minute object is captured at a node or antinode of a sound pressure in a standing wave sound field.

FIG. 3 is an explanatory diagram of positions of intersections of sound axes of three ultrasonic transducers.

FIG. 4 is an explanatory diagram showing formation of antinodes of sound pressure due to interference of ultrasonic waves by two sound sources, and movement of antinodes of sound pressure when the phase is changed.

FIG. 5 is an explanatory diagram showing a state of formation of a sound pressure antinode for each of two sound sources.

FIG. 6 is an explanatory diagram showing a state of antinodes of sound pressure when three ultrasonic transducers are arranged at the vertices of an equilateral triangle and when they are not.

FIG. 7 shows a second example of a sound pressure node due to a phase change of ultrasonic waves of two sound sources.
It is explanatory drawing which shows a dimension movement.

FIG. 8 is an explanatory diagram of an arrangement state of four ultrasonic transducers and an intersection position of a sound axis.

FIG. 9 is a block diagram of the micromanipulation device of the present invention.

FIG. 10 is a photograph of a schlieren image of a standing wave sound field formed near an intersection of sound axes.

FIG. 11 is a multiple exposure photograph showing the state of movement of fine particles performed in an example.

[Explanation of symbols]

11a, 11b, 11c, 11d Ultrasonic vibrator 12a, 12b, 12c, 12d Sound axis of ultrasonic vibrator 13 Intersection of sound axis 14 Micro object 15a, 15b, 15c, 15d Ultrasonic wave 16 Standing wave sound field 17 Sound pressure Belly 18 medium 21 function generator 22 power amplifier

Claims (12)

[Claims] In a liquid medium in which a minute object is dispersed, three ultrasonic vibrators are arranged at a predetermined distance so that their sound axes intersect at one point in the liquid medium. The ultrasonic vibrator is driven by a predetermined electric signal, and is radiated.
A micro object in the above medium is captured at the node or antinode of the sound pressure of the standing wave sound field generated near the intersection area of two ultrasonic waves, and the micro object captured by controlling the driving electric signal is two-dimensional Ultrasonic non-contact micromanipulation method characterized in that it moves in a dynamic manner. 2. A standing wave sound field is formed by inclining the sound axes of ultrasonic waves emitted from the three ultrasonic transducers and crossing the sound axes outside a plane including the three transducers. The ultrasonic non-contact micromanipulation method according to claim 1, wherein: 3. The ultrasonic non-contact micro device according to claim 1, wherein at least one of the three ultrasonic transducers is driven by supplying an electric signal having a different phase. Manipulation method. 4. The ultrasonic non-contact micromanipulation according to claim 1, wherein at least one of the three ultrasonic transducers is driven by supplying an electric signal having a different frequency. Method. 5. Three ultrasonic vibrators arranged so that their sound axes intersect at one point in the liquid medium while maintaining a predetermined interval in the liquid medium in which the minute object exists;
Means for supplying a predetermined electric signal to the plurality of ultrasonic transducers, and a node or an antinode of the sound pressure of the standing wave sound field generated in the vicinity of the intersection of the three radiated ultrasonic waves. An ultrasonic non-contact micromanipulation device characterized in that a minute object is captured and an electric signal supplied to the vibrator is controlled to move the captured minute object two-dimensionally. 6. The ultrasonic transducer according to claim 1, wherein the three ultrasonic transducers are arranged at a predetermined inclination above a plane including the three transducers so that their sound axes intersect. Item 6. An ultrasonic non-contact micromanipulation device according to item 5. 7. A method according to claim 1, wherein four or more ultrasonic vibrators are placed in a liquid medium in which a minute object is present at a predetermined distance such that their sound axes intersect at one point in the liquid medium. The above ultrasonic vibrator is driven by a predetermined electric signal, and a minute object in the medium is formed at a node or antinode of a sound pressure of a standing wave sound field generated near an intersection area of four or more ultrasonic waves to be radiated. An ultrasonic non-contact micromanipulation method, characterized in that a small object that is captured is controlled three-dimensionally by controlling an electric signal for capturing and driving the object. 8. The apparatus according to claim 7, wherein the four or more ultrasonic transducers are arranged on the same plane, and arranged so that sound axes intersect outside a plane including the transducers. Ultrasonic non-contact micromanipulation method. 9. The ultrasonic non-transmission device according to claim 7, wherein at least one of the four or more ultrasonic transducers is driven by supplying an electric signal having a different phase. Contact micromanipulation method. 10. The ultrasonic non-contact micro device according to claim 7, wherein an electric signal having a different frequency is supplied to at least one of the four or more ultrasonic transducers to drive them. Manipulation method. 11. Four or more ultrasonic vibrators arranged so that their sound axes intersect at one point in the liquid medium while maintaining a predetermined interval in the liquid medium in which the minute object exists;
Means for supplying a predetermined electric signal to the four or more ultrasonic transducers, and a node or antinode of a sound pressure of a standing wave sound field generated in the vicinity of the intersection of the four or more ultrasonic waves to be radiated. An ultrasonic non-contact micromanipulation apparatus characterized in that a micro object in the medium is captured, an electric signal supplied to the vibrator is controlled, and the captured micro object is moved three-dimensionally. 12. The ultrasonic transducer according to claim 1, wherein the ultrasonic transducers are arranged at a predetermined inclination so that their sound axes intersect above a plane including the transducers. The ultrasonic non-contact micromanipulation device according to claim 11.