JP6145749B2 - Deformable liquid crystal moving body - Google Patents

Description

  The present invention relates to a deformable liquid crystal moving body.

Conventionally, liquid crystals have been used in information display devices such as liquid crystal displays because their optical properties change as liquid crystal molecules are aligned.
In recent years, techniques for generating liquid crystal flow by applying an electric field or a magnetic field to liquid crystal molecules have been developed (Patent Documents 1 to 5).

  The techniques of Patent Documents 1 to 5 are based on the principle of generating a liquid crystal flow due to a velocity gradient generated around the liquid crystal molecules due to the rotation of the liquid crystal molecules. Can be generated. That is, according to the techniques of Patent Documents 1 to 5, the liquid crystal can be moved by generating a flow in the liquid crystal.

Japanese Patent No. 3586734 Japanese Patent No. 4273341 JP 2009-185993 A JP 2009-185994 A JP 2010-183754 A

  However, in the techniques of Patent Documents 1 to 5, since a flow is generated in the liquid crystal by applying an electric field to the liquid crystal from a pair of electrodes arranged so as to sandwich the liquid crystal, a path for moving the liquid crystal In this case, a pair of electrodes must be arranged so as to sandwich the liquid crystal. That is, in the techniques of Patent Documents 1 to 5, the path for moving the liquid crystal is limited to the place where the electrode is provided. In other words, in the techniques of Patent Documents 1 to 5, the liquid crystal can be moved only along a predetermined route.

  In view of such circumstances, an object of the present invention is to provide a deformable liquid crystal moving body that can freely move on a plane.

The deformable liquid crystal moving body of the first invention is a moving body using liquid crystal flow as a driving source, and a container enclosing liquid crystal, an electrode and / or a magnetic pole provided on the inner surface of the container, and selection And a controller that generates an electric field and / or a magnetic field between the applied electrode and / or the applied magnetic pole, wherein the container is formed of a flexible member.
The deformable liquid crystal moving body of the second invention is characterized in that, in the first invention, the container is a sheet-like member formed into a bag shape.

According to the first aspect of the present invention, if an electric field and / or magnetic field is generated between the selected applied electrodes and / or applied magnetic poles by the control unit, the liquid crystal liquid crystal positioned between the applied electrodes and / or between the applied magnetic poles. The molecule changes its orientation so that its axial direction is in a predetermined direction with respect to the electric field lines of electric field and / or the magnetic field lines of magnetic field. Then, liquid crystal flow is generated in the liquid crystal in the container. And since the container is formed with the member which has a softness | flexibility, a container changes the shape by a liquid-crystal flow. Then, the moving body moves with the shape change of the container. Therefore, if the liquid crystal flow generated in the liquid crystal is adjusted, the moving body can be moved in a desired direction.
According to the second invention, since the electrode and / or the magnetic pole is formed on the surface of the sheet-like member and the sheet-like member is formed into a bag shape, the liquid crystal moving body can be easily manufactured.

It is a schematic explanatory drawing of the deformable liquid crystal moving body 1 of this embodiment, (A) is a schematic side view, (B) is a schematic plan view. It is a schematic explanatory drawing of the movement condition of the liquid crystal mobile body 1 which can deform | transform this embodiment. It is a schematic explanatory drawing of the deformable liquid crystal moving body 1 of other embodiment.

Next, an embodiment of the present invention will be described with reference to the drawings.
In addition, in each figure, in order to make the structure of each part intelligible, the relative dimension of each part does not correspond with an actual thing.

(Liquid crystal moving body 1 of this embodiment)
First, a deformable liquid crystal moving body 1 according to this embodiment will be described with reference to FIG.
As shown in FIG. 1, the deformable liquid crystal moving body 1 of the present embodiment includes a container 2, an electrode 3, a control unit 5, and a liquid crystal 10.
Hereinafter, components of the deformable liquid crystal moving body 1 of the present embodiment will be described. Hereinafter, the deformable liquid crystal moving body 1 is simply referred to as a liquid crystal moving body.

