Cross-type double-shaft torque sensor

Abstract

The invention discloses a crossed double-shaft torque sensor, which comprises a square connecting piece connected with a nano optical cavity, and a supporting cantilever arm for supporting the square connecting piece, wherein the nano optical cavity comprises a fixed nano optical cavity wall and a movable nano optical cavity wall; the fixed nanometer optical cavity wall is used for guiding input and output light, when the movable nanometer optical cavity wall senses an external out-of-plane torque, out-of-plane displacement occurs relative to a plane, the displacement causes a gap between the movable nanometer optical cavity wall and the fixed nanometer optical cavity wall to change, so that the resonant wavelength is affected, and the resonant wavelength is changed. And finally, the corresponding force and torque are measured according to the linear relation between the wavelength and the force and torque.

Description

Technical Field

[0001] The present invention belongs to the technical field of torque measurement, and more specifically, relates to a cross-type dual-axis torque sensor. Background Art

[0002] Dual-axis torque sensors play an important role in industrial applications, especially in situations where precise control and monitoring of torque is required. With the development of micro-electromechanical systems (MEMS) technology, torque sensors have begun to move towards miniaturization to meet the needs of small torque measurement. This trend has made the application of sensors more extensive and more adaptable. In recent years, a variety of new torque sensors have appeared on the market, such as fiber-optic, wireless surface acoustic wave, magnetic sensitive, and laser-based sensors. These new sensors not only improve measurement accuracy, but also expand the application scenarios of torque sensors.

[0003] Although these new sensors, such as fiber-optic, wireless surface acoustic wave, magnetic and laser-based sensors, have made technological breakthroughs and improved measurement accuracy and wide application, they still face some technical and practical challenges.

[0004] Magnetic sensors are very sensitive to changes in the magnetic field of the environment. Any external magnetic interference may affect its measurement accuracy, which limits its application in strong magnetic field environments. Wireless surface acoustic wave sensors: They are greatly affected by environmental factors such as temperature and humidity, and can only perform at their best in a specific environment. Although new torque sensors have made significant progress in many aspects, they still have shortcomings in terms of complex installation and debugging, large environmental impact, and high cost. Future research and development should focus on solving these problems in order to better meet the needs of the market and users.

[0005] Nanobeam cavity torque sensors use advanced optical technology to measure torque by analyzing the phase change of light. This change is captured by the photodetector and converted into an electrical signal, which is then analyzed by the data processing system to obtain the torque value. Due to its high sensitivity and accuracy, nanobeam cavity torque sensors are very suitable for situations where precise torque measurement is required, and have demonstrated excellent performance in modern industrial applications. Summary of the invention

[0006] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a cross-type dual-axis torque sensor that directly measures torque through the change in the resonant wavelength of a nano-optical cavity.

[0007] To achieve the above-mentioned purpose of the invention, the present invention provides a cross-type dual-axis torque sensor, characterized in that it includes: a square connector connected to the nano-optical cavity, and a supporting cantilever arm supporting the square connector.

[0008] The object of the invention of the present invention is achieved in this way:

[0009] The invention discloses a cross-type dual-axis torque sensor, comprising: a square connector connecting a nano-optical cavity, and a cantilever support arm supporting the square connector; wherein the nano-optical cavity further comprises a fixed nano-optical cavity wall and a movable nano-optical cavity wall; the fixed nano-optical cavity wall is used to guide input and output light, and when the movable nano-optical cavity wall senses an external out-of-plane torque, it will undergo an out-of-plane displacement relative to the plane, and the displacement causes the gap between the movable nano-optical cavity wall and the fixed nano-optical cavity wall to change, thereby affecting the resonance wavelength, and finally measuring the corresponding force and torque through the linear relationship between the wavelength and the force and torque.

