JP4643192B2 - Gripper - Google Patents

Description

The present invention relates to a gripper. In recent years, the need for gripping and manipulating micro objects such as micro samples on the micrometer scale, micro dust generated during processing of semiconductors and displays, and biological samples such as cells has increased due to technological advances. Has also been developed. In order to grip a micro object on the micrometer order, the gripper must also process the member that grips the micro object with micrometer order accuracy, and the member that grips the micro object operates on the micrometer order. I have to let it.
The present invention relates to a gripper used for grasping and manipulating a minute object on the order of micrometers.

  In a gripper used for gripping micro objects of micrometer order, as a mechanism for operating a member (hereinafter referred to as an arm) that grips micro objects, an arm that utilizes expansion due to self-heating of a material when energized is used. An actuator that moves the arm (hereinafter referred to as a thermal expansion actuator) or an actuator that moves the arm using an electrostatic force generated between a pair of electrodes (hereinafter referred to as an electrostatic actuator) is used (for example, Patent Document 1). 2).

FIG. 13A is a diagram showing an example of a gripper 100 driven by a thermal expansion actuator, FIG. 13B is a diagram showing an example of a gripper 110 driven by an electrostatic actuator, and FIG. It is explanatory drawing of the state which hold | gripped the micro object M with the conventional gripper.
As shown in FIG. 13A, the gripper 100 driven by the thermal expansion actuator includes a pair of arms 105 and 105 each having a grip portion 106 at the tip. The pair of arms 105, 105 includes a high expansion portion 102 connected to the outer end thereof and a low expansion portion 103 connected to the inner end thereof. The high expansion portion 102 and the low expansion portion 103 are It constitutes a thermal expansion actuator.
For this reason, when a voltage is applied between the pair of electrodes 104, 104, both the high expansion part 102 and the low expansion part 103 expand by self-heating, but the low expansion part 103 has a higher capacity than the high expansion part 102. Since the length is short and heat diffusion to the arm 105 is likely to occur compared to the high expansion portion 102, the amount of expansion is smaller than that of the high expansion portion 102. Then, a force is applied to the pair of arms 105, 105 so that the tip ends are pushed inward from the outside, and the low expansion portion 103 is bent as a fulcrum so that the gripping portions 106 approach each other. A minute object can be held between the pair of gripping portions 106 and 106.
Further, as shown in FIG. 13B, in the case of the gripper 110 driven by the electrostatic actuator, the base ends of the pair of arms 105 and 105 are connected to each other via the spring portion 111, Comb-shaped electrodes 116 and 117 are provided on the mutually opposing surfaces between the base ends of the arms 105 and 105, respectively. Then, when a voltage is applied between the comb-shaped electrodes 116 and 117, the comb-shaped electrodes 116 and 117 can be brought close to each other by the electrostatic force generated between the comb-shaped electrodes 116 and 117, and the pair of arms 105 and 105 are connected. Since the grip portion 106 can be swung so as to approach each other with the spring portion 111 as a fulcrum, a minute object can be held between the pair of grip portions 106 and 106.

By the way, there are various shapes and materials of minute objects, and the gripper is easy to grasp depending on the shape. Soft objects and objects with many flat parts are relatively easy to grasp, but have attracted attention in recent years, for example, micro objects with a shape that is relatively close to a sphere or cylinder, such as silicon spheres, silica particles, and carbon nanotubes. Is very difficult to grasp. The reason will be described below.
As shown in FIG. 13C, when the minute object M is grasped by the pair of grasping portions G and G, the force F applied to the minute object M from each grasping surface S of the pair of grasping portions G and G is on the same straight line. In other words, in other words, when the gripping surfaces S of the pair of gripping portions G and G are not parallel to each other, a force F1 in the direction of the gripping surface S is generated. If this force F1 becomes larger than the frictional force generated between the gripping surface S of the gripping part G and the minute object M, the minute object M slides on the gripping surface S of the gripping part G and moves. When the minute object M is spherical, the contact area between the gripping surface S and the minute object M is very small and the frictional force is small. Then, if the gripping surfaces S are not parallel to each other, the minute object M slides and moves on the gripping surface S of the gripper G, so that the minute object such as a sphere is very difficult to grip.
Therefore, in order to securely hold a spherical or cylindrical minute object, a gripper is required in which the gripping surfaces of the gripping parts are parallel to each other when the minute object and the gripping part are in contact with each other.

  However, in the case of the grippers 100 and 110 described above, since the arm 105 swings, it is almost impossible to make the gripping surfaces S of the gripping portion 106 parallel to each other when the minute object M is gripped. In order to bring the minute object and the gripping part into contact with the gripping surfaces of the gripping parts in parallel, it is the most reliable method to move the arms while keeping the gripping faces of the gripping parts of the pair of arms parallel to each other. There is a need for a gripper having such a configuration.

