Fluidic angular acceleration sensor, production mold and production method

Abstract

The application discloses a fluid type acceleration sensor, a preparation mold and a preparation method. The fluid type angular acceleration sensor comprises a shell, three semi-canal and a container connecting the semi-canal, a channel for liquid circulation is arranged in the semi-canal, the container has a cavity, the cavity is communicated with the channel of each semi-canal to jointly form a closed fluid cavity, wherein the central axis of the three semi-canal respectively bends and extends in three planes, the three planes pass through an original point and are perpendicular to each other, three ampulla caps are correspondingly arranged in the semi-canal, the edge of the ampulla cap is connected with the semi-canal to close the channel, the ampulla cap can be deformed by being pushed by the liquid in the channel, and three strain gauges are correspondingly arranged in the ampulla cap and are configured to follow the deformation of the ampulla cap and convert the deformation into an electric signal output. The fluid type acceleration sensor, the preparation mold and the preparation method can provide more accurate and reliable angular acceleration signals.

Description

Technical Field

[0001] This invention relates to the field of acceleration sensor technology, and more particularly to a fluid acceleration sensor, a fabrication mold, and a fabrication method. Background Technology

[0002] In extreme application scenarios such as the deep sea, traditional inertial measurement units (IMUs) have significant limitations in attitude sensing. Specifically, gyroscopes are prone to accuracy degradation under high pressure and low temperature environments, magnetic field anomalies caused by the complex mineral distribution on the seabed can significantly interfere with magnetic sensors, and the complex and variable seawater current conditions further affect the stability and reliability of the attitude sensing system.

[0003] One technical solution provides a fluid-type accelerometer that connects multiple piezoelectric fibers in parallel to form a single unit. One end of the fiber is fixed to a base, while the other end remains free, creating a cantilever beam structure. This entire unit is embedded within a semicircular tube, with the free end's metal core immersed in an insulating liquid. These fibers are arranged in three spatial coordinate systems to sense rotation in different directions. When the entire device is subjected to rotation, the fibers in the three directions undergo different deformations. Due to the different electrode positions, the charges or voltages generated on the electrodes differ. By analyzing the polarity and values ​​of the three fibers using a charge amplifier and processing unit, the direction and magnitude of the multidimensional rotational acceleration can be determined.

[0004] The free-end metal core is propelled by the flow of insulating fluid to oscillate within the pseudo-semicircular tube, thereby achieving deformation and generating electrical signals. However, the oscillation has a significant hysteresis, and the return to the original position after oscillation is relatively slow, resulting in its inability to provide feedback on real-time changes in rotational acceleration. Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a fluid-type angular acceleration sensor that can provide more accurate and reliable angular acceleration signals.

[0006] The present invention also proposes a method for fabricating a fluid angular acceleration sensor.

[0007] The present invention also proposes a fabrication mold suitable for the fabrication method of fluid angular acceleration sensors.

[0008] A fluid angular acceleration sensor according to a first aspect of the present invention includes: The housing includes three semicircular tubes and a container connecting each of the semicircular tubes. Each semicircular tube has a channel for liquid flow. The container has a cavity that communicates with the channel of each semicircular tube to form a closed fluid cavity. The central axes of the three semicircular tubes extend in three planes that pass through an origin and are perpendicular to each other. Three ampulla caps are correspondingly disposed in each of the semicircular canals. The edges of the ampulla caps are connected to the semicircular canals to close the channels. The ampulla caps can be deformed by the liquid within the channels. Three strain gauges are respectively disposed on each of the ampulla caps, configured to follow the deformation of the ampulla caps, and convert the deformation into an electrical signal output.