(Liquid crystal 10)
In FIG. 1, reference numeral 10 indicates a liquid crystal accommodated in the container 2. The liquid crystal 10 is accommodated in the container 2 so that it can freely flow. The liquid crystal moving body 1 of the present embodiment is configured such that the liquid crystal moving body 1 of the present embodiment can move by generating liquid crystal flow in the liquid crystal 10 and using the liquid crystal flow as a power source.

  In addition, the liquid crystal 10 used for the liquid crystal moving body 1 of this embodiment is not specifically limited. For example, a nematic liquid crystal, a smectic liquid crystal, a cholesteric liquid crystal, a discotic liquid crystal, and the like are not particularly limited as long as the liquid crystal molecules rotate when an electric field or a magnetic field is applied.

(Container 2)
As shown in FIG. 1, the container 2 is a sheet-like member formed in a bag shape, and has a space in which the liquid crystal 10 can be accommodated. The sheet-like member that forms the container 2 is formed of a material that is flexible enough to be deformed when the liquid crystal 10 moves inside. For example, when a liquid crystal flow is generated inside the liquid crystal 10, the container 2 is formed of a material having flexibility enough to swell or bend by the flow.

  In addition, the raw material of the sheet-like member which forms the container 2 will not be specifically limited if it has the softness | flexibility as mentioned above. In particular, as described later, it is preferable that the electrode 3 or the like can be formed on the surface by a method such as sputtering. As such a material, for example, a polymer thin film or a gel can be employed.

(Electrode 3)
As shown in FIG. 1, a plurality of electrodes 3 are provided on the inner surface of the container 2. The plurality of electrodes 3 are formed using, for example, a conductor such as ITO, copper, or silver as a material. The respective electrodes 3 are provided so as to be arranged along the inner surface of the container 2 (for example, see FIG. 1B so as to form a lattice shape) so that the adjacent electrodes 3 are separated from each other. Is formed. In other words, the plurality of electrodes 3 are formed such that adjacent electrodes 3 are electrically insulated from each other.

  Note that, in the plurality of electrodes 3 provided on the same sheet-like member, the distance between the adjacent electrodes 3 is such that an electric field EF is formed between the electrodes 3 when a voltage is applied between the electrodes 3. The distance is not particularly limited.

  Further, in the plurality of electrodes 3 provided on the same sheet-like member, the distance between the adjacent electrodes 3 is such that an electric field EF is formed between the electrodes 3 when a voltage is applied between the electrodes 3. The distance is not particularly limited.

(Control unit 5)
In the liquid crystal moving body 1 of the present embodiment, a control unit 5 (not shown) is attached to the container 2. The control unit 5 is electrically connected to the electrode 3 by wiring. The controller 5 has a function of selecting an electrode 3 (application electrode) to which a voltage is applied and controlling a voltage applied to the application electrode, its timing, cycle, and the like. That is, the control unit 5 adjusts the position where the electric field EF is formed, the timing when the electric field is formed, the strength of the electric field EF, and the like.

  In addition, control of the application electrode etc. by the control part 5 may be programmed in the control part 5, and may be controlled by the signal from the outside, and is not specifically limited.

(Alignment film 4)
An alignment film 4 is laminated on the surfaces of the plurality of electrodes 3. The alignment film 4 aligns liquid crystal molecules in the liquid crystal 10 in a predetermined direction. For example, the surface of the alignment film 4 is rubbed so that the liquid crystal molecules in the liquid crystal 10 are aligned perpendicular to the inner surface of the container 2.

  The liquid crystal molecules in the liquid crystal 10 are aligned because the liquid crystal molecules are rotated in a predetermined direction to generate a predetermined liquid crystal flow in the liquid crystal 10 when the electric field EF is applied to the liquid crystal 10. .