JP-A-8-52673 Japanese Patent No. 2739028

  SUMMARY OF THE INVENTION In view of the above circumstances, the present invention has an object to provide a gripper that can accurately move an arm without enlarging a drive mechanism and can reliably grip even a micro object of micro order. And

A gripper according to a first aspect of the present invention includes a pair of arms provided with a gripping part that supports an object in between and arranged so that the axes are located on the same plane , and a drive for approaching and separating the gripping part of the pair of arms. A gripper provided with a mechanism, wherein the gripping portions of the pair of arms each have gripping surfaces that are parallel to each other, and the drive mechanism keeps the gripping surfaces parallel to each other. The arm holding portion is moved close to and separated from each other, and includes a pair of arm drive portions that operate the pair of arms, and each arm drive portion includes a movable member attached to the arm , and the movable member. a holding member for movably held along the normal direction of the gripping surface provided on the grip portion of the arm, the law of the gripping surface is provided for the movable member, the grip portion of the arm Along the line direction Te, consists of a power source for applying a force in the direction in which the arm is close to the other arm, the holding member is a beam member having an axis perpendicular to the normal direction of the gripping surface of the arm, The movable member is a shaft-like member having an axis parallel to the normal direction of the gripping surface of the arm , and a central axis is provided so as to be located on the same plane as the axis of the arm. The source includes a pair of electrode portions each having a comb-shaped movable electrode provided on the movable member and a comb-shaped fixed electrode whose movement is fixed to the base of the gripper. It is arranged so as to be symmetrical and located on the same plane with respect to the axis of the movable member ,
The pair of arms and the movable member, the holding member, and the pair of electrode portions in the pair of arm driving units are all disposed on the same plane .
The gripper according to a second aspect of the present invention is the gripper according to the first aspect, wherein the electrode portion includes a movable electrode side shaft portion in which the movable electrode has an axis parallel to the holding member, and the fixed electrode side of the movable electrode side shaft portion. A comb-like electrode having a plurality of movable teeth provided on a side surface of the movable electrode, wherein the fixed electrode is parallel to an axial direction of the movable electrode side shaft portion and flush with an axis of the movable electrode side shaft portion A comb-like electrode comprising: a fixed electrode side shaft portion having a shaft disposed on the movable electrode; and a plurality of fixed teeth provided on a side surface of the fixed electrode side shaft portion on the movable electrode side. The plurality of movable teeth are arranged between adjacent fixed teeth of the fixed electrode.
A gripper according to a third invention is characterized in that, in the first invention, the pair of arms, the movable member of the arm drive unit, the holding member, and the electrode part are all formed from a single plate-like member. .
The gripper according to a fourth aspect is characterized in that, in the first aspect, the one arm and the movable member of the arm drive unit are connected via an insulating material.

According to the first invention, an object can be gripped in a state where the gripping surfaces of the gripping portions of the pair of arms are kept parallel to each other. Then, when the object is gripped, a force having a component in a direction parallel to the gripping surface is not generated between the object and the gripping surface, so that even if the object has a spherical shape, the gripping is surely performed. Can do. In addition, since the drive mechanism moves the gripping parts closer to each other while keeping the gripping surfaces parallel, regardless of the size of the object to be gripped, always hold the object with the gripping surfaces kept parallel. Can do. In addition, since the holding member is a beam-like member, if a force is applied to one movable member from the power source, the holding member bends to the other arm side, so that the movable member is moved toward the other arm. be able to. Then, since one arm is biased toward the other arm, one arm can be moved toward the other arm, and the grip portion of one arm is brought close to the grip portion of the other arm. be able to. Then, if there are no forces from the power source, by the restoring force of the holding member, the movable member Before moving an arm in the opposite direction. Then, since one arm is urged in a direction away from the other arm and moved away from the other arm, the grip portion of one arm can be separated from the grip portion of the other arm. Then, the holding member, because they have an axis perpendicular to the normal direction of the gripping surface of A over arm, the movement of the movable member is constrained in the direction normal to the gripping plane of A over arm. Therefore, even if one arm approaches and separates from the other arm, the gripping surfaces can always be kept parallel. And even if the axial force of the holding member is generated from one electrode portion with respect to the movable member, the force can be canceled by the other electrode portion. that is, it is possible to close Ki out applying a force only in the normal direction of the gripping surface of one arm, one arm remains more reliably gripping faces are kept parallel to the other arms. Further, since the pair of arms can be moved, the range of the distance that can be taken by the gripping portions of the pair of arms can be widened. And since the range of the size of the minute object which can be grasped can be widened, the versatility of the gripper can be enhanced. Since the pair of arms, the movable member of the pair of arm driving units, the holding member, and the pair of electrode units are all disposed on the same plane, the pair of arms and the pair of arm driving units are movable. All members and the like can be reliably moved on the same plane. Therefore, when the gripping portions of the pair of arms approach and separate from each other, it is possible to suppress the displacement of the gripping portions in the thickness direction, and it is possible to grip a minute object between the gripping portions more reliably.
According to the second aspect of the invention, if a voltage is applied between the fixed electrode and the movable electrode, an electrostatic force attracting each other is generated between the two electrodes. This electrostatic force causes the movable electrode to be fixed to the movable member. It is possible to apply a biasing force in the direction of moving toward the side, that is, the direction toward one of the arms. In addition, each electrode is provided with a plurality of teeth, and the teeth of the fixed electrode and the movable electrode are alternately arranged along the axial direction of the holding member. Then, even if the distance between adjacent teeth of the fixed electrode and the movable electrode is shortened, the moving distance of the movable electrode can be increased. Therefore, the electrostatic force generated between both electrodes can be increased to increase the urging force applied to the movable member, and the moving distance of the movable member can be increased. Further, since the movable teeth are located between the adjacent fixed teeth, and only the electrostatic force in the axial direction of the movable member acts on the movable teeth, the movable member can be biased only in the axial direction .
According to the third aspect , all the members can be reliably arranged on the same plane, and all the arms, movable members, and the like can be reliably moved on the same plane. Therefore, since it is possible to suppress the displacement of the grip portion in the thickness direction when the grip portion approaches and separates, a minute object can be gripped between the grip portions more reliably.
According to the fourth invention , since it is possible to prevent the voltage applied to the electrodes from being applied to the pair of arms, even a minute object that must be operated in an insulated state can be operated.

