A high-Q dynamic probe for measuring atomic forces

Abstract

This invention discloses a high-Q dynamic probe for measuring atomic force, comprising a needle holder, a base, a cantilever beam, a needle tip, discrete piezoresistive units, connecting wires, conductive flying wires, and a conductive backing plate. The base and conductive backing plate are located at opposite ends of the needle holder. The cantilever beam extends outward from the base in a direction away from the conductive backing plate. The cantilever beam has a perforated portion. The needle tip is located at the top of the end of the cantilever beam. The discrete piezoresistive units are located at the root of the cantilever beam. The connecting wires are located on the base. The first end of the connecting wire is connected to the discrete piezoresistive units, and the second end of the connecting wire is connected to the conductive backing plate. This high-Q dynamic probe for measuring atomic force has advantages such as improving the yield rate of piezoresistive probes, reducing heat generation, facilitating needle replacement, and increasing measurement sensitivity.

Description

Technical Field

[0001] This invention relates to an atomic force probe, and more particularly to a high-Q dynamic probe for measuring atomic forces. Background Technology

[0002] An atomic force microscope (AFM) is an important instrument for analyzing surface morphology and electromagnetic properties at atomic resolution. AFM probes, due to their application being limited to AFM, are considered consumables for this high-tech instrument. AFM probes have significant application value and promising prospects in industrial production and basic scientific research, including in-situ characterization of battery electrode materials, measurement and inspection in integrated circuit and wafer manufacturing, surface physical analysis, Young's modulus analysis of materials, and nanoindentation mechanical measurement.

[0003] An atomic force probe (AFP) is a miniature force sensor manufactured using semiconductor micro-nano fabrication technology. The tip of an AFP is sharp and pointed, only about the size of a few dozen atoms. The tip radius of curvature is approximately 20 nanometers, achieving a spatial resolution of 20 nanometers. AFPs are mainly divided into two types: optical detection AFPs and self-inductive piezoresistive AFPs. Optical detection AFPs have a thin metal reflective film coated on their surface to reflect the incident laser beam. Self-inductive piezoresistive AFPs do not have a metal reflective film on their surface; the detection unit is a piezoresistive sensor fabricated using semiconductor micro-nano fabrication technology. AFPs are the most important consumables in atomic force measurements, consumed in large quantities and are very expensive.

[0004] The quality of an atomic force probe (AFP) directly determines the sensitivity of atomic force measurements. When an AFP approaches a sample surface, a weak attractive or repulsive force, known as atomic force, occurs between the atoms at the probe tip and the atoms on the sample surface. Tiny changes in this atomic force cause a slight deflection and bending of the cantilever beam. In optically detected AFP deflection and bending deformation, to accurately measure this deflection and bending, a laser beam is typically used to illuminate one side of the cantilever beam coated with a reflective metal film, reflecting the light onto a photodetector. As the cantilever beam deflects and bends, the reflected laser spot moves on the photodetector, causing one side of the photodetector to receive more light. This change is converted into an electrical signal, which provides crucial information about the degree of bending of the probe perpendicular to the sample surface. This crucial information allows researchers to obtain detailed mechanical measurements of the microscopic world.

[0005] In laser interferometry, to measure the minute deflection and bending of a cantilever beam, a laser beam is perpendicularly incident on a side of the cantilever beam coated with a metallic reflective film, generating reflected light. The incident and reflected light form interference fringes on a photodetector. As the cantilever beam deflects and bends, the intensity of the interference light changes. This changing optical signal is converted into an electrical signal, which provides crucial information about the degree of bending of the probe perpendicular to the sample surface. Similarly, this vital information provides researchers with detailed mechanical measurements of the microscopic world.

