Multiple degrees of freedom specimen holder
Technical field
The present invention relates to the specimen holders used under electron microscope, transmission electron microscope.
Background technique
Home position observation technology has long history in transmission electron microscopy research.It is various by applying on sample
Physical action observes the microstructure of material and the variation of chemical state using transmission electron microscope (transmission electron microscope), can
With the performance of directly research material or device in actual use, have for the research of material property important
Practical significance.In-situ techniques its difficulty in transmission electron microscope is not only accurately to be applied to physical action on sample, together
When also to meet a series of exacting terms, for example to maintain the ultra-high vacuum of Electronic Speculum system, guarantee high steady of sample stage
Fixed degree, and imaging optical path cannot be interfered, total must be compact to be suitable for the narrow sample room etc. of transmission electron microscope.Therefore,
The difficult point major embodiment of electron microscopy in situ is in situ in the research and production of specimen holder.
Article " the Compact design of a that Sweden Svensson, K. et al. were delivered in 2003
transmission electron microscope-scanning tunneling microscope holder with
Three-dimensional coarse motion " a kind of three-dimensional piezoelectric probe is disclosed, this three-dimensional piezoelectric probe is transmission
A part of electronic microscope sample rod, piezo-electric probe include that a piezoelectric ceramic tube and a bead, bead are fixed on piezoelectric ceramic tube,
Equipped with the sample holder for catching bead by flexibility screw claw on bead, it is " slowly mobile, quick that piezoelectric ceramic tube controls bead work
Recall " slight amplitude (2.5 microns of piezoelectric ceramic tube axial direction or less, 30 microns of other two direction or less) circulation fortune
It is dynamic.Flexible screw claw firmly grasps bead by frictional force, and piezoelectric ceramic tube does shuttling movement, sample holder pass through flexible screw claw with it is small
Thus frictional force between ball generates that stroke is larger, the biggish Bit andits control of step-length (coarse adjustment) by continuous whipping.It makes pottery in conjunction with piezoelectricity
Smaller, the continuously adjustable Bit andits control (accurate adjustment) of the stroke that porcelain tube itself generates, can accumulate realization three in small space
The larger stroke (about 3mm) of freedom degree (axial translation one degree of freedom and around two freedom degrees of small ball rotation) it is accurate
Bit andits control.This three-dimensional piezoelectric probe oneself apply to the NanoEx 3D STM/EP system and NanoEx 3D of FEl company, the U.S.
Lndentor system is realized the STM in situ under transmission electron microscope, impression in situ and is electrically detected.
The shortcomings that this three-dimensional probe is: 1, flexible screw claw is easily-deformable, in order to keep its frictional force between bead,
It needs often to adjust the shape of flexible screw claw, but flexible screw claw has more, not can guarantee the consistency of every flexible screw claw, thus
Cause three-dimensional probe with the time and number used, precision is lower and lower.2, the length of flexible screw claw makes sample holder
There is gap between bead, when bead shuttling movement, makes sample holder along screw claw far from bead or close to bead, thus
Realize the axial displacement of sample, but sample holder is suspended on bead by flexibility screw claw, sample holder and sample thereon
Product can be to tenesmus by gravity, and position precision is not high.And the scope of sight in transmission electron microscope is nanometer and micron order, sample by
The position deviation of gravity likely results in sample and deviates the scope of sight of Electronic Speculum and can not observe;And position deviation is deposited
In the position and angle for causing to be difficult to be adjusted to sample to be suitble to observation.3, probe clamping device is along piezoelectric ceramic tube axial direction
When moving forward and backward, the relationship between the shape of flexible screw claw and above-mentioned frictional force is complicated, adjusts its shape and is difficult to ensure the friction
Power is suitable always.In addition probe clamping device is influenced by gravity, so that being easy to produce phase resultant motion in coarse adjustment, it is difficult to accurate
Control probe;Even since the Adjusting Shape of flexible screw claw is improper, bead cannot be caught, probe clamping device may be made to fall to
Inside equipment, equipment damage is caused.
Summary of the invention
The purpose of the present invention is to provide a kind of Three Degree Of Freedoms rotated with X-axis translation, Y-axis translation and Z axis, and in weight
The stable multiple degrees of freedom specimen holder of performance in multiple use.