[0009] The fluid angular acceleration sensor according to embodiments of the present invention has at least the following beneficial effects: By placing ampulla caps within each semicircular canal, the ampulla caps, which enclose the channels, are deformed by the liquid within the channels. Strain gauges are mounted on the ampulla caps, which deform along with the caps and convert the deformation into electrical signals. When a semicircular canal rotates within its corresponding plane, the liquid exhibits inertial hysteresis relative to that semicircular canal, creating a pressure gradient that acts on the ampulla cap, causing significant deformation. This results in deformation of the corresponding strain gauge and the output of an electrical signal. The liquid in the other two semicircular canals has a smaller effect on the ampulla caps. This allows for the component sensing and approximate decoupling of angular acceleration signals from three mutually orthogonal rotational axes, thereby obtaining attitude sensing signals. Because the edges of the ampulla caps connect to the semicircular canals and enclose the channels, the edges of the ampulla caps do not shift with the liquid flow. Furthermore, since the ampulla caps enclose the channels, all liquid pressure acts on the surface of the ampulla caps. This results in rapid deformation and high sensitivity of the ampulla caps and strain gauges, providing more accurate and reliable angular acceleration signals. This supports the autonomous perception and navigation of soft robots in extreme environments such as the deep sea.

[0010] According to some embodiments of the present invention, the portion of the semicircular tube away from the container is a flank, the inner diameter of the flank is larger than the inner diameter of the remaining portion of the semicircular tube, and the flank cap is disposed on the flank.

[0011] According to some embodiments of the present invention, the channel inside the ampulla gradually expands from both ends toward the middle, and the ampulla cap is disposed in the middle of the ampulla.

[0012] According to some embodiments of the present invention, the ampulla expands radially outward.

[0013] According to some embodiments of the present invention, the side of the vessel opposite to the container has an inwardly protruding ridge; One end of the strain gauge is connected to the ampulla ridge, and the other end of the strain gauge, away from the ampulla ridge, is located in the geometric center region of the ampulla cap.

[0014] According to some embodiments of the present invention, the ampulla has a through hole on the side opposite to the container; the strain gauge is opposite to the through hole along the radial direction of the semicircular tube.

[0015] According to some embodiments of the present invention, the ampulla has a through hole on the side opposite to the container; the ampulla cap is opposite to the through hole along the radial direction of the semicircular tube.

[0016] According to some embodiments of the present invention, the strain gauge is disposed inside the ampulla cap.

[0017] A method for fabricating the fluid angular acceleration sensor described in the above embodiments according to a second aspect of the present invention includes: Prepare the shell; The strain gauges are implanted into the semicircular tubes of the housing; Precursor liquid is injected into the housing and solidified at the strain gauge to form a funnel cap.

[0018] According to some embodiments of the present invention, the semicircular tubes of the housing have through holes; The step of injecting precursor liquid into the housing and solidifying the precursor liquid at the strain gauge to form a funnel cap includes: Inject the precursor liquid into the shell, and let ultraviolet light irradiate the precursor liquid in the semicircular tube that is radially opposite to the through hole through the through hole, and maintain it for a first preset time to obtain a semi-finished membrane. The precursor solution is discharged, and ultraviolet light is irradiated onto the semi-finished membrane through the through-hole and maintained for a second preset time to obtain the ampulla cap.

[0019] According to some embodiments of the present invention, the precursor solution includes a photoinitiator, a crosslinking agent, choline chloride, and acrylic acid; The preparation method of the precursor solution is as follows: Obtain 8.5 mL–9.5 mL of acrylic acid and 10.0 g–11.5 g of choline chloride, heat to the first preset temperature and stir continuously to obtain a deep eutectic solvent; Cool the eutectic solvent to a second preset temperature, add 0.008 g–0.015 g of crosslinking agent, 0.015 g–0.025 g of photoinitiator, and 65 mL–75 mL of deionized water and stir continuously to obtain the precursor solution.

[0020] A fabrication mold according to a third aspect of the present invention is applicable to the fabrication method of the fluid angular acceleration sensor described in the above embodiments, the fabrication mold comprising: Bottom cover; The upper cover, which fits with the bottom cover, encloses an assembly cavity for fixing the housing or the semicircular tube. At least one of the upper cover and the bottom cover has a light-transmitting hole that communicates with the assembly cavity and is positioned opposite a through hole on the semicircular tube. The lamp holder has a mounting position for mounting a UV lamp, the mounting position being used to align the light-emitting side of the UV lamp with the light-transmitting hole.