[0006] In practical applications of atomic force probes (AFPs) for measuring atomic forces, optical AFPs require an external laser as a light source and an optical path system. Stable laser outputs are expensive, significantly increasing the cost of the probe. When the laser shines on the back of the optical probe, some of it inevitably hits the sample, increasing experimental variables. For light-sensitive materials like photoresist, the light can even cause retrograde deformation, damaging the sample. The optical path system, composed of numerous optical components, suffers from drawbacks such as large overall size, loose structure, and poor rigidity. AFP measurements are easily affected by external environmental vibrations and are incompatible with confined sample cavities, especially in extreme physical environments like extremely low temperatures and strong magnetic fields. Furthermore, the optical path system must possess good temperature stability. Temperature changes can cause relative movement of optical components due to thermal expansion and contraction, disrupting the calibrated optical path. This necessitates recalibrating the optical path after temperature-changing experiments, resulting in additional time and effort and reduced experimental efficiency. This is particularly problematic for rotational measurements under strong magnetic fields, requiring the experimental setup to rotate within a confined magnetic field space. However, optical systems are difficult to insert into such testing environments. They also cannot rotate flexibly within them.

[0007] Self-inductive piezoresistive probes require no external light source or complex optical path system, and there is no light interference during imaging. They are compact in structure and small in size, allowing for flexible rotation within confined sample cavities. Therefore, while optically-based atomic force probes are incompatible with measuring rotational forces under strong magnetic fields, piezoresistive probes offer an ideal solution. Consequently, due to their small size, ease of integration, and lack of optical interference, piezoresistive probes are becoming increasingly popular as force sensors.

[0008] In atomic force microscopy, the quality factor (Q-factor) of a cantilever beam characterizes its response. Cantilever beams typically possess a high Q-factor. A higher Q-factor makes the probe more sensitive to the sample's action during imaging, thereby improving imaging resolution. Piezoresistive probes suffer from problems such as low yield, low mechanical quality factor (Q-factor), low force measurement sensitivity, high thermal noise, low signal-to-noise ratio, and severe heat generation at extremely low temperatures.

[0009] The piezoresistive properties of piezoresistive probes are fabricated using an ion implantation process, which has a certain yield rate. Low yield directly leads to high defect rates in wafer manufacturing, significantly increasing the production and usage costs of the probes. Impurity ions are implanted into the silicon substrate with specific incident energy and angle, forming a doped region with a certain depth and doping concentration. Therefore, the incident energy, incident angle, doping concentration, and depth all need to be precisely controlled. The doped region then undergoes annealing to activate the impurities and eliminate lattice defects generated during ion implantation; the annealing time and temperature must also be precisely controlled. After annealing, the doped region forms the piezoresistive structure. The yield rate is a crucial issue that urgently needs to be addressed in the large-scale application of piezoresistive probes.

[0010] The mechanical quality factor (Q-value) of a piezoresistive probe is approximately 100 under ambient temperature and atmospheric conditions, and approximately 800 under vacuum conditions at room temperature. A Q-value that is too low is problematic. The force measurement sensitivity of a piezoresistive probe is directly proportional to its Q-value; an excessively low Q-value will reduce the force measurement sensitivity. During operation, the piezoresistive probe generates Joule heating, which is directly radiated to and heats the sample. This heating effect is particularly pronounced in cryogenic mechanical measurements, and can even disrupt the cryogenic conditions. Increasing the resistance of a single piezoresistive element can reduce its heating power, but it also significantly increases the electrical noise of the piezoresistive probe, greatly reducing the signal-to-noise ratio of the resistance signal and thus decreasing the sensitivity of force measurements.

[0011] As a consumable, probes need to be replaced after a period of use. When replacing probes, researchers must do so manually. Because the probe base is very small, the probe must be gently picked up with tweezers, which easily leads to it slipping or flying off, causing the fragile cantilever beam to break upon impact. Even with careful operation by experienced researchers, errors can still occur, resulting in significant probe waste.

[0012] Therefore, there is an urgent need to design a high-Q piezoresistive probe to solve the problems of low yield, low mechanical quality factor Q, low force measurement sensitivity, high heat generation and high needle replacement error rate of existing piezoresistive probes. At the same time, it is expected that the probe is suitable for measuring rotational force in extreme physical environments such as ultra-low temperature, ultra-high vacuum and strong magnetic field. Summary of the Invention

[0013] To avoid the shortcomings of the existing technology, the present invention provides a high Q-value dynamic probe for measuring atomic force, thereby improving the yield of piezoresistive probes, reducing heat generation, facilitating probe replacement, and improving measurement sensitivity.

