1. A nested scanning probe microscope comprises a shell (1), and is characterized by further comprising a stepping motor, an insulating tube (3), an insulating counterweight frame (4) and a scanning head (5), which are coaxially sleeved in sequence along an axial direction; wherein the content of the first and second substances,

the stepping motor is arranged on the inner wall of the shell, and the insulating pipe is circumferentially arranged on the inner wall of the stepping motor; an elastic part (7) is arranged between the outer wall of the insulation counterweight frame and the insulation pipe, and the insulation counterweight frame is in sliding fit with the inner wall of the insulation pipe through the stress of the elastic part; the scanning head is mounted on the insulating counterweight frame and is provided with a testing end (50), and the testing end comprises a probe (9) for scanning a sample;

the stepping motor is used for driving the insulation counterweight frame and the scanning head to step along the axial direction.

2. The nested scanning probe microscope of claim 1, wherein the stepper motor has a fixed end (10) and a free end (11) disposed opposite; the insulating pipe is circumferentially arranged on the inner wall of the free end; the insulating weight frame comprises a connecting part (41) and a sliding part (42), and the sliding part is in sliding fit in the insulating pipe along the axial direction through the elastic piece; the scanning head is mounted on the connecting portion.

3. The nested scanning probe microscope of claim 2, wherein the testing end of the scanning head corresponds to the free end.

4. The nested scanning probe microscope of claim 3, wherein the sample is located on the free end side and spaced from the probe.

5. The nested scanning probe microscope of claim 3, wherein the probe is positioned on the side of the free end and spaced from the sample.

6. The nested scanning probe microscope of claim 2, wherein the testing end of the scanning head corresponds to the fixed end at which the sample is located.

7. The nested scanning probe microscope of any one of claims 1 to 6, wherein the stepper motor is any one of a piezoelectric tube, a piezoelectric stack of a plurality of piezoelectric sheets stacked.

8. The nested scanning probe microscope of claim 1, wherein the stepper motor is a three-friction stepper motor, and the insulating tube is circumferentially and uniformly disposed on an inner wall of the stepper motor.

9. The nested scanning probe microscope of claim 1, wherein the stepper motor outer wall is fixedly connected to the housing; the insulating tube is fixedly connected with the inner wall of the stepping motor; the scanning head is fixedly connected with the insulation counterweight frame.

Background

Scanning Probe Microscopy (SPM) is widely used in various research fields because of its unique and excellent microscopic characterization capability, and is an important tool for exploring the microscopic world and an important means for people to manipulate and transform atoms and molecules. With the development of scientific technology and the expansion of an SPM application scene, an SPM structure is gradually optimized. The SPM mirror body which has the advantages of compact structure, strong rigidity, vibration resistance, small volume, small thermal drift and high space utilization rate, particularly the utilization rate of the piezoelectric material, becomes a target which is continuously searched by scientists.

Scanning probe microscopes typically include three core components: a stepper motor, a scan head, and a sample. The scanning head is used for carrying a probe to scan on the surface of the sample, and the stepping motor is used for pushing the scanning head to the surface of the sample. The stepping motor is made of piezoelectric materials, the piezoelectric stepping motor is various in types, and the core design of the piezoelectric stepping motor has two motion modes: one is to drive the stepping motor to move along the z-axis direction by friction force or inertia force, wherein the z-axis is perpendicular to the sample surface to be measured, so as to push the scanning head placed in front of the stepping motor to approach the sample surface; and the other is that the transverse inertia force is used for swinging the heavy object block arranged on the transverse inertia force to move along the z-axis, so that the scanning head on the heavy object block is driven to be close to the surface of the sample. In any of the above manners, the stepping motor and the scanning head occupy a certain space independently, and the waste of the internal space of the stepping motor is serious, for example, the inertial motor is made of a hollow piezoelectric scanning tube, and the internal space is almost completely wasted, which causes the problems that the SPM structure is not compact enough, the rigidity is weakened, the space in the stepping direction of the motor occupies a large space, and the like.

In Chinese patent application with the application number of 201711188898.X, a double-piezoelectric-tube nested mechanical parallel stable scanner is provided, and a scanning head with increased wall thickness and enhanced stability is formed by coaxially nesting two piezoelectric tubes. In the Chinese patent application with the application number of 201010254442.0, a three-friction piezoelectric stepper driven by nested double piezoelectric tubes and a step scanner are provided, which relate to a piezoelectric stepper, and the large-thrust and high-precision three-friction stepper motor is realized by coaxially nesting two piezoelectric tubes. None of the above-mentioned known patents addresses the problem of large motor step direction space occupation.

Disclosure of Invention

The purpose of the invention is as follows: the nested scanning probe microscope has the advantages of compact structure, small volume and high space occupancy rate and can improve the scanning quality.