  The gripper of the present invention is used for gripping minute objects such as micro-order silicon samples and biological samples, and is difficult to sandwich and hold, for example, a curved surface whose outer shape is cylindrical or spherical. It is characterized in that it is configured so that even a minute object having a mark can be reliably gripped.

Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic plan view of a gripper 1 of the present embodiment. FIG. 2 is a schematic cross-sectional view of the gripper 1 of the present embodiment at each position in FIG. FIG. 3 is a schematic enlarged view of a main part of the gripper 1 of the present embodiment.

  In FIG. 1, the code | symbol 10 has shown a pair of arm which hold | grips an object. The pair of arms 10 and 10 are shaft-like members having substantially the same shape, and are arranged in a state separated by a predetermined interval (for example, 10 μm) so that the axial directions thereof are parallel to each other. . Each arm 10 does not bend even when holding its own weight or the above-described minute object, or the strength is such that the amount of bending does not affect the gripping of the minute object even if the bending occurs. Is formed. For example, when the material is a silicon single crystal and the length of the arm 10 is 3 mm, the thickness is about 10 to 40 μm and the width is about 10 to 50 μm. It should be noted that the dimensions of the arm 10 are not limited to the above dimensions, and it is needless to say that the dimensions of the arm 10 are appropriately designed according to the material of the arm 10 so that the arm 10 does not bend.

  At the tip of each arm 10, a grip portion 11 having a thickness thinner than other portions of the arm 10 is formed. In the gripping portions 11 of the pair of arms 10 and 10, gripping surfaces 11 s that are parallel to each other in a state where the pair of arms 10 and 10 are separated from each other by a predetermined distance are formed on the surfaces facing each other. .

On the other hand, the base end portions of the pair of arms 10 and 10 are respectively held by the pair of arm drive portions 21 and 21 of the drive mechanism 20, and are attached to the base 2 via the pair of arm drive portions 21 and 21. It has been.
The pair of arm drive units 21, 21 is a pair of arms 10, 10, in other words, a pair of arms 10, 10, with the gripping surfaces 11 s of the gripping portions 11 of the pair of arms 10, 10 kept parallel to each other. The grip portions 11 are moved closer to and away from each other, details of which will be described later.

Since the gripper 1 of the present embodiment has the above-described configuration, a minute object is disposed between the gripping surfaces 11s of the gripping portions 11 of the pair of arms 10 and 10, and the pair of the drive mechanism 20 is in that state. If the arm driving units 21 and 21 are operated, the gripping portions 11 can be brought close to each other while the gripping surfaces 11s are kept parallel to each other. For this reason, since the gripping surface 11s of the gripping part 11 can be brought into contact with the minute object while the gripping surfaces 11s are kept parallel to each other, the minute object is moved from the gripping surface 11s of each gripping part 11 to the gripping surface 11s. It can be gripped in a state where only a force in a direction perpendicular to the direction is applied. Then, when the minute object is spherical or cylindrical, any force applied from the grasping surface 11s of each grasping portion 11 can be positioned on a line that is perpendicular to the grasping surface 11s and passes through the center of the minute object. Then, since a force having a component in a direction parallel to the gripping surface 11s is not generated between the minute object and the gripping surface 11s, even a spherical or cylindrical minute object can be reliably gripped. .
In addition, since the pair of arms 10 and 10 approach each other while the gripping surfaces 11s of the gripping part 11 are always kept parallel, the gripping surfaces 11s are always parallel regardless of the size of the object to be gripped. The object can be gripped in a state where it is kept in the position.

  In addition, each arm 10 is formed with a strength that does not bend due to its own weight or the like, or even if a bend occurs, the amount of bend does not affect the gripping of a minute object. It is possible to prevent the minute object from being in a state where it cannot be gripped due to the displacement of the positions of the gripping surfaces 11s.

Furthermore, since the pair of arms 10 and 10 are respectively attached to the arm drive unit 21, the range in which the pair of arms 10 and 10 can move can be made longer than when only one arm 10 is moved. The range of the distance that the gripping portions 11 of the pair of arms 10 and 10 can take can be widened. Then, since the range of the size of the minute object that can be gripped can be widened, the versatility of the gripper 1 can be enhanced.
One arm 10 may be fixed to the base 2 so as not to move. In this case, the drive mechanism 20 only needs to include the arm drive unit 21 that drives the other arm 10.