[0014] The present invention adopts the following technical solution to solve the technical problem.

[0015] The present invention provides a high-Q dynamic probe for measuring atomic force, comprising a needle holder 1, a base 2, a cantilever beam 3, a needle tip 4, a discrete piezoresistive unit 5, a connecting wire 6, a conductive flying wire 7, and a conductive backing plate 8;

[0016] The base 2 and the conductive liner 8 are respectively located at both ends of the needle seat 1; the cantilever beam 3 extends outward on the base 2 in a direction away from the conductive liner 8;

[0017] The cantilever beam 3 is provided with a hollow part 31; the end of the cantilever beam 3 away from the needle seat 1 is the cantilever beam end, and the needle tip 4 is provided at the top of the cantilever beam end;

[0018] The cantilever beam 3 has a root end near the needle seat 1; the discrete piezoresistive unit 5 is provided on the root end of the cantilever beam; the discrete piezoresistive unit 5 includes a first discrete piezoresistive unit 5a and a second discrete piezoresistive unit 5b.

[0019] The base 2 is provided with the connecting wire 6; the first end of the connecting wire 6 is connected to the discrete piezoresistive unit 5, and the second end of the connecting wire 6 is connected to the conductive liner 8.

[0020] The structural features of the high-Q dynamic probe for measuring atomic forces of the present invention also include:

[0021] Furthermore, the first discrete piezoresistive unit 5a and the second discrete piezoresistive unit 5b are disposed on the same cantilever beam 3.

[0022] Furthermore, the hollow portion 31 extends from the end of the cantilever beam to the root of the cantilever beam; the first discrete piezoresistive unit 5a and the second discrete piezoresistive unit 5b are located on both sides of the hollow portion 31.

[0023] Furthermore, the hollow portion 31 extends from the end of the cantilever beam to the discrete piezoresistive unit 5; the first discrete piezoresistive unit 5a and the second discrete piezoresistive unit 5b are located on the side of the hollow portion 31 away from the end of the cantilever beam.

[0024] Furthermore, the second end of the connecting wire 6 is connected to the conductive liner 8 via a conductive flying wire 7.

[0025] Furthermore, the conductive substrate 8 includes a first conductive substrate 8a, a second conductive substrate 8b, a third conductive substrate 8c, and a fourth conductive substrate 8d.

[0026] Furthermore, the connecting wire 6 includes a first connecting wire 6a, a second connecting wire 6b, a third connecting wire 6c, and a fourth connecting wire 6d;

[0027] The first discrete piezoresistive unit 5a is connected to the first conductive substrate 8a via the first connecting wire 6a;

[0028] The first discrete piezoresistive unit 5a is connected to the second conductive substrate 8b via the second connecting wire 6b;

[0029] The second discrete piezoresistive unit 5b is connected to the third conductive substrate 8c via a third connecting wire 6c.

[0030] The second discrete piezoresistive unit 5b is connected to the fourth conductive substrate 8d via the fourth connecting wire 6d.

[0031] Furthermore, the conductive flying wire 7 includes a first conductive flying wire 7a, a second conductive flying wire 7b, a third conductive flying wire 7c, and a fourth conductive flying wire 7d;

[0032] The first connecting wire 6a is connected to the first conductive liner 8a via the first conductive flying wire 7a;

[0033] The second connecting wire 6b is connected to the second conductive substrate 8b via the second conductive flying wire 7b;

[0034] The third connecting wire 6c is connected to the third conductive liner 8c via the third conductive flying wire 7c.

[0035] The fourth connecting wire 6d is connected to the fourth conductive liner 8d via the fourth conductive flying wire 7d.

[0036] Furthermore, the needle holder 1 is provided with a groove, and the conductive liner 8 is located within the groove.

[0037] Furthermore, a magnetic coating layer is provided on the needle tip 4 at the end of the cantilever beam.