Multiple degrees of freedom specimen holder, it is characterised in that: specimen holder is equipped with nanopositioner, and nanopositioner includes driving
Part, joint ball and casting die component, joint ball are fixed with actuator, and casting die component includes at least two casting dies and elastic connection group
Part, elastic connecting component connect adjacent casting die, and casting die component embraces joint ball, have pretightning force between casting die and joint ball.
For example piezoelectric ceramic tube is as actuator.
Casting die
As a preferred option, each casting die is respectively provided with recessed portion and interconnecting piece, and elastic connecting component is set to adjacent casting die
Between interconnecting piece, the recessed portion composition and the recess of joint ball cooperation of all casting dies.Recess is contacted with joint ball line or face connects
Touching or point contact;Elastic joint part makes have pretightning force between casting die and joint ball, when joint ball is static or actuator band
Joint ball when slowly moving, the stiction between joint ball and casting die keep the opposite shutdown ball of casting die static.When actuator band
Joint ball Rapid reset when, generate force of sliding friction between joint ball and casting die, joint ball reset casting die keep it is in situ, not with
It is resetted with joint ball.
Preferably, the hemispherical perhaps V-arrangement of recess or cone.
Preferably, casting die is the plate body of integral type, and depressed area is in the center of plate body.
Preferably, casting die is located at the outside of joint ball.When specimen holder is uprightly placed, nanopositioner upward, two sides be with
When specimen holder is uprightly placed, left-right and front-back be outside.Preferably, sample clamping part, all samples are respectively equipped on each casting die
Clamping part forms sample clamp.When all casting dies assemble in place, sample clamping part is combined into a sample clamp, sample clamp
For installing sample.When installation, joint ball is embraced from the two sides of joint ball with casting die, elastic connecting component provides casting die and joint
Pretightning force between ball.
As a preferred option, casting die includes the first casting die and the second casting die, the recessed portion of the first casting die and the second casting die
Recessed portion around be respectively uniformly distributed multiple installation positions, the corresponding elastic connecting component in each installation position, the first casting die
The installation bit-by-bit of installation position and the second casting die.In this way, elastic connecting component one end is installed on the installation position of the first casting die, it is another
End is installed on the installation position of the second casting die, and the elastic force of elastic connecting component is in a straight line, and does not generate torque.
Preferably, the first casting die and the second casting die are located at joint ball two sides.Alternatively, the first casting die is in upper, the second pressure
For part under, the recess of the second casting die is through-hole.The inner wall of through-hole is hemispherical, V-arrangement or cone etc..Preferably, the first casting die
Equipped with sample clamp.
As a preferred option, there is wearing layer on the recess surface of the first casting die.Preferably, the recess surface of the second casting die has
Wearing layer.
Elastic connecting component
As a preferred option, elastic connecting component is elastic (such as silicagel column, rubber column made of spring or elastic material
Deng), elastic connecting component one end is fixed with the first casting die, and the other end is fixed with the second casting die.After two casting dies embrace joint ball,
Elastic connecting component is in deformed state, and the restoring force of elastic connecting component provides two preloads between casting die and joint ball
Power.
Alternatively, elastic connecting component is made of screw rod and spring, spring pocket is loaded on screw rod, and spring is located at screw rod and the first pressure
Between part, the installation position of the second casting die is the screw hole with screw rod engagement.After screw rod is engaged with the installation position of the second casting die, at spring
In confined state, spring pushes away the first casting die to the second casting die, and spring provides the first casting die, the second casting die between joint ball
Pretightning force.
Preferably, the installation position of the first casting die is through-hole, and through-hole and screw clearance cooperate.Nothing is rubbed between through-hole and screw rod
It wipes, is conducive to the first casting die of promotion of spring.
Preferably, there is fixed part between the mounting hole or screw rod and the second casting die of the second casting die of screw rod stretching.For example,
Such as second casting die be installed in place after, screw rod and the second casting die are welded and fixed or are adhesively fixed.This is because joint ball
Shuttling movement and when the first casting die and the second casting die being driven to be displaced, the first casting die and the second casting die whipping will cause screw rod and second
Impact between casting die causes screw bolt loosening to be even detached from the second casting die;Screw bolt loosening will affect the accurate control of position;Screw rod
It is detached from the second casting die, then two casting dies and sample is caused to fall, damages Electronic Speculum.