[0021] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic diagram of the structure of the fluid angular acceleration sensor according to an embodiment of the present invention; Figure 2 This is a partial structural diagram of the semicircular tube of the fluid angular acceleration sensor according to an embodiment of the present invention; Figure 3 This is a schematic cross-sectional view of the semicircular tube of the fluid angular acceleration sensor according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the bottom cover of the mold according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the bottom cover of the mold according to an embodiment of the present invention.

[0023] Figure label: 100. Shell; 110. Semicircular tubes; 110a. Channel; 111. Ampulla; 1111. Ampulla crest; 111a. Through hole; 110b. Injection hole; 120. Container; 200. Ampulla cap; 300. Strain gauge; 10. Bottom cover; 20. Top cover; 201. Light-transmitting hole. Detailed Implementation

[0024] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0026] In the description of the embodiments of this application, the technical terms "first," "second," "third," etc., are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0027] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0028] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects are in an "or" relationship.

[0029] In the description of the embodiments of this application, the technical terms "top", "bottom", "upper", "lower", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0030] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0031] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical term "contact" should be interpreted broadly, and can be direct contact, contact through an intermediate medium layer, contact between two contacting parties with substantially no interaction force, or contact between two contacting parties with interaction force.

[0032] Please refer to Figures 1-3 This application provides a fluid angular acceleration sensor with a biomimetic structure inspired by the vestibular system, including a housing 100, three ampulla caps 200 and three strain gauges 300.

[0033] The housing 100 includes three semicircular tubes 110 and a container 120 connecting the semicircular tubes 110. Each semicircular tube 110 has a channel 110a for liquid flow. The container 120 has a cavity that communicates with the channel 110a of each semicircular tube 110, together forming a closed fluid cavity. The housing 100 has an injection hole 110b for liquid injection, which can be located on at least one semicircular tube 110. The liquid can be deionized water, filling the entire annular channel. As a working medium for biomimetic endolymph, the liquid has suitable density and viscosity, and can generate inertial relative flow consistent with that of a biological organism under angular acceleration.

[0034] The central axes of the three semicircular canals 110 extend and bend in three planes, which pass through an origin and are mutually perpendicular. That is, the three planes are the three reference planes of the XYZ Cartesian coordinate system. The central axis of each semicircular canal 110 extends and bends in its respective plane, allowing it to respond to the angular acceleration signal of a rotation axis. The three semicircular canals 110 are the superior semicircular canal 110, the posterior semicircular canal 110, and the horizontal semicircular canal 110, respectively, sensing rotational motion in the sagittal, frontal, and horizontal planes. For example, the superior, posterior, and horizontal semicircular canals 110 have essentially the same shape and size.

[0035] Three ampulla caps 200 are correspondingly disposed on each semicircular tube 110. The edges of the ampulla caps 200 are connected to the semicircular tubes 110 to close the channel 110a. The ampulla caps 200 can be deformed by the liquid in the channel 110a. Three strain gauges 300 are correspondingly disposed on the ampulla caps 200 and are configured to follow the deformation of the ampulla caps 200, converting the deformation into an electrical signal output. Specifically, the strain gauges 300 bend accordingly, and their resistance values ​​change. The two pins of the strain gauges 300 are respectively connected to a Wheatstone bridge circuit. The output of the bridge is connected to a data acquisition card, which converts the analog voltage signal into a normalized digital signal through analog-to-digital conversion (A / D) and transmits it to the host computer for processing, realizing real-time sensing and measurement of angular acceleration.