[0038] Compared with existing technologies, the beneficial effects of this invention are reflected in:

[0039] This invention discloses a high-Q dynamic probe for measuring atomic force, comprising a needle holder, a base, a cantilever beam, a needle tip, discrete piezoresistive units, connecting wires, conductive flying wires, and a conductive backing plate; the base and the conductive backing plate are respectively located at both ends of the needle holder; the cantilever beam extends outward from the base along a direction away from the conductive backing plate; the cantilever beam has a hollow portion; the needle tip is located at the top of the end of the cantilever beam; the discrete piezoresistive units are located at the root of the cantilever beam; the connecting wires are located on the base; the first end of the connecting wire is connected to the discrete piezoresistive units, and the second end of the connecting wire is connected to the conductive backing plate.

[0040] The high-Q dynamic probe for measuring atomic force of the present invention has the advantages of improving the yield of piezoresistive probes, reducing heat generation, facilitating probe replacement, and improving measurement sensitivity. Attached Figure Description

[0041] Figure 1 This is a front view (first cutout method) of a high-Q dynamic probe for measuring atomic force according to the present invention.

[0042] Figure 2 This is a left view of a high-Q dynamic probe for measuring atomic forces according to the present invention.

[0043] Figure 3 This is a schematic diagram of a second hollowing method for a high-Q dynamic probe for measuring atomic forces according to the present invention.

[0044] The present invention will be further described below through specific embodiments and in conjunction with the accompanying drawings. Detailed Implementation

[0045] See Figures 1-3 The present invention provides a high-Q dynamic probe for measuring atomic force, comprising a needle holder 1, a base 2, a cantilever beam 3, a needle tip 4, a discrete piezoresistive unit 5, a connecting wire 6, a conductive flying wire 7, and a conductive backing plate 8.

[0046] The base 2 and the conductive liner 8 are respectively located at both ends of the needle seat 1; the cantilever beam 3 extends outward on the base 2 in a direction away from the conductive liner 8;

[0047] The cantilever beam 3 is provided with a hollow part 31; the end of the cantilever beam 3 away from the needle seat 1 is the cantilever beam end, and the needle tip 4 is provided at the top of the cantilever beam end;

[0048] The cantilever beam 3 has a root end near the needle seat 1; the discrete piezoresistive unit 5 is provided on the root end of the cantilever beam; the discrete piezoresistive unit 5 includes a first discrete piezoresistive unit 5a and a second discrete piezoresistive unit 5b.

[0049] The base 2 is provided with the connecting wire 6; the first end of the connecting wire 6 is connected to the discrete piezoresistive unit 5, and the second end of the connecting wire 6 is connected to the conductive liner 8.

[0050] like Figures 1-3As shown, this invention provides a high-Q dynamic probe for measuring atomic forces. A cantilever beam 3 extends outward from a base 2, and the cantilever beam 3 is integrally formed with the base 2. The cantilever beam has a hollowed-out portion. A discrete piezoresistive unit is located at the root of the cantilever beam. A needle tip is located at the end of the cantilever beam. Connecting wires for the discrete piezoresistive units are provided on the base. The base is mounted on a needle holder, which has a conductive liner. The connecting wires and the conductive liner are connected by conductive flying wires. This invention's high-Q dynamic probe for measuring atomic forces improves probe yield, increases the mechanical quality factor (Q value), reduces thermal noise, improves the signal-to-noise ratio, enhances force measurement sensitivity, and reduces heat generation. It also features easy needle replacement, expanded application areas, and is particularly suitable for measuring rotational forces in extreme physical environments such as extremely low temperatures, ultra-high vacuum, and strong magnetic fields.

[0051] In specific implementation, the first discrete piezoresistive unit 5a and the second discrete piezoresistive unit 5b are disposed on the same cantilever beam 3.

[0052] In practice, two or more cantilever beams can be used. The arrangement of the hollowed-out portions and discrete piezoresistive units in the cantilever beams is similar to the structure of a single cantilever beam in this invention.

[0053] In a specific implementation, the hollowed-out portion 31 extends from the end of the cantilever beam to the root of the cantilever beam; the first discrete piezoresistive unit 5a and the second discrete piezoresistive unit 5b are located on both sides of the hollowed-out portion 31.

