Passive ultrasonic resonance driving device

Abstract

The invention relates to the technical field of acoustic driving, in particular to a passive ultrasonic resonance driving device. The device comprises a resonant cavity body, a standing wave focusing assembly, a spiral torque assembly and a friction gradient assembly are sequentially arranged in an inner cavity of the resonant cavity body, and the standing wave focusing assembly is used for focusing external incident ultrasonic waves to form standing wave nodes, generating vertical acoustic radiation force and driving a floating ball in the inner cavity of the standing wave focusing assembly to move in the axial direction. The spiral torque assembly is located below the standing wave focusing assembly, and a spiral groove of the spiral torque assembly converts longitudinal vibration into rotating torque. Through 20-100kHz broadband ultrasonic adjustment, the functions of lifting of the standing wave focusing assembly, rotation of the spiral torque assembly and sliding of the friction gradient assembly are activated in sequence, the function singleness of a traditional passive acoustic device (such as acoustic tweezers capable of only suspending) is broken through, a floating ball is driven to ascend and descend at 20kHz, cell interlayer positioning is completed, and the operation is simple and convenient. The 60 kHz trigger push teeth and the straight tooth grooves are in contact meshing through acoustic radiation force, so that the rotating shaft rotates, and the micro cutting tool bit is controlled.

Description

Technical Field

[0001] The present invention relates to the field of acoustic driving technology, in particular to a passive ultrasonic resonance driving device. Background Art

[0002] Traditional ultrasonic drive devices require external circuits for power supply and signal control, making them difficult to miniaturize. For example, medical endoscope robots must integrate power and drive circuits within a millimeter-scale space. This is technically challenging and has limited reliability. Active components are prone to failure in extreme environments such as high temperature, high pressure, and within the body, and electromagnetic coils can interfere with precision instruments (such as magnetic resonance imaging equipment). This makes them unsuitable for specialized scenarios. For example, a waterproof drive with publication number CN103812266B is available. Passive ultrasound refers to a device that does not rely on built-in power supply, circuits, or magnetic components, but relies entirely on external input ultrasonic energy to achieve its function. It is suitable for implantation in the body and strong electromagnetic interference environments. At the same time, passive acoustic devices have a single function and can only achieve suspension or simple vibration. (For example, acoustic tweezers and acoustic levitators) can only achieve suspension or tiny vibration of objects through the sound field. They lack the ability to control multi-degree-of-freedom motion. The single-function structure makes it difficult to reuse acoustic wave energy, resulting in energy waste and limiting the practicality of the device. Summary of the Invention

[0003] The object of the present invention is to provide a passive ultrasonic resonance driving device to solve the problems raised in the above background technology.

[0004] To achieve the above-mentioned objectives, the present invention provides a passive ultrasonic resonance driving device, comprising a resonance cavity main body, wherein the inner cavity of the resonance cavity main body is sequentially provided with a standing wave focusing component, a spiral torque component, and a friction gradient component, wherein the standing wave focusing component is used to focus the external incident ultrasonic wave to form a standing wave node, generate a vertical sound radiation force, and drive the float in its inner cavity to move axially, the spiral torque component is located below the standing wave focusing component, and its spiral groove converts the longitudinal vibration into a rotational torque, driving the rotating shaft to drive the float to rotate, the friction gradient component is located at the bottom of the spiral torque component, and its asymmetric serrated structure generates a directional friction force through the vibration phase difference, thereby realizing the overall sliding of the device, the device has no built-in power supply, circuit and magnetic components, and relies entirely on external ultrasonic energy input, the resonance cavity main body material is silicon nitride ceramic or titanium aluminum alloy, and the cavity structure accounts for ≥40%.

[0005] The external incident ultrasonic wave is focused by the standing wave focusing component to form a standing wave field, and the vertical acoustic radiation force is generated at the standing wave node, driving the float to perform reciprocating linear motion along the axis of the resonance cavity to achieve linear motion. When ultrasonic waves of different frequencies are incident from the outside, the spiral grooves of the spiral torque component convert the longitudinal vibration into rotational torque, driving the shaft to drive the float to rotate, and continuing to switch the ultrasonic frequency so that the asymmetric sawtooth structure at the bottom of the friction gradient component vibrates after switching the ultrasonic frequency. The vibration phase difference is used to generate unequal friction forces on both sides of the sawtooth. The friction between the steep slope side of the sawtooth and the ground is greater than that between the gentle slope side, causing the device to tend to slide in the direction of the gentle slope, and finally realizing the directional sliding of the device driven by the friction gradient component. The lifting, rotation and sliding are activated through frequency adjustment through the same external ultrasonic transmitter without the need for a complex mechanical switching mechanism.