  Next, the pair of arm drive units 21 and 21 of the drive mechanism 20 will be described. Since the pair of arm drive units 21 and 21 have substantially the same configuration, the left arm drive unit 21 will be described below as a representative.

As shown in FIGS. 1 to 3, one end of the movable member 22 of the arm drive unit 21 is attached to the base end of the arm 10. The movable member 22 is a shaft-shaped member, and is arranged so that the axial direction thereof is parallel to the normal direction of the gripping surface 11 s of the gripping portion 11 of the arm 10 and is positioned in a plane including the axis of the arm 10. It is installed.
The movable member 22 may not necessarily be positioned in a plane including the axis of the arm 10 as long as the axial direction thereof is parallel to the normal direction of the gripping surface 11s of the gripping portion 11 of the arm 10. If the arm 10 is positioned in a plane including the axis of the arm 10, the arm 10 can be translated more reliably.
Furthermore, the arm 10 and the movable member 22 may not be directly attached, and may be attached via the insulating member 22a. In this case, as will be described later, even if the power source is the electrode unit 25, it is possible to prevent the voltage applied to the electrode unit 25 from being applied to the arm 10, so that it is a minute object that must be operated in an insulated state. Even if it exists, it becomes possible to operate.

1 to 3, reference numeral 23 denotes a pair of holding members that hold the movable member 22 movably with respect to the base 2. The pair of holding members 23 and 23 are beam-like members parallel to each other, and both end portions in the axial direction of the movable member 22 are attached to the center portions in the axial direction of the pair of holding members 23 and 23. Yes.
The pair of holding members 23, 23 are arranged so that the axial direction thereof is perpendicular to the normal line of the gripping surface 11 s of the gripping portion 11 of the arm 10, and are attached to the base 2 only at both ends in the axial direction. It has been. In addition, the pair of holding portions 23 and 23 are located on the same plane, and are arranged so that the plane is a plane including the axis of the arm 10 and the normal line of the gripping surface 11s of the gripping portion 11 of the arm 10. It is installed.
For this reason, when a force is applied to the movable member 22 in the axial direction, the pair of holding portions 23 and 23 bend along that direction, in other words, along the normal direction of the gripping surface 11s of the gripping portion 11 of the arm 10. Therefore, the movable member 22 can be moved only in the axial direction.

  The pair of holding members 23 and 23 must support the weight of the movable member 22, the arm 10, and the weight of the minute object supported by the arm 10, and move the movable member 22 only in the axial direction. In addition, in order to prevent the positions of the gripping surfaces 11s in the thickness direction of the arm 10 from shifting, the bending does not occur in the direction perpendicular to the axial direction of the movable member 22 even when the weight is applied, or the bending Even if this occurs, the amount of bending is such that it does not affect the gripping of the minute object. For example, if the material of the holding member 23 is a silicon single crystal and the length is 1.5 mm, the thickness is about 10 to 40 μm and the width is about 10 to 20 μm. Needless to say, the dimensions of the holding member 23 are not limited to the above-described dimensions, and are appropriately designed so that the holding member 23 does not bend according to the material of the holding member 23.

Note that the plane on which the pair of holding portions 23 and 23 are arranged may not be a plane including the axis of the arm 10 and the normal line of the gripping surface 11s of the gripping portion 11 of the arm 10 as described above. Any plane that is parallel to the normal of the gripping surface 11s of the part 11 may be used. That is, it is only necessary that the pair of holding members 23 and 23 be arranged so as to be able to bend along the normal direction of the gripping surface 11s.
Furthermore, the movable member 22 can be held such that its axial direction is parallel to the normal direction of the gripping surface 11s of the gripping portion 11 of the arm 10 and can only move in the axial direction. For example, the attachment position of the both ends of the movable member 22 with respect to the pair of holding members 23, 23 is not limited to the central portion in the axial direction of the pair of holding members 23, 23. For example, if the axial diameter and shape of the holding member 23 are changed along the axial direction (see FIG. 4), the end of the movable member 22 is placed at a position biased to any axial end of the holding member 23. Even when attached, the movable member 22 can be held such that its axial direction is parallel to the normal direction of the gripping surface 11s of the gripping portion 11 of the arm 10 and can only move in the axial direction.
Furthermore, the holding member 23 may be one as long as it can move the movable member 22 only in the axial direction, and if the bending does not occur in a direction orthogonal to the axial direction of the movable member 22. A cantilever structure may be used.

  As shown in FIGS. 1 to 3, between the pair of holding members 23, 23, the base 2 and the movable member 22 are positioned symmetrically and on the same plane with respect to the axis of the movable member 22. A pair of electrode portions 25 are provided. Each electrode portion 25 includes a fixed electrode 26 fixed to the base 2 and a movable electrode 27 attached to the movable member 22, and the movable electrode 27 sandwiches the fixed electrode 26 between the arm 10. Arranged in position. In other words, the movable electrode 27 is disposed at a position sandwiching the fixed electrode 26 with the holding member 23 located on the arm 10 side. Each electrode is connected to a power source (not shown) via a wiring L.