[0054] In a specific implementation, the hollowed-out portion 31 extends from the end of the cantilever beam to the discrete piezoresistive unit 5; the first discrete piezoresistive unit 5a and the second discrete piezoresistive unit 5b are located on the side of the hollowed-out portion 31 away from the end of the cantilever beam.

[0055] The present invention provides a high-Q dynamic probe for measuring atomic force, wherein the shape of the hollow part of the cantilever beam 3 is consistent with the shape of the cantilever beam 3, and the spatial position of the hollow part includes, but is not limited to, the following two hollowing methods.

[0056] The first hollowing method is as follows: Figure 1 As shown, the hollow section of the cantilever beam 3 extends from the end of the cantilever beam 3 to the root of the cantilever beam 3, and the lower end line of the hollow section is on the same straight line as the lower end line of the cantilever beam 3. The lower end line of the cantilever beam 3 is the boundary line between the cantilever beam 3 and the base 2. Figure 1 In this configuration, the lower end line of the cantilever beam 3 extends into the base 2, and the position of the lower end line of the cantilever beam 3 is lower than the upper end surface of the base 2. At this time, the first discrete piezoresistive unit 5a and the second discrete piezoresistive unit 5b are located on the left and right sides of the lower end of the hollowed-out portion, respectively.

[0057] The second hollowing method is as follows: Figure 3As shown, the hollow portion of the cantilever beam 3 extends from the end of the cantilever beam 3 to above the discrete piezoresistive unit 5, but does not reach the lower end line of the cantilever beam 3. At this time, the first discrete piezoresistive unit 5a and the second discrete piezoresistive unit 5b are respectively located below the hollow portion.

[0058] In a specific implementation, the second end of the connecting wire 6 is connected to the conductive liner 8 via a conductive flying wire 7.

[0059] In a specific implementation, the conductive liner 8 includes a first conductive liner 8a, a second conductive liner 8b, a third conductive liner 8c, and a fourth conductive liner 8d.

[0060] like Figure 1 and Figure 2 The conductive liner 8 is divided into four parts: the first conductive liner 8a, the second conductive liner 8b, the third conductive liner 8c, and the fourth conductive liner 8d.

[0061] In specific implementation, the connecting wire 6 includes a first connecting wire 6a, a second connecting wire 6b, a third connecting wire 6c, and a fourth connecting wire 6d;

[0062] The first discrete piezoresistive unit 5a is connected to the first conductive substrate 8a via the first connecting wire 6a;

[0063] The first discrete piezoresistive unit 5a is connected to the second conductive substrate 8b via the second connecting wire 6b;

[0064] The second discrete piezoresistive unit 5b is connected to the third conductive substrate 8c via a third connecting wire 6c.

[0065] The second discrete piezoresistive unit 5b is connected to the fourth conductive substrate 8d via the fourth connecting wire 6d.

[0066] In specific implementation, the conductive flying wire 7 includes a first conductive flying wire 7a, a second conductive flying wire 7b, a third conductive flying wire 7c, and a fourth conductive flying wire 7d;

[0067] The first connecting wire 6a is connected to the first conductive liner 8a via the first conductive flying wire 7a;

[0068] The second connecting wire 6b is connected to the second conductive substrate 8b via the second conductive flying wire 7b;

[0069] The third connecting wire 6c is connected to the third conductive liner 8c via the third conductive flying wire 7c.

[0070] The fourth connecting wire 6d is connected to the fourth conductive liner 8d via the fourth conductive flying wire 7d.

[0071] In one embodiment, the discrete piezoresistive unit 5 includes two: a first discrete piezoresistive unit 5a and a second discrete piezoresistive unit 5b; the connecting wire 6 includes four: a first connecting wire 6a, a second connecting wire 6b, a third connecting wire 6c and a fourth connecting wire 6d; the conductive flying wire 7 includes four: a first conductive flying wire 7a, a second conductive flying wire 7b, a third conductive flying wire 7c and a fourth conductive flying wire 7d; and the conductive substrate 8 includes four: a first conductive substrate 8a, a second conductive substrate 8b, a third conductive substrate 8c and a fourth conductive substrate 8d.