With the mode of screw rod and spring, the pretightning force between casting die and joint ball is adjusted by degree that screw rod screws,
Reduce the manufacture requirement to elasticity itself.
Actuator
As a preferred option, actuator is piezoelectric ceramic tube, and piezoelectric ceramic tube is in hollow tube body, piezoelectric ceramic tube one end
It is fixed with joint ball, the other end is installed on specimen holder;Piezoelectric ceramic tube have the inner surface and the outer surface, one of piezoelectric ceramic tube
Multiple conductive region groups are set on surface, and each conductive region group includes two symmetrical conductive regions, all conductive region phases
Mutually independent, each conductive region has conductor wire;Another surface of piezoelectric ceramic tube is main plot domain conductive part.Main plot domain conductive part
Refer to that all conductive regions on another surface are completely covered in conductive coating.
Preferably, conductive region is mounted on the outer surface of piezoelectric ceramic tube, and main plot domain conductive part is set to piezoelectric ceramic tube
Inner surface.Alternatively, conductive region is mounted on the inner surface of piezoelectric ceramic tube, main plot domain conductive part is set to the appearance of piezoelectric ceramic tube
Face.Such as, conductive region group is uniformly distributed along outer (interior) surface of piezoelectric ceramic tube, then (outer) table in the covering of main plot domain conductive part
Face, and main plot domain conductive part axial length is equal with the axial length of single conductive region or the axial direction of main plot domain conductive part
Length is longer than the axial length of single conductive region.
Preferably, there is insulating coating between adjacent conductive region.
Preferably, the voltage direction of two conductive regions of each conductive region group is on the contrary, only one each conduction region
Domain group is powered, or has multiple conductive region groups to be powered every time.
As a preferred option, joint ball is connected by ball seat with piezoelectric ceramic tube, and ball seat includes fixed with joint ball
Connecting rod and the attachment base fixed with piezoelectric ceramic tube, connecting rod is smaller than joint ball, the cross section of attachment base and piezoelectric ceramic tube
Equidimension.When installation, connecting tube is first passed through to the recess through-hole of pressing member, the recess of pressing member contacts with joint ball, will connect
Adapter tube is fixed with attachment base.
As a preferred option, connecting rod and attachment base are detachable be fastenedly connected.Such as, it is threadedly coupled, key connection etc..
Facilitate the dismounting and replacement of pressing member as a result,.
The present invention has the advantages that 1, with elastic connecting component provide the pretightning force between casting die and joint ball, make casting die
There are stable stiction and kinetic force of friction between joint ball, supports sample and sample holder, casting die with stiction, go
Influence except gravity to sample improves Bit andits control precision.2, the number of components that nanopositioner includes is few, and connection relationship letter
It is clean to be illustrated, it is readily produced, is easy to adjust calibration.3, recess is matched with joint ball, and the position between casting die and joint ball is stablized, pressure
Connection relationship between part is firm, and nanopositioner is avoided to fall off.
Detailed description of the invention
Fig. 1 is the schematic diagram for the piezoelectric ceramic tube that the present invention uses.
Fig. 2 is the schematic diagram of nano-drives.
Fig. 3 is the schematic diagram of the first sample clamp.
Fig. 4 is the schematic diagram of second of sample clamp.
Fig. 5 is the schematic diagram of the third sample clamp.
Fig. 6 is the effect picture that the present invention observes sample under transmission electron microscope, and wherein a.b.c is to use biggish sawtooth wave
The big step-length movement of single step under peak-to-peak value driving, d.e.f are using the single step under the driving of lesser sawtooth wave peak-to-peak value
Small step-length movement.
Specific embodiment
As shown in Fig. 2, multiple degrees of freedom specimen holder, specimen holder is equipped with nanopositioner, and nanopositioner includes actuator
1, joint ball 3 and casting die component, joint ball 3 and actuator 1 are fixed, and casting die component includes at least two casting dies and elastic connection group
Part 4, elastic connecting component 4 connect adjacent casting die, and casting die component embraces joint ball 3, have between casting die and joint ball 3 and pre-tighten
Power.For example piezoelectric ceramic tube is as actuator 1.