The technical scheme is as follows: a nested scanning probe microscope comprises a shell, a stepping motor, an insulating tube, an insulating counterweight frame and a scanning head, wherein the stepping motor, the insulating tube, the insulating counterweight frame and the scanning head are sequentially coaxially sleeved along an axial direction; the stepping motor is arranged on the inner wall of the shell, and the insulating pipe is circumferentially arranged on the inner wall of the stepping motor; an elastic part is arranged between the outer wall of the insulation counterweight frame and the insulation pipe, and the insulation counterweight frame is in sliding fit with the inner wall of the insulation pipe through the stress of the elastic part; the scanning head is arranged on the insulation counterweight frame and is provided with a testing end, and the testing end comprises a probe for scanning a sample; the stepping motor is used for driving the insulation counterweight frame and the scanning head to step along the axial direction.

Preferably, the stepping motor has a fixed end and a free end which are oppositely arranged; the insulating pipe is circumferentially arranged on the inner wall of the free end; the insulation counterweight frame comprises a connecting part and a sliding part, and the sliding part is in sliding fit in the insulation pipe along the axial direction through the elastic piece; the scanning head is mounted on the connecting portion. The insulating counterweight frame plays an insulating role and has a counterweight effect so as to increase the inertia force.

Preferably, the testing end of the scanning head corresponds to the free end.

Preferably, the sample is located on the free end side and spaced from the probe.

Preferably, the probe is arranged on one side of the free end and is arranged at an interval with the sample, so that the probe is convenient to replace.

Preferably, the testing end of the scanning head corresponds to the fixed end, and the sample is located at the fixed end.

Preferably, the stepping motor is any one of a piezoelectric tube and a piezoelectric stack in which a plurality of piezoelectric sheets are stacked.

Preferably, the stepping motor is a three-friction stepping motor, and the insulation pipes are circumferentially and uniformly arranged on the inner wall of the three-friction stepping motor.

Preferably, the outer wall of the stepping motor is fixedly connected with the shell; the insulating tube is fixedly connected with the inner wall of the stepping motor; the scanning head is fixedly connected with the insulation counterweight frame.

Has the advantages that: compared with the prior art, the invention has the advantages that:

1. the nested scanning probe microscope adopts the structural design of coaxially nesting the stepping motor, the insulating counterweight frame, the insulating tube and the scanning head, realizes the effects of compact structure, small volume and high space utilization rate, has anti-interference and high degree of symmetry, reduces thermal drift caused by temperature change, and improves the quality of scanning imaging;

2. the stepping motor adopts any one of a piezoelectric tube, a piezoelectric stack or a three-friction stepping motor to meet different requirements, such as rigidity requirement, thrust requirement and precision requirement;

3. the nested scanning probe microscope has various structures, wider applicability, high stability and capability of realizing accurate stepping.

Drawings

FIG. 1 is a schematic structural diagram of a nested scanning probe microscope according to a first embodiment;

FIG. 2 is a schematic structural view of a nested scanning probe microscope according to the second embodiment;

FIG. 3 is a schematic structural view of a nested scanning probe microscope according to a third embodiment;

FIG. 4 is a schematic structural view of a nested scanning probe microscope according to a fourth embodiment;

FIG. 5 is a schematic structural diagram of a nested scanning probe microscope according to the fifth embodiment.

Detailed Description

The technical scheme provided by the invention is explained in detail in the following with the accompanying drawings.

As shown in fig. 1, in a first embodiment, the nested scanning probe microscope includes a housing 1, and further includes a stepping motor, an insulating tube 3, an insulating weight frame 4, and a scanning head 5 coaxially sleeved in sequence along an axial direction.

Step motor is piezoelectric tube 2, piezoelectric tube 2 is hollow tubulose structure, piezoelectric tube 2 has a relative stiff end 10 and a free end 11, insulating tube 3 winds the axial is circumference set up in on the 11 inner walls of free end, the outer wall of stiff end 10 is fixed in through 6 bonds of fixed block on the casing 1.

The insulating tube 3 is fixedly bonded on the free end 11; an elastic part 7 is arranged between the inner wall of the insulating tube 3 and the outer wall of the insulating counterweight frame 4, the insulating counterweight frame 4 slides up and down relative to the inner wall of the insulating tube 3 through the elasticity of the elastic part 7 when stressed, the elastic part 7 is a spring piece, and the spring piece and the insulating counterweight frame 4 are elastically pressed into point contact or line contact. The scanning head 5 is installed in the insulation counterweight frame 4, one end of the scanning head 5, which deviates from the insulation counterweight frame 4, is a testing end 50, the testing end 50 comprises a probe 9 used for scanning a sample 8, the sample 8 is arranged on a carrying platform 12, and the probe 9 is installed on the testing end 5.