[0072] In specific connections, the first connecting wire 6a and the second connecting wire 6b are connected to the first discrete piezoresistive unit 5a, and the third connecting wire 6c and the fourth connecting wire 6d are connected to the second discrete piezoresistive unit 5b. The first conductive flying wire 7a, the second conductive flying wire 7b, the third conductive flying wire 7c, and the fourth conductive flying wire 7d are respectively connected to the first connecting wire 6a, the second connecting wire 6b, the third connecting wire 6c, and the fourth connecting wire 6d; the first conductive substrate 8a, the second conductive substrate 8b, the third conductive substrate 8c, and the fourth conductive substrate 8d are respectively connected to the first conductive flying wire 7a, the second conductive flying wire 7b, the third conductive flying wire 7c, and the fourth conductive flying wire 7d. The first conductive substrate 8a and the second conductive substrate 8b are electrically connected to the first discrete piezoresistive unit 5a, and the third conductive substrate 8c and the fourth conductive substrate 8d are connected to the second discrete piezoresistive unit 5b.

[0073] For cases with more than two discrete piezoresistive units, the same principle applies to setting up connecting wires, conductive fly wires, and conductive backing plates.

[0074] In a specific implementation, the needle holder 1 is provided with a groove, and the conductive liner 8 is located within the groove.

[0075] In specific implementation, the second conductive liner 8 can be attached to the surface of the needle holder 1, or one or more shallow grooves can be provided in the lower half of the needle holder 1, and the conductive liner 8 can be set in one groove as a whole, or the four parts can be set in four grooves respectively.

[0076] In specific implementation, a magnetic coating layer is provided on the needle tip 4 at the end of the cantilever beam.

[0077] In practice, the magnetic coating layer can be made of metals or alloys containing elements such as iron, cobalt, nickel, and gadolinium.

[0078] This invention discloses a high-Q dynamic probe for measuring atomic forces, which dynamically vibrates above the sample surface at its first natural frequency f0 or its second natural frequency f1, or close to its natural frequency. When the probe tip 4 approaches the sample surface, the atomic forces between the atoms of the tip 4 and the atoms of the sample surface cause a reversal in the vibration frequency of the probe cantilever beam, resulting in a frequency shift d. f The attractive force between the atoms at the probe tip and the atoms on the sample surface causes a negative frequency shift, while the repulsive force causes a positive frequency shift. The periodic vibration of the probe cantilever beam generates an electrical signal representing the periodic resistance change ΔR of the piezoresistive unit. This periodic resistance change ΔR provides the frequency shift d of the probe cantilever beam under atomic force. f Signal. The frequency shift d of the change. f The signal can provide real-time information on the atomic forces generated between the probe tip and the sample.

[0079] The present invention provides a high-Q dynamic probe for measuring atomic forces, which has the following technical features.

[0080] 1. Improves probe yield. The discrete piezoresistive unit design of this invention can significantly improve the yield of piezoresistive probes and significantly reduce the production and usage costs of piezoresistive probes.

[0081] 2. It can improve the mechanical quality factor Q of the probe. In this invention, the cantilever beam is provided with a hollow part, which can reduce energy dissipation inside the probe, thereby improving the mechanical quality factor Q of the cantilever beam. Experiments have shown that the mechanical quality factor Q of the probe of this invention can reach more than 10,000 under room temperature vacuum and more than 20,000 under low temperature vacuum, which is a significant improvement in Q value.

[0082] 3. Reduce thermal noise. In this invention, the cantilever beam is provided with a hollow part, which can reduce the energy dissipation inside the probe, thereby improving the mechanical quality factor Q of the cantilever beam, and thus reducing the thermal noise n. The calculation formula for thermal noise n is shown in the following formula (1).