[0036] In the above embodiment, when the semicircular tube 110 rotates in the corresponding plane, the liquid exhibits inertial hysteresis relative to the semicircular tube 110, forming a pressure gradient that acts on the ampulla cap 200, causing significant deformation of the corresponding ampulla cap 200. This causes the corresponding strain gauge 300 to deform and output an electrical signal. The liquid in the other two semicircular tubes 110 has a smaller effect on the ampulla cap 200. This achieves component sensing and approximate decoupling of the angular acceleration signals from three mutually orthogonal rotation axes, thereby obtaining an attitude sensing signal. Since the edge of the ampulla cap 200 is connected to the semicircular tube 110 and closes the aforementioned channel 110a, the edge of the ampulla cap 200 will not displace with the liquid flow. Furthermore, because the ampulla cap 200 closes the channel 110a, all liquid pressure acts on the surface of the ampulla cap 200. This results in rapid deformation and high sensitivity of the ampulla cap 200 and strain gauge 300, providing more accurate and reliable angular acceleration signals and supporting autonomous perception and navigation of soft robots in extreme environments such as the deep sea.

[0037] In some embodiments, the section of the semicircular tube 110 away from the container 120 is called the ampulla 111, and the inner diameter of the ampulla 111 is larger than the inner diameter of the remaining sections of the semicircular tube 110. The ampulla cap 200 is disposed on the ampulla 111. The enlarged diameter structure of the ampulla 111 increases the area of ​​the ampulla cap 200, making the deformation of the ampulla cap 200 more significant under the same angular acceleration. This results in a more obvious change in the electrical signal obtained by the strain gauge 300, thereby improving the reliability of the output signal.

[0038] For example, the ampulla 111 expands radially outward, increasing the maximum inner diameter of the expanded ampulla 111, thereby accommodating a larger area of ​​the ampulla cap 200. Each semicircular tube 110 is provided with two injection holes 110b, which are distributed axially on both sides of the ampulla 111.

[0039] In some embodiments, the channel 110a within the ampulla 111 gradually expands from both ends toward the middle, and the ampulla cap 200 is located in the middle of the ampulla 111. Compared to abrupt expansion, gradual expansion allows the liquid to diffuse and flow outward more gently within the ampulla 111, thereby providing a more uniform force to the ampulla cap 200 and improving the stability and reliability of the output signal.

[0040] In some embodiments, the ampulla cap 200 is arranged radially along the semicircular tube 110. This allows its deformation direction to align with the direction of fluid action, thereby maximizing the conversion of fluid pressure into film deformation and reducing energy loss. When the ampulla cap 200 is positioned in the ampulla 111, the aforementioned radial arrangement further enhances its ability to deform the fluid pressure within the ampulla 111.

[0041] Please refer to Figure 2 and Figure 3In some embodiments, the ampulla 111 has an inwardly protruding ampulla ridge 1111 on the side opposite to the container 120. The edge of the ampulla cap 200 is partially connected to the ampulla ridge 1111, while the remaining edge is connected to the non-ridged inner wall of the ampulla 111.

[0042] One end of the strain gauge 300 is connected to the ampulla ridge 1111, and the other end of the strain gauge 300, away from the ampulla ridge 1111, is located in the geometric center region of the ampulla cap 200. The ampulla ridge 1111, as a rigid structure, effectively fixes one end of the strain gauge 300, thus limiting its displacement. Figure 3 In this design, the ampulla cap 200 is disposed within the aforementioned channel 110a, and its shape is the cross-sectional shape of the channel 110a. The geometric center region of the ampulla cap 200 is the geometric center region of the cross-section of the channel 110a. The geometric center region of the ampulla cap 200 is the position where the deformation along the axial direction of the semicircular tube 110 is most significant. This allows the end of the strain gauge 300 away from the ampulla ridge 1111 to be located in the geometric center region of the ampulla cap 200, maximizing the deformation of the strain gauge 300 and thus significantly improving the accuracy of the output electrical signal.

[0043] To facilitate the installation of the strain gauge 300, in some embodiments, the ampulla 111 has a through hole 111a on the side opposite to the container 120. The through hole 111a penetrates the ridge of the ampulla 1111, and the strain gauge 300 is inserted into the semicircular tube 110 through the through hole 111a. Along the radial direction of the semicircular tube 110, the strain gauge 300 is opposite to the through hole 111a to facilitate the installation of the strain gauge 300.