[0010] At the same time, the cross-type dual-axis torque sensor of the present invention also has the following beneficial effects:

[0011] (1) The cross-type dual-axis torque sensor uses a direct measurement method to measure torque, which has fewer error terms and is more accurate;

[0012] (2) Compared with the traditional torque sensor, the cross-type dual-axis torque sensor of the present invention is much smaller in size and is easier to be used in various small fields;

[0013] (3) Since the nano-beam cavity of the present invention adopts optical principles for measurement, it can detect extremely small phase changes, so it is extremely sensitive to torque changes and can achieve very high measurement accuracy;

[0014] (4) The nano-beam cavity of the present invention can work normally in harsh environments such as high temperature and high pressure, and will not lose accuracy due to environmental changes. It is suitable for many fields ranging from automobile manufacturing to aerospace and mechanical processing, and performs particularly well in equipment testing with high precision requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 1 is a structural diagram of a cross-type dual-axis torque sensor of the present invention, wherein (a) is a top view and (b) is a left view;

[0016] Figure 2 Schematic diagram of the cross-type dual-axis torque sensor before and after applying horizontal torque, where (a) is a top view and (b) is a left view;

[0017] Figure 3 Schematic diagram of the cross-type dual-axis torque sensor before and after applying vertical torque, where (a) is a top view and (b) is a left view;

[0018] Figure 4 is a schematic diagram of a mirror pattern;

[0019] Figure 5Schematic diagram of the manufacturing process of the nano-optical cavity wall. DETAILED DESCRIPTION

[0020] The specific implementation of the present invention is described below in conjunction with the accompanying drawings so that those skilled in the art can better understand the present invention. It should be noted that in the following description, when the detailed description of known functions and designs may dilute the main content of the present invention, these descriptions will be omitted here.

[0021] Example

[0022] Figure 1 This is a structural diagram of a cross-type dual-axis torque sensor of the present invention.

[0023] In this embodiment, if Figure 1 As shown in (a), a cross-type dual-axis torque sensor of the present invention includes: a square connector connected to a nano-optical cavity, and a supporting cantilever arm supporting the square connector.

[0024] The nano-optical cavity includes two groups, which are connected vertically by a square connector and symmetrically connected around the four sides of the square connector. Figure 1 As shown in (b), after the two groups of nano-optical cavities are symmetrically connected by the square connector e, the two groups of nano-optical cavities are divided into four sections, denoted as a, b, c, and d. The length of each section is about 5um and the width is 600nm. The side length of the square connector e located in the center is 1800nm.

[0025] like Figure 1 As shown in (b), the nano-optical cavity includes two layers of nano-optical cavity walls with the same structure, wherein the upper layer is a movable nano-optical cavity wall and the lower layer is a fixed nano-optical cavity wall;

[0026] Among them, the fixed nano-optical cavity wall is used to guide the input and output of light; the movable nano-optical cavity wall moves up and down through physical induction, thereby changing the gap with the fixed nano-optical cavity wall, thereby changing the resonant wavelength of the nano-optical cavity.

[0027] In this embodiment, the movement of the movable nano-optical cavity wall can be induced by various physical measurements, such as applying a torque, such as Figure 2 As shown in (a), when the horizontal torque M is felt, the upper horizontal nano-optical cavity wall rotates, as shown in Figure 2As shown in (b), the vertical wall of the nano-optical cavity is tilted, with one end close to the lower layer and the other end away from the lower layer, that is: if the gap between the nano-optical cavity wall a and the groove of the lower fixed nano-optical cavity becomes smaller, then the gap between the nano-optical cavity wall b and the lower fixed nano-optical cavity becomes larger. In this way, the mechanical movement of the movable nano-optical cavity wall changes the gap size between the cavity walls, thereby changing the resonant wavelength of the nano-optical cavity. Finally, the displacement of the movable nano-optical cavity wall can be calculated by measuring the change in the resonant wavelength, thereby measuring the magnitude of the torque.

[0028] For example: Figure 2 As shown in (b), the initial gap between the movable nano-optical cavity wall 1 and the fixed nano-optical cavity wall 2 is 300nm. The relationship between the groove gap of the nano-optical cavity and the resonance wavelength is

[0029] m*λ=2n c L

[0030] Where m is the diffraction order, λ is the resonance wavelength, and n c is the effective refractive index, and L is the slot gap of the nano-optical cavity.