[0006] As a further improvement of the present technical solution, the standing wave focusing assembly includes a hemispherical groove fixed on the inner wall of the resonance cavity body with the opening facing upward, the inner cavity of the hemispherical groove is provided with a float, the float is made of hollow alumina ceramic, and the surface is coated with a diamond-like coating, the inner wall of the hemispherical groove is provided with a through groove, the inner wall of the through groove maintains a gap with the surface of the rotating shaft, and the surface of the through groove is fixedly connected to a conical funnel through a support rod, and a gap is maintained between the conical funnel and the through groove to form a sound wave guide channel; After the external ultrasonic transmitter transmits sound waves into the main body of the resonance cavity, the hemispherical groove of the standing wave focusing component reflects and interferes with the incident ultrasonic wave multiple times based on the geometric characteristics of the curved surface and the principle of acoustic reflection, forming a standing wave field in the groove. The float located at the standing wave node is affected by the vertically upward and continuously accumulating acoustic radiation force. When this force is greater than its own gravity, it moves upward along the axial direction of the resonance cavity. In addition, the float is made of hollow alumina ceramic and coated with diamond-like coating. It has low density and light weight. The moment of inertia is less than 1 / 10 of that of a traditional solid metal ball. It can start quickly with a response speed of microseconds, and the acceleration can reach 10³m / s². The low-friction surface reduces resistance during movement.

[0007] As a further improvement of the present technical solution, the spiral torque assembly includes a connecting plate fixed to the inner cavity of the resonance cavity body, and an Archimedean spiral groove is provided on the surface of the connecting plate. The pitch of the spiral groove is in the ratio of 1:10 to 1:30 to the external ultrasonic wavelength. A notch is provided on the top of the connecting plate, and a push tooth is fixedly connected to the inner wall of the notch. The rotating shaft rotates in the notch, and the surface of the rotating shaft maintains a distance from the inner wall of the notch. The top of the rotating shaft is fixedly connected to the surface of the float, and a straight tooth groove is provided on the surface of the rotating shaft corresponding to the push tooth position. The helix angle of the spiral groove is 15°-30°, and the push teeth are arranged along the spiral tangent direction, so that the tangential component of the traveling wave vibration is maximized and converted into driving torque, and the meshing of the push tooth and the straight tooth groove is achieved through acoustic radiation force.

[0008] When the external ultrasonic frequency is switched to match the geometric parameters of the Archimedean spiral groove, the groove excites traveling wave resonance, and the surface particles vibrate along an elliptical trajectory to form a spiral traveling wave field. The groove acts as the central node to perform eccentric elliptical vibration, driving the push tooth to periodically displace tangentially. When the push tooth approaches the straight tooth groove, the acoustic radiation force causes it to cut into the groove, and the normal force is decomposed into a tangential driving force through the wedge-shaped profile, driving the shaft to rotate. When the vibration is reversed, the push tooth moves away, the acoustic radiation force decays, and the shaft maintains unidirectional rotation due to inertia, realizing non-contact force transmission characteristics similar to ratchet and pawl through acoustic radiation force.

[0009] As a further improvement of the present technical solution, the friction gradient assembly includes a bottom plate fixedly connected to the bottom of the resonant cavity body, the bottom of the bottom plate is provided with an asymmetric sawtooth groove, the top of the bottom plate is fixedly connected to a support shaft, and the inner wall of the support shaft is in contact with the surface of the rotating shaft; When the external ultrasonic frequency switches, the energy is transmitted through the standing wave focusing component s1 → spiral torque component s2 → rotating shaft → support shaft, and finally to the base plate s3. The base plate is forced to vibrate, and the base plate vibrates accordingly. The vibration phase difference is used to generate unequal friction forces on both sides of the sawtooth. The friction force between the steep slope side of the sawtooth and the ground is greater than that between the gentle slope side, causing the device to tend to slide toward the gentle slope at d1-d2.