[0044] One end of the strain gauge 300 is fixed to the through hole 111a by encapsulation with DuPont adhesive. DuPont adhesive has good adhesion and stability, which can effectively protect the conductive ink layer from hydrogel and liquid environment corrosion and improve the overall mechanical stability.

[0045] The strain gauge 300 is embedded in the ampulla cap 200, forming a continuous flexible coupling interface between the strain gauge 300 and the ampulla cap 200. This reduces local stress concentration caused by sudden changes in stiffness, ensures that the bending of the ampulla cap 200 can be completely and uniformly transmitted to the strain gauge 300, and improves the linearity and measurement accuracy of the bending signal.

[0046] Among them, the through hole 111a is a rectangular through hole 111a, and the long side of the rectangular through hole 111a extends circumferentially along the semicircular tube 110.

[0047] To facilitate the molding of the ampullary cap 200, in some embodiments, the ampullary cap 200 is positioned opposite the through-hole 111a along the radial direction of the semicircular canal 110. Specifically, during the fabrication of the ampullary cap 200, a precursor liquid is injected into the housing 100. Ultraviolet light irradiates the precursor liquid within the semicircular canal 110 through the through-hole 111a, causing the radially distributed precursor liquid on one side of the through-hole 111a to solidify, thereby forming the ampullary cap 200. Positioning the ampullary cap 200 opposite the through-hole 111a radially ensures that ultraviolet light can form a complete and sealed ampullary cap 200 that seals the channel 110a of the semicircular canal 110.

[0048] In some embodiments, the strain gauge 300 is disposed within the ampulla cap 200. In this way, the strain gauge 300 and the ampulla cap 200 do not require additional connecting structures. The deformation of the ampulla cap 200 can be directly and losslessly transmitted to the strain gauge 300. At the same time, the deformation of the strain gauge 300 can fully reflect the true strain state of the ampulla cap 200 and will not be affected by additional connecting structures.

[0049] Since the strain gauge 300 is placed inside the ampulla cap 200, there are ampulla caps 200 distributed on both sides of the strain gauge 300. During the molding process of the ampulla cap 200, when ultraviolet light is irradiated through the through hole 111a, part of the precursor liquid on both sides of the strain gauge 300 is solidified, thereby firmly embedding the strain gauge 300 into the inside of the ampulla cap 200.

[0050] This application also provides a method for fabricating a fluid angular acceleration sensor, comprising: S100, Prepare the shell 100.

[0051] The shell 100 is made of photocurable resin. The three semicircular tubes 110 and the container 120 of the shell 100 can be integrally formed by photocurable printing, which can achieve high-precision forming of complex three-dimensional annular pipes while ensuring structural strength. This ensures that the cross-sectional dimensions of the semicircular tubes 110 are consistent and the shape and position of the ampulla ridges are accurate, thereby ensuring the biomimetic geometric relationship between the flow characteristics of the liquid in the pipe and the local expansion structure of the ampulla 111.

[0052] S200, The strain gauge 300 is implanted into the semicircular tube 110 of the housing 100.

[0053] S300, Inject precursor liquid into housing 100 and solidify precursor liquid at strain gauge 300 to form ampulla cap 200.

[0054] One approach is to place each strain gauge 300 within its corresponding semicircular tube 110, and then form all the ampulla caps 200 in one step, thus improving process efficiency. Alternatively, a single strain gauge 300 can be placed within its corresponding semicircular tube 110, and then the corresponding precursor liquid can be cured to form the ampulla cap 200. This process can be repeated multiple times to complete the fabrication of all the ampulla caps 200.

[0055] The strain gauge 300 is prepared by screen printing carbon nanotube ink on a PI film substrate. Carbon nanotubes have high sensitivity and can produce significant resistance changes under slight bending. The PI film substrate has good fatigue resistance, which enables the strain gauge 300 to maintain stable performance during multiple cyclic deformations.

[0056] In the above embodiments, the precursor liquid has a modulus similar to that of the biological ampullary cap 200. The bending deformation produced under pressure gradient force can be cured by ultraviolet light to obtain a flexible film of uniform thickness, ensuring a stable and consistent mechanical response of the ampullary cap 200. The ampullary cap 200 is directly formed within the semicircular canal 110 after curing with the precursor liquid, thus solving the problem of difficult connection between the ampullary cap 200 and the semicircular canal 110, and resulting in a more robust and reliable connection.