The fixed electrode 26 has one end attached to the base 2 and a fixed electrode side shaft portion 26a having an axis parallel to the holding member 26, and a plurality of fixed electrodes 26 provided on the side surface of the fixed electrode side shaft portion 26a on the movable electrode 27 side. A comb-like electrode having fixed teeth 26b. The plurality of fixed teeth 26 b of the fixed electrode 26 are arranged so that the axial direction thereof is parallel to the axial direction of the movable member 22.
The movable electrode 27 is a comb including a movable electrode side shaft portion 27a, one end of which is fixed to the movable member 22, and a plurality of movable teeth 27b provided on a side surface of the movable electrode side shaft portion 27a on the fixed electrode 26 side. Electrode. The plurality of movable teeth 27b of the movable electrode 27 are also arranged so that the axial direction thereof is parallel to the axial direction of the movable member 22, like the fixed teeth 26b. The movable electrode 27 is disposed such that the plurality of movable teeth 27b are positioned between the adjacent fixed teeth 26b of the fixed electrode 26.

For this reason, when a voltage is applied between the fixed electrode 26 and the movable electrode 27, an electrostatic force attracting each other is generated between the two electrodes. Then, the fixed electrode 26 is fixed to the base 2, and the movable electrode 27 is disposed so as to sandwich the fixed electrode 26 between the holding member 23 positioned on the arm 10 side. Thus, the movable electrode 27 is biased to move toward the fixed electrode 26. That is, since the movable electrode 27 is biased so as to move toward the arm 10, a biasing force in the direction toward the arm 10 is applied to the movable member 22 to which one end of the movable electrode 27 is attached.
In addition, the fixed electrode 26 and the movable electrode 27 are both comb electrodes, and the plurality of movable teeth 27b are disposed between the fixed teeth 26b adjacent to the fixed electrode 26. In other words, since the teeth of the fixed electrode 26 and the movable electrode 27 are arranged alternately along the axial direction of the holding member 23, the moving direction of the movable electrode 27 is parallel to the axial direction of the movable tooth 27b. Become. For this reason, if the distance L1 between the side surface of the fixed electrode 26 and the movable tooth 27b of the movable electrode 27 in a state where no voltage is applied is increased, the distance W1 between the movable tooth 27b and the adjacent fixed tooth 26b is decreased. Even so, the moving distance of the movable electrode 27 can be increased. Therefore, by shortening the distance W1 between the movable tooth 27b and the adjacent fixed tooth 26b, the electrostatic force generated between the two electrodes can be increased to increase the biasing force applied to the movable member 22, and the movable electrode The moving distance of 27 can be increased.
Furthermore, since the movable tooth 27b is located between a pair of adjacent fixed teeth 26b, the electrostatic force in the direction orthogonal to the axial direction of the movable tooth 27b is canceled out. Then, since only the electrostatic force in the axial direction acts on the movable tooth 27b, the movable electrode 27 can be moved only along the axial direction of the movable tooth 27b. Therefore, since the axial direction of the movable tooth 27b is parallel to the axial direction of the movable member 22, the movable member 22 can be urged only in the axial direction.
Said electrode part 25 is a power source said to a claim.

The electrode portion 25 may be provided with a plurality of pairs of the fixed electrode 26 and the movable electrode 27 as described above along the axial direction of the movable member 22. In this case, the urging force applied to the movable member 22 is further increased. Can be bigger.
And in the gripper 1 of this embodiment, by comprising the electrode part 25 as mentioned above, the urging | biasing force added to the movable member 22 can be enlarged while the electrostatic force which generate | occur | produces between both electrodes can be enlarged. Then, the arm 10 and the holding member 23 are formed so as not to bend, and even if the weight of the arm 10 or the like becomes heavy or the strength of the holding member 23 increases, the holding member 23 is bent as described later. Thus, an urging force sufficient to move the movable member 22 and the arm 10 can be applied to the movable member 22.

  The power source is not limited to the so-called electrostatic actuator using the electrostatic force as described above, but may be a piezoelectric actuator or an electromagnetic actuator, and is configured to be able to apply force only in the axial direction of the movable member 22. It only has to be.

Since the gripper 1 of the present embodiment has the configuration as described above, it can operate as follows to release and hold a minute object.
When gripping a minute object, a voltage is applied between the fixed electrode 26 and the movable electrode 27 of the arm drive unit 20. Then, the movable member 22 is biased along the axial direction toward the arm 10 to which one end thereof is attached, and the pair of holding members 23 are also orthogonal to the axial direction via the movable member 22. It is energized from the direction. Since the holding member 23 is a beam-like member, it bends along the normal direction of the gripping surface 11s of the gripping portion 11 of the arm 10 according to the urging force applied via the movable member 22, so that the movable member 22 It can be moved toward the arm 10 along the axial direction. Then, since the arm 10 can be moved together with the movable member 22, one arm 10 can be moved toward the other arm 10, and the grip portion 11 of one arm 10 can be moved to the grip portion of the other arm 10. 11 can be approached.
Moreover, the movable member 22 is disposed so that its axial direction is parallel to the normal direction of the gripping surface 11 s of the gripping portion 11 of the arm 10 and is positioned in a plane including the axis of the arm 10. The grip surface 11s of the grip portion 11 of the arm 10 moves along the normal direction. Therefore, the gripping surfaces 11s of the pair of arms 10 can be brought close to each other while being kept parallel to each other.