[0010] As a further improvement of the present technical solution, the resonant modes of different functional components in the resonant cavity body are selectively excited by adjusting the output frequency of the external ultrasonic transmitter: First frequency range (20kHz to 40kHz): activating the longitudinal standing wave resonance of the standing wave focusing assembly (200), driving the floating ball (220) to move up and down along the axial direction; Second frequency range (45kHz to 55kHz): driving the float (220) to fall back axially; A third frequency range (60 kHz to 80 kHz): activating the traveling wave resonance of the spiral groove of the spiral torque component (300) to drive the rotating shaft (340) to rotate; A fourth frequency range (85kHz to 100kHz): exciting the asymmetric sawtooth structure vibration phase difference of the friction gradient component (400) to achieve directional sliding of the entire device.

[0011] Compared with the prior art, the present invention has the following beneficial effects: 1. This passive ultrasonic resonance drive device completely eliminates active components such as batteries, motors, and electromagnetic coils by relying on external ultrasonic energy input, solving the technical challenge of integrating electronic devices in millimeter-scale space. The absence of electronic components means that it is not affected by extreme environments such as high temperature (resistant to 800°C), high pressure (100MPa), and strong corrosion (pH1-14). In the highly acidic environment of the digestive tract (pH≈1.5), the resonant cavity body made of silicon nitride ceramic can still work stably, while traditional electronic components will quickly fail due to electrolyte corrosion. In the high radiation area of nuclear power plants (dose>10 4 The device has no semiconductor components and its radiation resistance is more than 100 times that of traditional electromagnetic drive devices. The design without magnetic components enables it to operate stably in strong magnetic fields (such as 3T MRI equipment), avoiding the eddy current loss and magnetic field interference of traditional electromagnetic drives, making it suitable for MRI-guided precision surgery. 2. This passive ultrasonic resonance drive device uses 20-100kHz broadband ultrasonic modulation to sequentially activate the functions of the standing wave focusing component lifting, the spiral torque component rotating, and the friction gradient component sliding. This breaks through the functional simplicity of traditional passive acoustic devices (such as acoustic tweezers that can only levitate). 20kHz drives the float to lift and lower, completing interlayer positioning of cells. 60kHz triggers the push teeth and straight tooth grooves to achieve contact and engagement through acoustic radiation force, causing the shaft to rotate and control the micro-cutting head. 90kHz triggers the inclination difference between steep and gentle slopes, generating a net friction force difference within the vibration cycle, causing the friction gradient component to slide in a certain direction, allowing the device to move along the blood vessel wall to the next lesion. Different frequency ranges correspond to unique resonant modes, and energy is concentrated on the target component (for example, 50-80kHz only excites the spiral torque component, leaving other components almost stagnant). Since the device can achieve various motion modes such as lifting, rotating, and sliding through ultrasonic waves of different frequencies, as long as the device to be driven is reasonably connected to the corresponding moving parts of the device (such as a float), it can drive other devices, not just the micro-cutting head. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the overall structure assembly of the present invention; Figure 2 It is a schematic diagram of the overall front plan structure of the present invention; Figure 3 This is a schematic structural diagram of the spiral torque assembly of the present invention; Figure 4 This is a schematic diagram of the hemispherical groove structure of the present invention; Figure 5 It is a schematic diagram of the rotating shaft structure of the present invention; Figure 6 Schematic diagram of the bottom plate structure of the present invention; Figure 7For the present invention Figure 6 A schematic diagram of the enlarged structure at point A; Figure 8 For the present invention Figure 6 A schematic diagram of the enlarged structure at point B; The meaning of each number in the figure is: 100. Resonance cavity body; 200, standing wave focusing assembly; 210, hemispherical groove; 2101, through groove; 2102, conical funnel; 220, float; 300, spiral torque assembly; 310, connecting plate; 320, spiral groove; 330, notch; 3301, push tooth; 340, rotating shaft; 3401, straight tooth groove; 400, friction gradient assembly; 410, base plate; 4101, asymmetric serrated groove; 420, support shaft. DETAILED DESCRIPTION