Casting die
In some embodiments, each casting die is respectively provided with recessed portion 81 and interconnecting piece 82, and elastic connecting component 4 is set to adjacent pressure
Between the interconnecting piece 82 of part, the composition of recessed portion 81 and the recess of the cooperation of joint ball 3 of all casting dies.Recess connects with 3 line of joint ball
Touching or face contact or point contact;Elastic joint part 82 makes have pretightning force between casting die and joint ball 3, when joint ball 3 is quiet
When only or actuator 1 is slowly moved with joint ball 3, the stiction between joint ball 3 and casting die makes casting die is opposite to shut down
Ball is static.When actuator 1 is with 3 Rapid reset of joint ball, force of sliding friction, joint ball 3 are generated between joint ball 3 and casting die
Casting die is resetted to keep in situ, joint ball 3 is not followed to reset.
The hemispherical perhaps V-arrangement of recess or cone.
Casting die is the plate body of integral type, and recessed portion 81 is located at the center of plate body.
Casting die is located at the outside of joint ball 3.When specimen holder is uprightly placed, upward, two sides are with specimen holder to nanopositioner
Upright when placing, left-right and front-back is outside.Preferably, sample clamping part, all samples clamping part are respectively equipped on each casting die
Form sample clamp 8.When all casting dies assemble in place, sample clamping part is combined into a sample clamp 8, and sample clamp 8 is used
In installation sample.When installation, joint ball 3 is embraced from the two sides of joint ball 3 with casting die, elastic connecting component 4 provides casting die and closes
Save the pretightning force between ball 3.
As shown in Fig. 2, in some embodiments, casting die includes the first casting die 8 and the second casting die 9, the recess of the first casting die 8
Multiple installation positions are respectively uniformly distributed around the recessed portion 91 of portion 81 and the second casting die 9, the corresponding elasticity in each installation position is even
Connected components 4, the installation bit-by-bit of the installation position of the first casting die 8 and the second casting die 9.In this way, 4 one end of elastic connecting component is installed on
The installation position of first casting die 8, the other end are installed on the installation position of the second casting die 9, and the elastic force of elastic connecting component 4 is in one
On straight line, torque is not generated.First casting die 8 is upper, and for the second casting die 9 under, the recess of the second casting die 9 is through-hole.Through-hole it is interior
Wall is hemispherical, V-arrangement or cone etc..First casting die 8 is equipped with sample clamp 8.
Alternatively, the first casting die 8 and the second casting die 9 are located at 3 two sides of joint ball.
There is wearing layer on the recessed portion surface of first casting die 8.There is wearing layer on the recessed portion surface of second casting die 9.Wearing layer has
Conducive to the stabilization for keeping frictional force.3 surface of joint ball has wearing layer or joint ball to be made of wear-resistant material.Such as with aluminium or
Aluminium alloy production, and with the surface of anodized recessed portion with or joint ball surface.
When (or right side, front side, rear side) is swung on the left of actuator, keep nanopositioner mobile to the side by frictional force,
And then keep sample mobile to the side.The moving distance of sample and the opposite constant voltage that applies to above-mentioned two panels conductive coating
Voltage value is directly proportional.The position of sample is observed repeatedly, and adjusts voltage value accordingly, and sample is made to be moved to the position of needs.
Elastic connecting component
As in Figure 2-4, in some embodiments, elastic connecting component 4 is elastic (such as silicon made of spring or elastic material
Rubber column gel column, rubber column etc.), 4 one end of elastic connecting component and the first casting die 8 are fixed, and the other end and the second casting die 9 are fixed.Two pressures
After part embraces joint ball 3, elastic connecting component 4 is in deformed state, the restoring force of elastic connecting component 4 provide two casting dies with
Pretightning force between joint ball 3.
Alternatively, elastic connecting component is made of screw rod 41 and spring 42, spring 42 is set in screw rod 41, and spring 42 is located at spiral shell
Between bar 41 and the first casting die 8, the installation position of the second casting die 9 is the screw hole engaged with screw rod 41.Screw rod 41 and the second casting die 9
After the engagement of installation position, spring 42 be in confined state, and spring 42 pushes away the first casting die 8 to the second casting die 9, the offer of spring 42 the
One casting die 8, the second casting die 9 are with the pretightning force between joint ball 3.The installation position of first casting die 8 is through-hole, between through-hole and screw rod 41
Gap cooperation.Without friction between through-hole and screw rod 41, be conducive to the first casting die of promotion 8 of spring 42.