When the pair of arm driving units 20 are operated to bring the gripping units 11 of one arm 10 closer to each other, the pair of arms is provided if the axial directions of the movable members 22 of the pair of arm driving units 20 are parallel to each other. The ten gripping surfaces 11s can be brought close to each other while being kept parallel to each other. This requirement is satisfied if the arm drive unit 20 is configured as described above. However, the gripping surfaces 11s of the pair of arms 10 are brought closer to each other while being held in parallel with each other, and the thickness of the gripping unit 11 is increased. In order to more reliably suppress the deviation of the direction, the holding members 23 of the pair of arm drive units 20 are arranged so that the axial directions thereof are parallel, or the axial directions of the movable members 22 are arranged coaxially. Just do it.
If the pair of arms 10 and 10, the movable member 22 of the pair of arm driving units 20, the pair of holding members 23 and 23, and the electrode unit 25 are all disposed on the same plane, the pair of arms 10, 10 and the movable member 22 of the pair of arm drive units 20 can all be reliably moved on the same plane. Therefore, when the gripping portions 11 of the pair of arms 10, 10 approach and separate from each other, It is possible to more reliably suppress the deviation in the thickness direction of the portion 11, and it is possible to more securely hold the minute object between the holding portions.

  Further, if the application of voltage is stopped, the force for urging the holding member 23 disappears, so that the holding member 23 returns to its original state by its own restoring force, and the movable member 22 is restored as the holding member 23 is returned. Is moved in the opposite direction to that when the voltage is applied, that is, in the direction away from the arm 10. Then, since one arm 10 is moved so as to be separated from the other arm 10 together with the movable member 23, the grip portion 11 of one arm 10 can be separated from the grip portion 11 of the other arm 10.

  In addition, as shown in FIG. 1, if a pair of electrode portions 25 are provided so as to be symmetric with respect to the axis of the movable member 22, the holding member 23 can be moved from one electrode portion 25 to the movable member 22. Even if an axial force is generated, the other electrode portion 25 can cancel the force. Therefore, since the force can be applied only to the movable member 22 in the axial direction, that is, in the normal direction of the gripping surface 11s of the gripping portion 11 of the arm 10, the gripping surfaces 11s are more reliably kept parallel to each other. A pair of arms 10 and 10 can be made to approach as it is.

  If the pair of arms 10 and 10, the movable member 22 of the pair of arm driving units 20, the pair of holding members 23 and 23, and the electrode unit 25 are all disposed on the same plane, the pair The arm members 10 and 10 and the movable members 22 of the pair of arm drive units 20 can all be reliably moved on the same plane, so when the gripping portions 11 of the pair of arms 10 and 10 approach and separate from each other, It is possible to suppress the displacement of the grip portion 11 in the thickness direction, and it is possible to more securely grip a minute object between the grip portions.

  The gripper 1 of the present embodiment may be manufactured by combining a plurality of shaft-like members and the like that are formed separately, but if manufactured as follows, the parallelism and arrangement of each member are very accurate. This is suitable because it can be matched well.

5-10 is the figure which showed the manufacturing process of the gripper 1 of this embodiment. 11 and 12 are flowcharts of the manufacturing process of the gripper 1 of the present embodiment.
First, the silicon substrate 50 that is the basic material of the gripper 1 of the present embodiment will be described.
In FIG. 5A, reference numeral 50 denotes a silicon substrate that is a basic material of the gripper 1 of the present embodiment. The silicon substrate 50 has a base layer 51, an insulating layer 52, and a silicon layer 53 laminated in order.

The material of the base layer 51 of the silicon substrate 50 is, for example, silicon such as Si (100) substrate, Si (111) substrate, Si (110) substrate, polysilicon, etc., and the thickness thereof is formed to 100 to 1000 μm. It is a thing.
The material of the base layer 51 is not limited to silicon, and may be glass or the like, and is not particularly limited as long as the material has a property that it can be processed by dry anisotropic etching or wet anisotropic etching. The thickness of the base layer 51 is not limited to the above range, and may be appropriately designed according to the use of the gripper 1. For example, if it is the gripper 1 used for operation of micro objects, such as a silicon sample and a biological sample, what is necessary is just about 50-500 micrometers.

The material of the insulating layer 52 of the silicon substrate 50 is silicon oxide, and the thickness thereof is formed to 0.1 to 5 μm.
The material of the insulating layer 52 is not limited to silicon oxide, and may be formed of a material that can electrically insulate between the base layer 51 and the silicon layer 53.

The material of the silicon layer 53 of the silicon substrate 50 is silicon, and the thickness thereof is about 5 to 50 μm. Since this silicon layer 53 becomes the arm 10 of the gripper 1, etc., for example, if the gripper 1 is used for operation of a silicon sample, a biological sample or the like, about 10 to 40 μm is preferable.
Although there is no particular limitation on the properties of silicon used as the material of the silicon layer 53, the elasticity of the arm 10 of the gripper 1 and the like changes depending on the surface orientation of the surface and the like. Silicon may be selected.