(Operation of liquid crystal moving body 1)
Since the configuration is as described above, the liquid crystal moving body 1 placed on a flat surface such as a floor or a table operates as follows. Hereinafter, the movement of the liquid crystal moving body 1 will be described with reference to FIG.
In the circled circle in the figure, a schematic explanatory diagram of the movement of the liquid crystal molecules m in the liquid crystal 10 is shown.

  FIG. 2A shows a state in which no voltage is applied between the electrodes 3 of the liquid crystal moving body 1 of the present embodiment. As shown in FIG. 2A, in the state where no voltage is applied between the electrodes 3, the container 2 has flexibility, so that the surface of the liquid crystal moving body 1 is caused by the surface tension of the liquid crystal 10. It becomes almost spherical.

  When a voltage is applied between the electrodes 3 from the state of FIG. 2A, an electric field EF is formed between the electrodes 3. Then, the formed electric field EF passes through the liquid crystal 10 in the container 2.

  At this time, the alignment film 4 aligns the liquid crystal molecules m in the liquid crystal 10 so that the alignment is perpendicular to the inner surface of the container 2, whereas the electric field EF formed between the electrodes 3. Is inclined with respect to the normal direction of the inner surface of the container 2 except for the vicinity of the inner surface of the container 2. For this reason, when the electric field EF is formed, the portion of the liquid crystal molecules m through which the electric field EF passes in the liquid crystal 10 has an axial direction that is perpendicular to the inner surface of the container 2. It rotates clockwise so as to be parallel to the direction of EF (see the inside of a circle in FIG. 2B). Then, the liquid crystal molecules m flow in the liquid crystal 10 with the rotation of the liquid crystal molecules m. For example, in FIG. 2, since the liquid crystal molecules m flow in the right direction, the liquid crystal 10 moves in the right direction. At this time, since the container 2 is formed of a flexible member, the container 2 is deformed by the flow of the liquid crystal molecules m, and the liquid crystal moving body 1 becomes a streamline that rises on the right side (front in the moving direction). The position of the center of gravity (that is, the position of the center of gravity of the liquid crystal 10) moves to the right side (see FIG. 2B).

  When the liquid crystal molecule m rotates until its axial direction becomes parallel to the direction of the electric field EF, the liquid crystal molecule m stops rotating in that state (see FIG. 2B). That is, even if the electric field EF continues to be applied to the liquid crystal 10, the flow of the liquid crystal molecules m in the liquid crystal 10 occurs only when the liquid crystal molecules m first rotate. For this reason, the electric field EF is applied to the liquid crystal 10 when the liquid crystal molecules m in the liquid crystal 10 no longer flow due to friction between the liquid crystal molecules or friction between the liquid crystal 10 and the inner surface of the container 2. However, the liquid crystal 10 stops moving. When the liquid crystal molecules m in the liquid crystal 10 no longer flow, the liquid crystal 10 returns to a shape before the electric field EF is applied from a streamlined shape (FIG. 2C).

  Here, in the liquid crystal moving body 1 in the streamlined state (the state in FIG. 2B), the position of the center of gravity has moved to the right from the original position (the position in FIG. 2A). For this reason, even if it returns to the shape before the electric field EF is applied, the position of the center of gravity moves to the right from the original position (the position in FIG. 2A).

  Therefore, when the electric field EF is applied to the liquid crystal 10, the liquid crystal moving body 1 is moved in the liquid crystal flow direction by the flow of the liquid crystal molecules m in the liquid crystal 10 (liquid crystal flow) due to the rotation of the liquid crystal molecules m of the liquid crystal 10. It can be made.

  If a voltage is intermittently applied to the electrode 3, the liquid crystal molecules m rotate each time the voltage is applied, and the liquid crystal flow can be intermittently generated in the liquid crystal 10. Then, when a voltage is intermittently applied to the electrode 3 so that liquid crystal flows along the same direction each time a voltage is applied, the liquid crystal moving body 1 is moved in the same direction (right in FIG. 2). Direction). Moreover, if the period for applying the voltage is shortened, the liquid crystal moving body 1 can be moved in a state close to continuous movement.