[0057] In some embodiments, the semicircular tubes 110 of the housing 100 have through holes 111a.

[0058] The steps in S300 include: S310. Inject a precursor liquid into the housing 100, and allow ultraviolet light to irradiate the precursor liquid in the semicircular tube 110 that is radially opposite to the through hole 111a through the through hole 111a, and maintain this for a first preset time to obtain a semi-finished film. The precursor liquid solidifies after being irradiated by ultraviolet light to form a semi-finished film, and the semi-finished film covers the strain gauge 300.

[0059] S320. Discharge the precursor liquid, allow ultraviolet light to irradiate the semi-finished film through the through hole 111a, and maintain for a second preset time to obtain the ampulla cap 200. By discharging the uncured precursor liquid and then subjecting the semi-finished film to a second ultraviolet irradiation, the reliability of the ampulla cap 200 can be further improved, while avoiding the impact of uncured precursor liquid residue on the performance of the ampulla cap 200.

[0060] The ultraviolet light is emitted by an ultraviolet lamp with a wavelength of 365 nm. For example, the first preset duration is 1.5–3 min, and the second preset duration is 8–15 min.

[0061] In some embodiments, the precursor solution includes a photoinitiator, a crosslinking agent, choline chloride, and acrylic acid. The photoinitiator is Irgacure 2959 (I2959), and the crosslinking agent is N,N′-methylenebisacrylamide (MBA).

[0062] The preparation method of the precursor solution is as follows: S01. Obtain 8.5 mL–9.5 mL of acrylic acid and 10.0 g–11.5 g of choline chloride, heat to the first preset temperature and stir continuously to obtain a deep eutectic solvent.

[0063] S02. Cool the deep eutectic solvent to the second preset temperature, add 0.008g-0.015g crosslinking agent, 0.015g-0.025g photoinitiator and 65mL-75mL deionized water and stir continuously to obtain the precursor solution.

[0064] In step S01, acrylic acid is used as a hydrogen bond donor and choline chloride as a hydrogen bond acceptor. The first preset temperature is 75°C–85°C. Both are heated at 75°C–85°C and stirred continuously for 2–3 hours to promote hydrogen bond formation and obtain a homogeneous, transparent, and well-flowing eutectic solvent. The molar ratio of acrylic acid to choline chloride is controlled within the range of 1:(6.0–7.0).

[0065] For example, 9.06 mL of acrylic acid liquid and 10.96 g of choline chloride are weighed and heated at 80 °C for 2.5 h with continuous stirring, wherein the molar ratio of acrylic acid to choline chloride is 1:6.6.

[0066] In step S02, the second preset temperature is 45°C–60°C. 0.008g–0.015g of crosslinking agent and 0.015g–0.025g of photoinitiator are added to the eutectic solvent, which has been cooled to 45°C–60°C. The mixture is stirred for 10–20 min to ensure complete dissolution and uniform dispersion. Then, 65–75 mL of deionized water is added, and stirring continues for another 10–20 min to obtain the precursor solution. The volume ratio of the eutectic solvent to deionized water is (1.5–2.5):(7.5–8.5).

[0067] For example, at a second preset temperature of 60°C, 0.01 g of N,N′-methylenebisacrylamide (MBA) as a crosslinking agent and 0.018 g of Irgacure 2959 (I2959) as a photoinitiator are added to a deep eutectic solvent cooled to 60°C, and stirred for 15 min. Then, 70.4 mL of deionized water is added, and stirring continues for 15 min to obtain a hydrogel precursor solution with a deep eutectic solvent:deionized water volume ratio of 2:8.