  As the silicon substrate 50 as described above, for example, a so-called SOI substrate (Silicon On Insulator) in which a silicon oxide layer is formed as an intermediate layer between a pair of upper and lower silicon layers is suitable. It may be a substrate having a single crystal silicon layer, or a substrate having an SOI layer on an amorphous or polysilicon substrate. As long as the silicon layer 53 is electrically insulated from the lower layer than the insulating layer 52 by the insulating layer 52, the silicon substrate 50 is not limited to the three-layer structure, and may be four or more layers.

Next, a method for manufacturing the gripper 1 from the silicon substrate 50 will be described.
As shown in FIGS. 5 and 11, a mask film 54 made of aluminum, silicon nitride, or the like is first formed on the surface of the silicon layer 53 of the silicon substrate 50 by a known film formation method such as sputtering or vacuum evaporation. Is formed (S11).
Next, as shown in FIG. 5B, a resist film 55 for photolithography is formed on the surface of the mask film 54 by a spin coater or the like (S12).

Next, although not shown, a photolithographic mask having the shape of the gripper 1 to be manufactured, that is, the shape of the pair of arms 10 and the pair of arm driving portions 21 (see FIG. 1), is applied to the surface of the resist film 55. Put it on. In order to make this photolithography mask, the outline of the mask is drawn with CAD software, and this figure is drawn on the mask sheet with a mask making apparatus.
Then, when the photolithographic apparatus is irradiated with ultraviolet rays with the photolithographic mask placed on the surface of the resist film 55 (S13), the figure on the photolithographic mask is transferred to the surface of the resist film 55, and the mask A resist 56 having substantially the same shape as the gripper 1 to be manufactured is formed on the surface of the film 54, and the mask film 54 is exposed at a portion not covered with the resist 56 (FIG. 6A).
Next, if the mask film 54 in a portion not covered with the resist 56 is etched with, for example, a mixed acid solution (S14), the silicon layer 53 is exposed (FIG. 6B).

Next, anisotropic etching is performed on the exposed silicon layer 53 in a direction perpendicular to the surface of the silicon layer 53 by ICP-RIE (Inductively Coupled Plasma Reactive Ion Etching) called deep RIE (S15). Then, the insulating layer 52 is exposed.
For example, when the resist 56 and the mask film 54 are removed with a resist stripping solution such as sulfuric acid / hydrogen peroxide mixed solution (S16), the silicon layer 53 processed into the shape of the gripper 1 is formed on the surface of the insulating layer 52. Exposed (FIG. 7A).

  Next, a resist film 57 is formed on the surface of the silicon layer 53 and the insulating layer 52 processed into the shape of the gripper 1 by a spin coater or the like (S17, FIG. 7B). Then, when the resist film 57 is irradiated with ultraviolet rays by the photolithography apparatus on the processed silicon layer 53 other than the tip of the arm 10 of the gripper 1, that is, the portion covering the position corresponding to the grip portion 11. (S18) The portion of the resist film 57 covering the position corresponding to the grip portion 11 is removed, and the portion corresponding to the grip portion 11 in the processed silicon layer 53 is exposed (FIG. 8A). In this state, if the portion corresponding to the gripping portion 11 is processed into a shape or size suitable for the target to be gripped by ICP-RIE or the like, the processing of the silicon layer 53 is completed.

  As shown in FIG. 8B and FIG. 12, when the processing of the silicon layer 53 is completed, the silicon substrate 50 is inverted, and the back surface of the silicon substrate 50, in other words, the back surface of the base layer 51 is directed to the top surface. A mask film 61 made of aluminum, silicon nitride or the like is formed by a known film formation method such as sputtering or vacuum deposition (S21), and a photolithography resist film 62 is formed on the surface of the mask film 61 by a spin coater or the like. Is formed (S22).

  Next, although not shown, a photolithographic mask having the shape of the base 2 of the gripper 1 to be manufactured and the shape of the insulating member 22a (see FIG. 1) is placed on the surface of the resist film 62, and ultraviolet rays are emitted by a photolithographic apparatus. Irradiate (S23). Then, the figure of the mask for photolithography is transferred to the resist film 62, and a resist 63 having the shape of the base 2 and the shape of the insulating member 22 a is formed on the surface of the resist film 61 and covered with the resist 63. The mask film 61 is exposed in the portion that is not present. Then, if the portion of the mask film 61 not covered with the resist 63 is etched with, for example, a mixed acid solution (S24), the back surface of the base layer 51 is exposed (FIG. 9A).

Next, anisotropic etching is performed on the exposed base layer 51 in a direction perpendicular to the back surface of the base layer 51 by ICP-RIE or the like (S25), and the back surface of the insulating layer 52 is exposed.
Then, for example, the resist film 57, the mask film 61, and the resist 63 are all removed with a resist stripping solution such as a sulfuric acid / hydrogen peroxide mixed solution (S26), and the base layer 51 and the silicon layer 53 are buffered with hydrogen fluoride aqueous solution. The insulating layer 52 other than the portion sandwiched between the layers is removed (S27, FIG. 9B, FIG. 10A).

  Finally, in the processed silicon layer 53, if a conductor film 64 such as gold or aluminum is formed on the surface corresponding to the arm 10 and the arm drive unit 21 (S28), the gripper 1 of this embodiment is manufactured. can do.