[0083] (1)

[0084] In formula (1), K B It is the Boltzmann constant, Δf represents the resonant frequency f of the cantilever beam. R The displacement of the cantilever beam during vibration, where thermal represents thermal energy, T represents the temperature of the cantilever beam (in Kelvin) when the displacement Δf occurs, f0 is the first natural frequency of the cantilever beam, k is the stiffness coefficient of the cantilever beam, Q is the mechanical quality factor of the cantilever beam, and A is the value of the cantilever beam at its resonant frequency f0. RThe amplitude during vibration, π is the circumference of a circle. As can be seen from formula (1), the thermal noise n (white noise) is inversely proportional to the mechanical quality factor Q of the cantilever beam. Therefore, increasing the Q value of the cantilever beam can reduce the probe thermal noise (white noise) and improve the signal-to-noise ratio.

[0085] 4. Improve the atomic force measurement sensitivity of the probe. In this invention, the cantilever beam is provided with a hollow part, which can reduce the energy dissipation inside the probe, thereby improving the mechanical quality factor Q of the cantilever beam, and thus improving the atomic force measurement sensitivity of the probe; according to the following formula (2): In formula 2, D f D is the minimum measurable force value of the probe, used to measure the atomic force measurement sensitivity of the probe. f A smaller value indicates higher sensitivity, D f A higher value indicates lower sensitivity.

[0086] (2)

[0087] In formula (2), K B It is the Boltzmann constant, Δf represents the resonant frequency f of the cantilever beam. R The displacement of the cantilever beam during vibration, where thermal represents thermal energy, T represents the temperature of the cantilever beam (in Kelvin) when the displacement Δf occurs, k is the stiffness coefficient of the cantilever beam, B is the measurement bandwidth of the probe, and f R Q is the resonant frequency of the cantilever beam, Q is the mechanical quality factor of the cantilever beam, and A is the resonant frequency of the cantilever beam at the resonant frequency f. R The amplitude of the vibration, where π is the mathematical constant pi. The smallest measurable force D. f The mechanical quality factor Q of the cantilever beam is inversely proportional to the smaller the minimum measurable force. The smaller the minimum measurable force, the smaller the value that the probe can measure, meaning that the probe is more sensitive. Therefore, increasing the Q value of the cantilever beam can improve the force measurement sensitivity of the cantilever beam.

[0088] 5. Reduces heat generation during probe measurement. The probe of this invention connects discrete piezoresistive units end-to-end via conductive substrates, increasing the overall piezoresistive resistance. Since the power supply for the discrete piezoresistive units in this invention is a constant voltage power supply, the heat generated by the resistor W=U is reduced. 2 t / R, under constant voltage, the larger the resistance R, the smaller the heat generated per unit time, thus reducing piezoresistive heat generation, which is particularly suitable for mechanical measurements in extreme physical environments such as ultra-low temperature, ultra-high vacuum and strong magnetic field.

[0089] 6. Easy needle replacement. The probe of this invention adopts an integrated design of base and needle holder. The base 2 is fixedly mounted on the needle holder 1. In use, the experimenter only needs to use the tip of tweezers to pick up the needle holder 1. Since the needle holder 1 is relatively large, it is not easy for the tweezers to slip or fly off when holding it, making the operation convenient and quick. At the same time, it can also avoid the waste of probe resources.

[0090] 7. Expanding the application areas of the probe. The probe of this invention has a magnetic coating layer on its tip. The magnetic coating layer can be a metal or alloy containing elements such as iron, cobalt, nickel, and gadolinium, so that the probe can measure not only atomic forces but also magnetic forces, thus expanding the types of forces that can be measured.