[0068] To further optimize bubble control and system homogeneity, after step S02, the precursor solution is transferred to a gas washing bottle (approximately 100 mL–250 mL in volume) and placed in a vacuum chamber equipped with a glove box for vacuuming. The vacuum level can be controlled within... 0.08 to After the negative pressure reaches equilibrium, maintain a pressure of 0.10 MPa (or <10 kPa absolute pressure) for 8–15 minutes to fully remove dissolved gases. After vacuum treatment, introduce nitrogen into the vacuum chamber to restore atmospheric pressure. Open the vacuum chamber from the nitrogen side of the glove box, remove the washing bottle, and immediately replace the rubber stopper. Then, introduce nitrogen into the long glass tube of the washing bottle, slowly open the flow valve, and gradually increase the flow rate until the liquid is just barely prevented from being blown out (recommended flow rate 20 mL / min–80 mL / min). Continue nitrogen flow for 15–30 minutes to further remove dissolved oxygen from the solution and reduce oxygen inhibition during subsequent free radical polymerization. For example, maintain the negative pressure for 10 minutes after equilibrium is reached, and continue nitrogen flow for 20 minutes.

[0069] In step S300, the precursor liquid is slowly drawn out using a syringe and injected into the prefabricated housing 100 at a uniform speed to avoid air bubbles from entering.

[0070] In step S310, the housing 100 is embedded into the mold, with the light-transmitting hole 201 of the mold aligned with the through hole 111a on the housing 100. The light-transmitting hole 201 is an elongated structure with a width of 1 mm–2 mm. The light intensity is controlled at 80–120 mW / cm², and curing is performed under this light condition for 1.5–3 min. For example, the width of the light-transmitting hole 201 is 2 mm. The light intensity is controlled at 100 mW / cm², and curing is performed under this light condition for 2 min.

[0071] In step S320, the shell 100 is removed from the mold, the precursor liquid is drained, and then photocuring is performed for 8–15 minutes to ensure that the crosslinking reaction is fully completed and to improve structural stability. In step S320 above, the shell 100 and the semi-finished film do not need to be placed back into the mold.

[0072] Please refer to Figures 4-5 This application also provides a preparation mold, applicable to the preparation method of a fluid angular acceleration sensor. The preparation mold includes a bottom cover 10, an upper cover 20, and a lamp holder.

[0073] The bottom cover 10 and the top cover 20 fit together to form an assembly cavity for fixing the housing 100 or the semicircular tube 110. Figure 4 and Figure 5 In the middle, the bottom cover 10 and the top cover 20 together form an assembly cavity for fixing the semicircular tube 110. When selected Figure 4 and Figure 5 When constructing the bottom cover 10 and top cover 20 structure, three semicircular tubes 110 need to be prepared and then combined with the container 120 to obtain the shell 100.

[0074] At least one of the upper cover 20 and the bottom cover 10 has a light-transmitting hole 201, which communicates with the assembly cavity and is used to align with the through hole 111a on the semicircular tube 110. That is, the upper cover 20 has a light-transmitting hole 201, or the bottom cover 10 has a light-transmitting hole 201, or both the upper cover 20 and the bottom cover 10 have light-transmitting holes 201.

[0075] The lamp holder has a mounting position for mounting a UV lamp, which aligns the light-emitting side of the UV lamp with the light-transmitting hole 201, thereby ensuring that UV light enters the through-hole 111a through the light-transmitting hole 201 to solidify the precursor liquid within the housing 100 to form the ampulla cap 200. Specifically, when both the upper cover 20 and the bottom cover 10 have light-transmitting holes 201, there are two lamp holders, one located on the side of the upper cover 20 facing away from the bottom cover 10, and the other on the side of the bottom cover 10 facing away from the upper cover 20. Correspondingly, the housing 100 has two through-holes 111a, which are radially opposite each other, with each through-hole 111a corresponding to one light-transmitting hole 201. The luminous intensity of the UV lamp on one lamp holder is 100 mW / cm², and the luminous intensity of the UV lamp on the other lamp holder is 100 mW / cm².

[0076] The above embodiments are merely illustrative of the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and all should be covered within the scope of the specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of protection.