The insulating weight frame 4 comprises a connecting part 41 and a sliding part 42, and the sliding part 42 is in sliding fit in the insulating tube 3 along the axial direction through the elastic piece 7; the connecting portion 41 corresponds to the fixed end 10; the scan head 5 is mounted on the connecting portion 41, one end of the scan head 5 is bonded to the connecting portion 41, and the testing end 50 of the scan head 5 is a free end and corresponds to the free end 11.

The insulating tube 3 is used for separating the piezoelectric tube 2 from the scanning head 5 and the probe 9 thereof in the insulating counterweight frame 4 to play an insulating function, so as to prevent the piezoelectric tube 2 from electric leakage to influence the quality of scanning imaging of the probe 9. The insulating tube 3 also corresponds to a sliding guide rail, and the insulating counterweight frame 4 slides relative to the insulating tube 3 through the elastic piece 7.

The insulation counterweight frame 4 is an insulation structural member, the insulation counterweight frame 4 has an insulation effect, has a large self mass and a counterweight effect, so that the inertia force is increased, and the insulation counterweight frame can move relative to the insulation tube 3 more smoothly.

The piezoelectric tube 2 is provided with a time sequence control signal which comprises a slowly-changing signal and a reverse polarity pulse signal, and the time sequence control signal is repeatedly arranged, so that the probe 9 scans the surface of the sample 8 when the insulating counterweight frame 4 and the scanning head 5 are repeatedly stepped until the probe 9 roughly approaches the sample 8.

When the nested scanning probe microscope works, the piezoelectric tube 2 is driven by the slow varying signal to extend slowly, the free end 11 of the piezoelectric tube 2 can slowly drive the insulating counterweight frame 4 and the scanning head 5 to extend together along the axial direction, namely along the telescopic direction, and then the piezoelectric tube 2 is driven by the reversed polarity pulse signal, namely the reversed voltage driving signal, to shrink rapidly. Due to the existence of the inertia force, the insulation counterweight frame 4, the scanning head 5 and the probe 9 move downwards relative to the insulation tube 3 and the elastic piece 7 for a certain distance, namely, a step is generated towards the sample 8; repeating the steps, the scanning head 5 can drive the probe 9 to approach the sample 8 roughly; after the probe 9 reaches the surface of the sample 8, the scanning head 5 scans the surface of the sample 8 through the probe 9.

As shown in fig. 2, the second embodiment is different from the first embodiment in that the positions of the probe 9 and the sample 8 are interchanged, that is, the sample 8 is located on the testing end 50, and the probe 9 is disposed on the stage 12. The second embodiment can facilitate the replacement of the probe 9, and the nested scanning probe microscope working in the vertical direction in the first embodiment can form a vertically and horizontally transposed mirror structure by inversion, so that the nested scanning probe microscope works in the horizontal direction to adapt to scanning the sample 8 in a special environment.

As shown in fig. 3, the third embodiment is different from the first and second embodiments in that the connecting portion 41 of the insulating weight frame 4 corresponds to the free end 11 of the piezoelectric tube 2, the test end 50 of the scanning head 5 corresponds to the fixed end 10 of the piezoelectric tube 2, the stage 12 is mounted on the fixed end 10, the probe 9 is mounted on the test end 50, and the sample 8 is adhesively fixed to the stage 12. By making the free end 11 of the piezoelectric tube 2 contract slowly and then extend rapidly, the insulating counterweight frame 4 drives the scanning head 5 to move up one step due to the inertia force, gradually approaching the surface of the sample 8. After the probe 9 reaches the surface of the sample 8, the scanning head 5 can drive the probe 9 to scan on the surface of the sample 8 through a control signal.

As shown in fig. 4, a fourth embodiment is different from the first, second and third embodiments in that the stepping motor does not use the piezoelectric tube 2, but uses a piezoelectric stack 22 formed by stacking a plurality of piezoelectric sheets to realize stepping driving, and the nested scanning probe microscope driven by the piezoelectric stack 22 operates in the same manner as the first embodiment, and the piezoelectric stack 22 can provide a large thrust and has high stability.

As shown in fig. 5, in the fifth embodiment, the stepping motor is a triple-friction stepping motor 23, the triple-friction stepping motor 23 needs to be divided into a plurality of electrodes 20, the insulating tube 3 is circumferentially and uniformly disposed on the inner wall of the triple-friction stepping motor 23, the elastic members 7 are uniformly disposed between the inner wall of the insulating tube 3 and the insulating weight frame 4, and the triple-friction stepping motor 23 can achieve the effects of high thrust and high precision.

According to the invention, the scanning head 5 is nested in the stepping motor, the internal space of the stepping motor is utilized, the axial length of the microscope is reduced, the space utilization rate of the nested scanning probe microscope is increased, the compactness and the rigidity of the whole nested scanning probe microscope are increased, the structure is compact and more anti-interference, accurate stepping can be realized, the high symmetry is realized, the thermal drift and the electric fluctuation caused by temperature change can be greatly reduced, the volume of the whole nested scanning probe microscope is reduced, and the scanning imaging quality is improved.