[0091] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0092] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A high Q dynamic probe for measuring atomic forces, characterized by, The needle seat (1), the base (2), the cantilever beam (3), the needle tip (4), the discrete piezoresistive unit (5), the connecting wire (6), the conductive flying wire (7) and the conductive lining plate (8) are included. The base (2) and the conductive lining plate (8) are respectively located at both ends of the needle seat (1); the cantilever beam (3) is arranged on the base (2) and extends outward in a direction away from the conductive lining plate (8). The cantilever beam (3) is provided with a hollow part (31); one end of the cantilever beam (3) away from the needle seat (1) is a cantilever beam end, and the top of the cantilever beam end is provided with the needle tip (4). One end of the cantilever beam (3) close to the needle seat (1) is a cantilever beam root; the cantilever beam root is provided with the discrete piezoresistive unit (5); the discrete piezoresistive unit (5) includes a first discrete piezoresistive unit (5a) and a second discrete piezoresistive unit (5b); the hollow part of the cantilever beam (3) extends from the cantilever beam (3) end to the cantilever beam (3) root; the lower end line of the hollow part is on a straight line with the lower end line of the cantilever beam (3); the lower end line of the cantilever beam (3) is the junction line of the cantilever beam (3) and the base (2); the lower end line of the cantilever beam (3) extends into the base (2); the position of the lower end line of the cantilever beam (3) is lower than the upper end surface of the base (2); at this time, the first discrete piezoresistive unit (5a) and the second discrete piezoresistive unit (5b) are respectively located on the left and right sides of the lower end of the hollow part; the base (2) is provided with the connecting wire (6); the first end of the connecting wire (6) is connected with the discrete piezoresistive unit (5); the second end of the connecting wire (6) is connected with the conductive lining plate (8).

2. A high Q dynamic probe for measuring atomic forces according to claim 1, characterized in that, The first discrete piezoresistive unit (5a) and the second discrete piezoresistive unit (5b) are arranged on the same cantilever beam (3).

3. A high Q dynamic probe for measuring atomic forces according to claim 1, characterized in that, The hollow part (31) extends from the cantilever beam end to the cantilever beam root; the first discrete piezoresistive unit (5a) and the second discrete piezoresistive unit (5b) are respectively located on both sides of the hollow part (31).

4. A high Q dynamic probe for measuring atomic forces according to claim 1, characterized in that, The hollow part (31) extends from the cantilever beam end to the discrete piezoresistive unit (5); the first discrete piezoresistive unit (5a) and the second discrete piezoresistive unit (5b) are located on the side of the hollow part (31) away from the cantilever beam end.

5. A high Q dynamic probe for measuring atomic forces according to claim 1, characterized in that, The second end of the connecting wire (6) and the conductive lining plate (8) are connected through the conductive flying wire (7).

6. A high Q dynamic probe for measuring atomic forces according to claim 1, characterized in that, The conductive lining plate (8) includes a first conductive lining plate (8a), a second conductive lining plate (8b), a third conductive lining plate (8c) and a fourth conductive lining plate (8d).

7. A high Q dynamic probe for measuring atomic forces according to claim 6, characterized in that, The connecting wire (6) includes a first connecting wire (6a), a second connecting wire (6b), a third connecting wire (6c) and a fourth connecting wire (6d); The first discrete piezoresistive unit (5a) is connected with the first conductive lining plate (8a) through the first connecting wire (6a); The first discrete piezoresistive unit (5a) is connected with the second conductive lining plate (8b) through the second connecting wire (6b); The second discrete piezoresistive unit (5b) is connected with the third conductive lining plate (8c) through the third connecting wire (6c); The second discrete piezoresistance unit (5b) is connected with the fourth conductive lining (8d) through the fourth connecting wire (6d).

8. A high Q dynamic probe for measuring atomic forces according to claim 7, characterized in that, The conductive jumper (7) comprises a first conductive jumper (7a), a second conductive jumper (7b), a third conductive jumper (7c) and a fourth conductive jumper (7d). The first connecting wire (6a) is connected with the first conductive lining (8a) through the first conductive jumper (7a). The second connecting wire (6b) is connected with the second conductive lining (8b) through the second conductive jumper (7b). The third connecting wire (6c) is connected with the third conductive lining (8c) through the third conductive jumper (7c). The fourth connecting wire (6d) is connected with the fourth conductive lining (8d) through the fourth conductive jumper (7d).

9. A high Q dynamic probe for measuring atomic forces according to claim 1, characterized in that, The needle seat (1) is provided with a recess, and the conductive lining (8) is located in the recess.

10. A high Q dynamic probe for measuring atomic forces according to claim 1, characterized in that, A magnetic coating layer is arranged on the needle tip (4) at the end of the cantilever beam.

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