Claims

1. A fluid-type angular acceleration sensor, characterized in that, include: The housing includes three semicircular tubes and a container connecting each of the semicircular tubes. Each semicircular tube has a channel for liquid flow. The container has a cavity that communicates with the channel of each semicircular tube to form a closed fluid cavity. The central axes of the three semicircular tubes extend in three planes that pass through an origin and are perpendicular to each other. Three ampulla caps are respectively disposed on each of the semicircular tubes. The edge of the ampulla cap is connected to the semicircular tube to close the channel. The ampulla cap can be deformed by the liquid in the channel. as well as Three strain gauges are respectively disposed on each of the ampulla caps, configured to follow the deformation of the ampulla caps, and convert the deformation into an electrical signal output.

2. The fluid angular acceleration sensor according to claim 1, characterized in that, The portion of the semicircular tube away from the container is called the ampulla, and the inner diameter of the ampulla is larger than the inner diameter of the remaining portion of the semicircular tube. The ampulla cap is disposed on the ampulla.

3. The fluid angular acceleration sensor according to claim 2, characterized in that, The channel inside the ampulla gradually expands from both ends toward the middle, and the ampulla cap is located in the middle of the ampulla; And / or, The ampulla expands radially outward.

4. The fluid angular acceleration sensor according to claim 2, characterized in that, The side of the vessel opposite to the container has an inwardly protruding ridge; One end of the strain gauge is connected to the ampulla ridge, and the other end of the strain gauge, away from the ampulla ridge, is located in the geometric center region of the ampulla cap.

5. The fluid angular acceleration sensor according to claim 2, characterized in that, The side of the vessel opposite to the container has a through hole; Along the radial direction of the semicircular tube, the strain gauge is opposite to the through hole; And / or, Along the radial direction of the semicircular tube, the ampulla cap is opposite the through hole.

6. The fluid angular acceleration sensor according to claim 1, characterized in that, The strain gauge is disposed inside the ampulla cap.

7. A preparation method, characterized in that, For fabricating a fluid angular acceleration sensor as described in any one of claims 1-6, comprising: Prepare the shell; The strain gauges are implanted into the semicircular tubes of the housing; Precursor liquid is injected into the housing and solidified at the strain gauge to form a funnel cap.

8. The method for fabricating a fluid angular acceleration sensor according to claim 7, characterized in that, The semicircular tubes of the housing have through holes; The step of injecting precursor liquid into the housing and solidifying the precursor liquid at the strain gauge to form an ampulla cap includes: Inject the precursor liquid into the shell, and let ultraviolet light irradiate the precursor liquid in the semicircular tube that is radially opposite to the through hole through the through hole, and maintain it for a first preset time to obtain a semi-finished membrane. The precursor solution is discharged, and ultraviolet light is irradiated onto the semi-finished membrane through the through-hole and maintained for a second preset time to obtain the ampulla cap.

9. The method for fabricating a fluid angular acceleration sensor according to claim 7, characterized in that, The precursor solution includes a photoinitiator, a crosslinking agent, choline chloride, and acrylic acid; The preparation method of the precursor solution is as follows: Obtain 8.5 mL–9.5 mL of acrylic acid and 10.0 g–11.5 g of choline chloride, heat to the first preset temperature and stir continuously to obtain a deep eutectic solvent; Cool the eutectic solvent to a second preset temperature, add 0.008 g–0.015 g of crosslinking agent, 0.015 g–0.025 g of photoinitiator, and 65 mL–75 mL of deionized water and stir continuously to obtain the precursor solution.

10. A mold for manufacturing, characterized in that, The method for fabricating the fluid angular acceleration sensor according to any one of claims 7-9, wherein the fabrication mold comprises: Bottom cover; The upper cover, which fits with the bottom cover, encloses an assembly cavity for fixing the housing or the semicircular tube. At least one of the upper cover and the bottom cover has a light-transmitting hole that communicates with the assembly cavity and is positioned opposite a through hole on the semicircular tube. The lamp holder has a mounting position for mounting a UV lamp, the mounting position being used to align the light-emitting side of the UV lamp with the light-transmitting hole.

Images