[0013] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0014] Example 1: Please refer to Figure 1 Figure 8 As shown, this embodiment provides a passive ultrasonic resonance driving device, including a resonance cavity body 100, wherein the inner cavity of the resonance cavity body 100 is sequentially provided with a standing wave focusing component 200, a spiral torque component 300, and a friction gradient component 400; The standing wave focusing assembly 200 is used to focus external incident ultrasonic waves to form standing wave nodes, generate vertical acoustic radiation force, and drive the float 220 in its inner cavity to move axially; The spiral torque assembly 300 is located below the standing wave focusing assembly 200. Its spiral groove 310 converts longitudinal vibration into rotational torque, driving the shaft 340 to rotate the float 220. The friction gradient component 400 is located at the bottom of the spiral torque component 300. The bottom of the component is provided with an asymmetric sawtooth structure to generate directional friction force through the vibration phase difference, thereby achieving the overall sliding of the device. The device has no built-in power supply, circuit or magnetic components and relies entirely on external ultrasonic energy input; Considering that traditional ultrasonic drive devices require external circuit power supply and signal control, miniaturization is difficult to achieve. For example, medical endoscope robots need to integrate power supply and drive circuits in millimeter-level space, which is technically difficult and has limited reliability. Active components are prone to failure in extreme environments such as high temperature, high pressure, and in vivo, and electromagnetic coils may interfere with precision instruments (such as nuclear magnetic resonance equipment), which cannot meet the needs of special scenarios. Therefore, external ultrasonic energy input is used to avoid the technical difficulties of integrating power supply in millimeter-level space (such as the miniaturization bottleneck of medical endoscope robots). It is suitable for extreme environments without electronic components and can work stably in environments such as high temperature, high pressure, and in vivo (such as the digestive tract), avoiding the risk of failure of active components. At the same time, magnetic components such as electromagnetic coils avoid interference with precision instruments (such as nuclear magnetic resonance equipment), making it suitable for scenarios such as medical image guidance.

[0015] At the same time, considering that the passive acoustic device has a single function and can only achieve suspension or simple vibration, (such as acoustic tweezers, acoustic levitators) can only achieve object suspension or small vibration through the sound field, lacking multi-degree-of-freedom motion control capabilities, and a single functional structure is difficult to reuse sound wave energy, resulting in energy waste, limiting the practicality of the device. Therefore, the external incident ultrasonic wave is focused by the standing wave focusing component 200 to form a standing wave field, and a vertical acoustic radiation force is generated at the standing wave node, driving the float 220 to make reciprocating linear motion along the axis of the resonance cavity to achieve linear motion. When ultrasonic waves of different frequencies are incident from the outside, the spiral The spiral groove 310 of the torque assembly 300 converts longitudinal vibration into rotational torque, driving the rotating shaft 340 to rotate the float 220. If the equipment needs to slide, the ultrasonic frequency is switched to vibrate the asymmetric sawtooth structure at the bottom of the friction gradient assembly 400, and the vibration phase difference is used to generate unequal friction forces on both sides of the sawtooth. The friction between the steep slope side of the sawtooth and the ground is greater than that between the gentle slope side, causing the device to tend to slide in the direction of the gentle slope, and finally achieving directional sliding of the device driven by the friction gradient assembly 400. The lifting, rotation, and sliding are activated through frequency adjustment through the same external ultrasonic transmitter, without the need for a complex mechanical switching mechanism.

[0016] On the basis of the above, the specific structure is disclosed in detail: The resonant cavity body 100 is made of silicon nitride ceramic or titanium aluminum alloy, and the cavity structure accounts for ≥40%; Silicon nitride ceramics (Si3N4) have excellent acoustic conductivity properties, with a sound velocity of up to 10,000 m / s (far exceeding aluminum's 6,300 m / s). This can reduce the propagation delay of ultrasound waves within the cavity wall (for example, the propagation time for a 10 mm thickness is only 1 μs), ensuring the synchronous response of different functional components. They also have high strength and chemical stability, with a bending strength of 800-1,000 MPa (2-3 times that of titanium aluminum alloy). They can withstand the alternating stress caused by high-frequency vibration (amplitude ±50 μm at 100 kHz) and avoid fatigue cracking. They are extremely corrosion-resistant (resistant to pH 1-14 solutions) and are suitable for harsh environments such as humidity, acidity, and alkali (such as body fluid environments in biomedical scenarios). The cavity volume directly affects the cavity's natural resonant frequency. By increasing the cavity ratio (for example, from 30% to 50%), the cavity fundamental frequency can be reduced from 80 kHz to 50 kHz, covering a wider frequency adjustment range (20-100 kHz).