In some embodiments, screw rod 41 stretch out the second casting die 9 mounting hole 92 or screw rod 41 and the second casting die 9 it
Between have fixed part;Or screw rod 41 sequentially passes through the first casting die 8, the second casting die 9 is engaged with nut.For example, such as the second casting die 9
After being installed in place, screw rod 41 and the second casting die 9 are welded and fixed or are adhesively fixed.This is because 3 shuttling movement of joint ball
And when the first casting die 8 and the second casting die 9 being driven to be displaced, the first casting die 8 and 9 whipping of the second casting die will cause screw rod 41 and the second pressure
Impact between part 9 causes screw rod 41 to loosen and is even detached from the second casting die 9;Screw rod 41 loosens the accurate control that will affect position;
Screw rod 41 is detached from the second casting die 9, then two casting dies and sample is caused to fall, and damages Electronic Speculum.Screw rod and the second casting die are fixed, or
Impact when nut is arranged in person, the purpose of reserved redundant segments screw thread is buffering or resistance nanopositioner whipping, avoids screw rod de-
It causes nanopositioner and sample to fall off from the second casting die 9, keeps being stably connected between casting die and joint ball.
With the mode of screw rod 41 and spring 42, adjusted between casting die and joint ball 3 by degree that screw rod 41 screws
Pretightning force reduces the manufacture requirement to elasticity itself.Elastic connecting component 4 provides lasting, steady between casting die and joint ball
Fixed pressure, to make between casting die and joint ball that there are stable frictional force.
Actuator
As shown in Figure 1, in some embodiments, actuator 1 is piezoelectric ceramic tube, and piezoelectric ceramic tube is in hollow tube body, pressure
Electroceramics pipe one end and joint ball 3 are fixed, and the other end is installed on specimen holder;Piezoelectric ceramic tube has the inner surface and the outer surface, pressure
Multiple conductive region groups are set on one surface of electroceramics pipe, and each conductive region group includes two symmetrical conductive regions
13, all conductive regions 13 are mutually indepedent, and each conductive region 13 has conductor wire;Another surface of piezoelectric ceramic tube is main plot
Domain conductive part 12.Main plot domain conductive part 12 refers to that all conductive regions 13 on another surface are completely covered in conductive coating.
As shown in Figure 1, conductive region 13 is mounted on the outer surface of piezoelectric ceramic tube, main plot domain conductive part 12 is made pottery set on piezoelectricity
The inner surface of porcelain tube.Alternatively, conductive region 13 is mounted on the inner surface of piezoelectric ceramic tube, main plot domain conductive part 12 is made pottery set on piezoelectricity
The outer surface of porcelain tube.Such as, 13 groups of conductive region outer (interior) surfaces along piezoelectric ceramic tube are uniformly distributed, then main plot domain conductive part 12
(outer) surface in covering, and the axial length of main plot domain conductive part 12 and the axial length of single conductive region 13 are equal or whole
The axial length in zone conducts current portion 12 is longer than the axial length of single conductive region 13.There is insulation between adjacent conductive region 13
Coating.The voltage direction of two conductive regions 13 of 13 groups of each conductive region is on the contrary, each 13 groups of only one conductive region
It is powered, or has the 13 groups of energizations of multiple conductive regions every time.
In some embodiments, joint ball 3 is connected by ball seat 2 with piezoelectric ceramic tube, and ball seat 2 includes solid with joint ball 3
Fixed connecting rod and the attachment base fixed with piezoelectric ceramic tube, connecting rod is smaller than joint ball, the cross of attachment base and piezoelectric ceramic tube
Section equidimension.When installation, connecting tube is first passed through to the recess through-hole of pressing member, the recess of pressing member is contacted with joint ball 3,
Connecting tube and attachment base are fixed.