  If the gripper 1 of this embodiment is manufactured by the method as described above, the pair of arms 10, the movable member 22 of the arm driving unit 21, the holding member 23, and the electrode unit 25 are all formed by a single silicon layer 53. Therefore, the accuracy in the thickness direction of each member can be made very high. In addition, since the relative positions of the members, particularly the relative positions of the fixed electrode 26 and the movable electrode 27 of the electrode portion 25, are very high, the gripping surfaces 11s of the gripping portions 11 of the pair of arms 10 Can be moved closer to and away from each other while keeping them in parallel.

  As shown in FIG. 10, when the silicon substrate 50 is processed, if the protective portion 70 is also formed at the same time, the portion corresponding to the protective portion 70 corresponds to the arm 10 in the silicon layer 53 during processing. This is preferable because it can prevent the portion to be damaged from being damaged.

  The gripper of the present invention is suitable for an apparatus for manipulating fine dust generated during a semiconductor / display processing process or a biological sample such as a cell, and in particular, relatively, like silicon spheres, silica fine particles, carbon nanotubes, etc. It is suitable as a device for manipulating a minute object that has a shape similar to a spherical shape or a cylindrical shape and is very difficult to grasp.

It is a schematic plan view of the gripper 1 of this embodiment. It is a schematic sectional drawing of the gripper 1 of this embodiment in each position of FIG. It is a principal part schematic enlarged view of the gripper 1 of this embodiment. It is a schematic plan view of the gripper 1 of another embodiment. It is the figure which showed the manufacturing process of the gripper 1 of this embodiment. It is the figure which showed the manufacturing process of the gripper 1 of this embodiment. It is the figure which showed the manufacturing process of the gripper 1 of this embodiment. It is the figure which showed the manufacturing process of the gripper 1 of this embodiment. It is the figure which showed the manufacturing process of the gripper 1 of this embodiment. It is the figure which showed the manufacturing process of the gripper 1 of this embodiment. It is a flowchart of the manufacturing process of the gripper 1 of this embodiment. It is a flowchart of the manufacturing process of the gripper 1 of this embodiment. (A) is a diagram showing an example of a gripper 100 driven by a thermal expansion actuator, (B) is a diagram showing an example of a gripper 110 driven by an electrostatic actuator, and (C) is a diagram showing a conventional one. It is explanatory drawing of the state which hold | gripped the micro object M with the gripper.

DESCRIPTION OF SYMBOLS 1 Gripper 2 Base 10 Arm 11 Grip part 11s Grip surface 20 Drive mechanism 21 Arm drive part 22 Movable member 23 Holding member 25 Electrode part 26 Fixed electrode 26a Fixed electrode side axial part 26b Fixed tooth 27 Movable electrode 27a Movable electrode side axial part Part 27b Movable teeth

Claims (4)

A gripper provided with a gripping part for supporting an object in between and arranged so that axes are located on the same plane , and a drive mechanism for approaching and separating the gripping part of the pair of arms. And
The gripping portions of the pair of arms respectively include opposing parallel gripping surfaces,
The drive mechanism is
While holding the gripping surfaces in parallel, the gripping portions of the pair of arms are approached and separated ,
A pair of arm drive units for operating each of the pair of arms;
Each arm drive unit
A movable member attached to the arm ;
A holding member that holds the movable member movably along a normal direction of a gripping surface provided in a gripping portion of the arm ;
Wherein the movable member, the along the normal direction of the gripping surface provided on the grip portion of the arm, consists of a power source for applying a force in the direction in which the arm is close to the other arm,
The holding member is
A beam-like member having an axis perpendicular to the normal direction of the gripping surface of the arm ;
The movable member is
An axial member having an axis parallel to the normal direction of the gripping surface of the arm ;
The central axis is provided so as to be on the same plane as the axis of the arm ,
The power source is
A pair of electrode portions having a comb-shaped movable electrode provided on the movable member and a comb-shaped fixed electrode whose movement is fixed to the base of the gripper;
The pair of electrode portions are
It is arranged so as to be symmetrical and located on the same plane with respect to the axis of the movable member ,
The gripper , wherein the pair of arms and the movable member, the holding member, and the pair of electrode portions in the pair of arm driving units are all disposed on the same plane . The electrode part is
The movable electrode is
A comb-like electrode comprising a movable electrode side shaft portion having an axis parallel to the holding member, and a plurality of movable teeth provided on a side surface of the movable electrode side shaft portion on the fixed electrode side,
The fixed electrode is
The fixed electrode side shaft portion having an axis parallel to the axial direction of the movable electrode side shaft portion and disposed on the same plane as the axis of the movable electrode side shaft portion, and the movable electrode in the fixed electrode side shaft portion A comb-like electrode provided with a plurality of fixed teeth provided on the side surface;
The gripper according to claim 1, wherein a plurality of movable teeth of the movable electrode are disposed between adjacent fixed teeth of the fixed electrode. The gripper according to claim 1, wherein the pair of arms, the movable member of the arm driving unit, the holding member, and the electrode unit are all formed from a single plate-like member. The gripper according to claim 1, wherein the one arm and the movable member of the arm driving unit are connected via an insulating material.