(About the moving direction of the liquid crystal moving body 1)
Further, in the liquid crystal moving body 1, the container 2 itself has a plurality of electrodes 3, and the moving direction is determined by the liquid crystal flow generated in the container 2, so that the application electrode 3 for applying a voltage is applied. Is adjusted, the liquid crystal moving body 1 can be moved in a desired direction.

  For example, as shown in FIG. 1, when a plurality of electrodes 3 are arranged in a grid pattern on the inner surface of the container 2, the liquid crystal moving body 1 is placed in a desired direction by selecting an application electrode to which a voltage is applied. Can be moved. That is, since the liquid crystal flow can be generated along the direction in which the application electrodes are arranged (that is, the direction of the electric field EF), the liquid crystal moving body 1 can be moved along that direction.

  For example, as shown in FIG. 1B, if the electrodes 3 arranged along the direction of the line SL are selected as the application electrodes, liquid crystal flow is generated along the line SL. Can be moved along. If the electrodes 3 arranged along the direction of the line LL are selected as application electrodes, the liquid crystal moving body 1 can be moved along the line LL.

(About the moving form of the liquid crystal moving body 1)
As described above, the liquid crystal moving body 1 can take the form of moving by generating liquid crystal flow so as to move the position of the center of gravity, but the moving form of the liquid crystal moving body 1 is not limited to such a form. For example, the liquid crystal moving body 1 can be moved even if the liquid crystal flow is generated so that the container 2 moves while deforming around the liquid crystal 10 (movement mode 2). Further, the liquid crystal moving body 1 can be moved (moving form) 3 even when the liquid crystal flow is generated so that the container 2 expands and contracts (the length in the left-right direction in FIG. 1 changes). In the case of the movement modes 2 and 3, the direction of liquid crystal flow and the direction of movement of the liquid crystal mobile body 1 do not necessarily coincide with each other. However, if the direction of liquid crystal flow is appropriately controlled, Can be moved.

  In the above example, the case where the electrode 3 is provided between the inner surface of the container 2 and the alignment film 4 has been described. However, the electrode 3 may be provided on the outer surface of the container 2 as long as an electric field EF that passes through the liquid crystal 10 can be formed when a voltage is applied. That is, only the alignment film 4 may be provided on the inner surface of the container 2, and the electrode 3 may be provided on the outer surface of the container 2. In this case, since the electrode 3 can be provided after the bag-like container 2 enclosing the liquid crystal 10 is formed, the degree of freedom of providing the electrode 3 in the container 2 can be increased.

(Manufacturing method of container 2)
Although the method for manufacturing the container 2 including the electrode 3 as described above is not particularly limited, for example, it can be formed by the following method.

First, a plurality of electrodes 3 are formed by forming a film of ITO or the like on the surface of a sheet-like member that is a material of the container 2 by a method such as sputtering or vacuum deposition. At this time, if masking is performed between positions where the plurality of electrodes 3 are formed, the plurality of electrodes 3 are formed on the surface of the sheet-like member while being electrically insulated from each other.
Next, the alignment film 4 is formed on the surface of the sheet-like member on which the plurality of electrodes 3 are formed by spin coating or the like. Then, a sheet-like member in which the plurality of electrodes 3 and the surface are covered with the alignment film 4 can be formed.
And if the sheet-like member in which the several electrode 3 and the alignment film 4 were formed is made into a bag shape, the container 2 can be formed.

  For example, when a sheet-like member is attached to the surface of a columnar or spherical mold or a columnar or spherical mold is pressed against the sheet-like member, the sheet-like member can be formed into a bag shape having an opening. When the sheet-like member is formed into a bag shape by such a method, the liquid crystal moving body 1 can be formed by putting liquid crystal into the bag through the opening and closing the opening.

  Of course, the method of forming the sheet-like member into a bag shape and the method of forming the liquid crystal moving body 1 are not limited to the above methods, and various methods can be employed.