The bottom end of piezoelectric ceramic tube 1 is fixed, the conductive coating of the medial surface of piezoelectric ceramic tube 1 is welded to a conducting wire
And keep being grounded, four conducting wires are welded on four conductive coatings of 1 lateral surface of piezoelectric ceramic tube, it is another to terminate to electricity
The each output end for pressing amplifier, then terminates to each input of voltage amplifier on function signal generator.The sample
Two freedom degrees of bar can respectively drive.Any freedom degree of specimen holder is driven, sample is made to be moved to needs in the freedom degree
Position method are as follows: by conducting wire on 1 lateral surface of piezoelectric ceramic tube symmetrical two panels conductive coating apply it is positive and negative opposite
Sawtooth wave.The sawtooth wave can be continuously, be also possible to sectors punching, as shown in Figure 3.Conductive region more than 13, joint ball 3
The possible direction of motion is more.
To continuous sawtooth wave, preferred parameter be peak-to-peak value 100V, frequency 100Hz hereinafter, slew rate 100V/ μ s with
On.The appropriate peak-to-peak value that reduces can reduce moving step sizes, but peak-to-peak value too low (in some cases, being lower than 40V) can make to transport
Dynamic step-length falls abruptly to zero, and reason may be related with the microstructure of rubbing surface.Peak-to-peak value can puncture piezoelectricity pottery when being higher than 100V
Porcelain destroys piezoelectric ceramic tube 1.Frequency can excite the intrinsic vibration of piezoelectric ceramic tube 1 or single unit system structure when being higher than 100HZ,
The movement for making joint ball 3 is no longer " slowly, quickly " moving in plane, and the driving principle of nanopositioner is not able to satisfy, sample
Product cannot move.The movement step number generated in the unit time can be reduced by reducing frequency, control the movement velocity of sample.Slew rate
3 acceleration of motion of sliding phase joint ball can be made too small when lower than 100V/ μ s, frictional force is able to maintain moving component and follows joint
The movement of ball 3 cannot generate long stroke movement without generating sliding, sample by accumulating each step.
The position that sample is observed by other observation devices (such as optical microscopy, electron microscope), works as sample
When moving near target position, applies opposite constant voltage to above-mentioned symmetrical conductive region, make the one of piezoelectric ceramic tube 1
Side extends, and the other side is shortened, and aggregate performance is bending, and then makes the joint ball 3 for being fixed on 1 one end of piezoelectric ceramic tube
It is mobile to side.
In some embodiments, connecting rod and attachment base are detachable be fastenedly connected.Such as, it is threadedly coupled, key connection etc..
Facilitate the dismounting and replacement of pressing member as a result,.
As shown in figure 3, sample clamp is casing, casing 6 and upper casting die 8 integrally, run through on 6 wall of casing and are equipped with fastening spiral shell
Nail 7.By in rodlike or tubular specimen insertion casing 6, sample is compressed with fastening screw 7, then completes the clamping of sample.
Another form of sample clamp as shown in Figure 4, sample clamp are circular cone, 8 one of circular cone 61 and top board.By powder
Last shape sample is adhesive in 61 vertex of circular cone, that is, completes the clamping of sample.
Another form of sample clamp as shown in Figure 5, sample clamp includes matrix 62, gasket 621 and fastening screw
622;Matrix 62 divides for interconnecting piece and clamping part, and interconnecting piece is the cylindrical body fixed with top board, and clamping part is that cutting has plane
Imperfect cylindrical body, gasket 621 is anchored on clamping part by fastening screw 622, uses between the plane and gasket 621 of clamping part
In clamping sample 623.
In the case where lacking any element specifically disclosed herein, limitation, may be implemented illustrated and described herein
Invention.Used terms and expressions method is used as the term of explanation rather than limits, and is not intended in these terms and table
Up to any equivalent for excluding shown and described feature or part thereof in the use of method, and it should be realized that various remodeling exist
It is all feasible in the scope of the present invention.It is therefore to be understood that although specifically being disclosed by various embodiments and optional feature
The present invention, but the modifications and variations of concept as described herein can be used by those of ordinary skill in the art, and recognize
It is fallen into for these modifications and variations within the scope of the present invention of the appended claims restriction.
It is described herein or record article, patent, patent application and every other document and can electronically obtain
The content of information to a certain extent in full include herein by reference, just as each individual publication by specific and single
Solely point out by reference.Applicant retains from any of any this article, patent, patent application or other documents
And all material and information are incorporated into the right in the application.