[0031] When the torque is felt, the resonant wavelength will change by Δλ, which can be substituted into the formula m*Δλ=2n c ΔL, we can get the size of ΔL. Finally, based on the direct linear relationship between torque and ΔL, we can calculate the size of the torque.

[0032] Similarly, if Figure 3 As shown, when subjected to a torque M in the vertical direction, the magnitude of the torque can be measured by the same calculation method.

[0033] In this embodiment, if Figure 4 As shown in the figure, the nano-optical cavity wall is symmetrically arranged with the central axis, and the hole shape of the mirror pattern gradually changes from a circle to an ellipse. The spacing between two adjacent holes is the same. Each hole on the mirror pattern is similar to a gap, and the length from the two ends to the inside is n. m The series of holes are collectively called external holes, which form a group of reflectors; the length from the center point to both ends is n c The series of holes are collectively called inner holes, which form an optical cavity that supports the optical mode.

[0034] Figure 5 Schematic diagram of the manufacturing process of the nano-optical cavity wall.

[0035] In this embodiment, if Figure 5 As shown, the nano-optical cavity wall is fabricated in a 400nm thick SiN layer on top of a 500μm silicon layer. The SBC device is fabricated using a 1cm 2The chips are made of silicon-on-insulator (SOI) chips. They are cut from 6-inch diameter wafers with a 3-micron-thick silicon dioxide (SiO2) layer and a 220-nanometer-thick silicon (Si) top layer. The purpose of the manufacturing cycle is to define the pattern of our devices on the silicon chip. The standard semiconductor manufacturing process for silicon is followed, with seven major steps: cleaning, resist coating (ZEP 520A), first layer (Si) electron beam lithography, cooling treatment, silicon etching (transfer of the pattern to the silicon layer), heated cleaning machine-PG cleaning, and undercutting (etching the SiO_2 using HF to release the device).

[0036] The first step is a standard cleaning procedure that uses sulfuric acid and hydrogen peroxide in one reaction to clean all organic compounds from the chip. A 300-400nm thick orthochromatic resist (ZEP 520A) is spun on the chip and then cured by heat. The device pattern is written on the resist using electron beam lithography. This is followed by a cold development process to carefully remove the exposed resist. To transfer the pattern from the resist to the silicon device layer, a reactive ion etching step using fluorine chemistry is performed. Finally, after the remaining resist is cleaned with heated Remover-PG, a wet chemical stripping process using hydrofluoric acid (HF) etches the exposed silicon dioxide and releases the silicon device.

[0037] Although the above describes the illustrative specific embodiments of the present invention to facilitate those skilled in the art to understand the present invention, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concept of the present invention are protected.

Claims

1. A cross-type dual-axis torque sensor, characterized in that: include: A square connector connecting the nano-optical cavity and a supporting cantilever arm supporting the square connector.

2. A cross-type dual-axis torque sensor according to claim 1, characterized in that: The nano-optical cavity comprises two groups, and the two groups of nano-optical cavities are vertically connected through a square connecting piece, and are symmetrically connected around the square connecting piece.

3. A cross-type dual-axis torque sensor according to claim 1, characterized in that: The nano-optical cavity comprises two layers of nano-optical cavity walls with the same structure, wherein the upper layer is a movable nano-optical cavity wall and the lower layer is a fixed nano-optical cavity wall; Among them, the fixed nano-optical cavity wall is used to guide the input and output of light; the movable nano-optical cavity wall moves up and down through physical induction, thereby changing the gap with the fixed nano-optical cavity wall, thereby changing the resonant wavelength of the nano-optical cavity.

4. A cross-type dual-axis torque sensor according to claim 1, characterized in that: The nano-optical cavity wall is symmetrically provided with a mirror pattern with the central axis as the center axis. The hole shape of the mirror pattern gradually changes from a circle to an ellipse. The spacing between two adjacent holes is the same. Each hole on the mirror pattern is similar to a gap. The length from both ends to the inside is n. m The series of holes are collectively called external holes, which form a set of reflectors; the length from the center point to both ends is n c The series of holes are collectively called inner holes, which form an optical cavity that supports the optical mode.

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