  In addition, you may form the wiring for connecting the some electrode 3 and the control part 5 with the some electrode 3 with films | membranes, such as ITO. In this case, the wiring shape may be masked on the surface of the sheet-like member.

  Moreover, the electrode 3 can also be formed by applying an electrode material by an ink jet method or the like other than the method described above.

(Regarding the alignment film 4)
Furthermore, the alignment film 4 is not necessarily provided. For example, if the liquid crystal flow is always generated in a certain direction, it is necessary to provide the alignment film 4 to align the alignment of the liquid crystal molecules in the liquid crystal 10. However, if the liquid crystal flow in the liquid crystal 10 is increased, the surface of the sheet-like member is not provided with the alignment film 4 and is not subjected to the rubbing-less process, or is subjected to the weak anchoring process. It is preferable that Then, when the liquid crystal molecules in the liquid crystal 10 rotate or the liquid crystal 10 moves, the resistance between the liquid crystal 10 and the surface of the sheet-like member (that is, the inner surface of the container 2) can be reduced. The power can be increased. The weak anchoring process is an anchoring process described in Japanese Patent No. 4053530 “zero-plane anchoring liquid crystal alignment method and liquid crystal device thereof”, that is, horizontal or oblique alignment is forced, but in-plane (horizontal For example, anchoring without an alignment forcing force in the direction in the horizontal plane where the axis of the molecule is located.

  In order to increase the degree of freedom in the direction in which the liquid crystal flows in the liquid crystal 10, it is preferable not to provide the alignment film 4. In other words, in order to increase the degree of freedom in the direction in which the liquid crystal moving body 1 is moved, it is preferable not to provide the alignment film 4.

(A pair of sheet-like members 2a and 2b)
As shown in FIG. 3, the container 2 may be formed by stacking a pair of sheet-like members 2a and 2b on top of each other. Specifically, the outer edges of the pair of sheet-like members 2a and 2b may be joined in a liquid-tight manner with the outer edges overlapped to form the container 2. In the case of manufacturing by this method, the portion where the pair of sheet-like members 2a and 2b are bonded together is less flexible than the other portions. Then, since the bonded part is difficult to deform, it is desirable that the paired sheet-like members 2a and 2b have fewer bonded parts. For example, when the container 2 moves while deforming so as to go around the liquid crystal 10, the deformation of the container 2 is smooth if there are not many portions to be bonded together, so the movement of the liquid crystal moving body 1 is also smooth. Become. Even when moving while deforming as shown in FIG. 2 or when the liquid crystal moving body 1 moves while expanding and contracting (when moving while changing the length in the left-right direction in FIG. 1), the container 2 Since the deformation of the is smooth, it is desirable that there is less part to stick.

(Use of magnetic poles)
In the above example, the case where the electrode 3 is provided and a flow is generated in the liquid crystal 10 by the electric field EF has been described, but a magnetic pole may be provided instead of the electrode 3. In this case, as the liquid crystal 10, a liquid crystal whose orientation of liquid crystal molecules is changed by a magnetic field may be used.
Furthermore, when the liquid crystal 10 can change the orientation of liquid crystal molecules by both an electric field and a magnetic field, both electrodes and magnetic poles may be provided.

  The deformable liquid crystal mobile body of the present invention can be used as a transport means for transporting a drug to an affected part in a blood vessel or a living body, a transport means for transporting a minute object on a MEMS, or the like.

DESCRIPTION OF SYMBOLS 1 Liquid crystal moving body 2 Container 3 Electrode 4 Alignment film 5 Control part 10 Liquid crystal EF Electric field

Claims (2)

A moving body using liquid crystal flow as a driving source,
A container enclosing a liquid crystal;
An electrode and / or a magnetic pole provided on the inner surface of the container;
A control unit that generates an electric field and / or a magnetic field between selected application electrodes and / or application magnetic poles,
A deformable liquid crystal moving body, wherein the container is formed of a flexible member. The deformable liquid crystal moving body according to claim 1, wherein the container is a sheet-like member formed into a bag shape.

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