[0017] In order to enable the standing wave focusing assembly 200 to drive the floating ball 220 to move upward, it is necessary to further disclose the parts of the standing wave focusing assembly 200. Therefore, the standing wave focusing assembly 200 includes a hemispherical groove 210 fixed to the inner wall of the resonance cavity body 100 with an upward opening, and a floating ball 220 is provided in the inner cavity of the hemispherical groove 210; An external ultrasonic transmitter emits ultrasonic waves toward the resonance cavity body 100. When the sound waves enter the standing wave focusing assembly 200, they are fixed on the inner wall of the resonance cavity body 100. The hemispherical groove 210 uses its curved surface geometric characteristics to reflect and focus the incident ultrasonic waves. According to the principle of acoustic reflection, the ultrasonic waves are reflected multiple times on the curved surface of the hemispherical groove 210. These reflected waves superimpose and interfere with each other to form a standing wave field at a specific position inside the groove. The float 220 is located at the standing wave node, where the acoustic radiation force is most concentrated and directed vertically upward. As the external ultrasonic energy continues to be input, the acoustic radiation force continues to accumulate. When this force is greater than the gravity of the float 220 itself, it can overcome the effect of gravity and drive the float 220 to move upward along the axis of the resonance cavity.

[0018] In order to reduce the inertial resistance of the float 220 during startup, enable it to respond more sensitively to the acoustic radiation force generated by ultrasound, and improve the dynamic performance of motion control, the float 220 is made of hollow alumina ceramic with a diamond-like coating on the surface; Alumina ceramics have a density of only 3.5g / cm³, and the internal hollow structure further reduces mass, reducing the moment of inertia to less than 1 / 10 of that of a traditional solid metal ball. When external ultrasonic waves (20-50kHz) are focused through the hemispherical groove 210 to form a standing wave field, the hollow float 220 is subjected to vertical acoustic radiation forces at the standing wave nodes. Due to its light mass, a small acoustic radiation force can drive the float to start quickly, with an acceleration of up to 10³m / s², achieving a microsecond response. When the float moves axially within the hemispherical groove 210, the low-friction surface reduces contact resistance with the inner wall of the groove, allowing the acoustic radiation force to be more efficiently converted into kinetic energy.

[0019] In order to enable the spiral torque assembly 300 to rotate the shaft 340 when the external ultrasonic wave switches frequency, the spiral torque assembly 300 includes a connecting plate 310 fixed to the inner cavity of the resonant cavity body 100. The connecting plate 310 has an Archimedean spiral groove 320 on its surface. The ratio of the pitch of the spiral groove 320 to the wavelength of the external ultrasonic wave is 1:10 to 1:30. A notch 330 is formed at the top of the connecting plate 310, and a push tooth 3301 is fixedly connected to the inner wall of the notch 330. The rotating shaft 340 rotates in the notch 330, and a distance is maintained between the surface of the rotating shaft 340 and the inner wall of the notch 330. The top of the rotating shaft 340 is fixedly connected to the surface of the float 220, and a straight tooth groove 3401 is formed on the surface of the rotating shaft 340 at the position corresponding to the push tooth 3301. The surface material of the straight tooth groove 3401 is a high-coefficient friction layer. The meshing of the push teeth 3301 and the straight tooth grooves 3401 is achieved by acoustic radiation force; The helix angle of the spiral groove 320 is 15°-30°, and the push teeth 3301 are arranged along the tangential direction of the spiral, so that the tangential component of the traveling wave vibration is converted into driving torque to the maximum extent; When the external ultrasonic frequency is switched, the Archimedean spiral groove 320 generates traveling wave resonance due to its geometric parameters matching the wavelength of the sound wave. The particles on the groove surface vibrate along an elliptical trajectory, forming a traveling wave field propagating along the spiral direction. The slot 330 serves as the central node of the spiral, and its vibration trajectory exhibits eccentric elliptical motion, driving the push tooth 3301 to make periodic tangential displacement. When the push tooth 3301 approaches the straight tooth groove 3401 with the vibration, the acoustic radiation force causes the push tooth to cut into the groove, forming a meshing state similar to that of a ratchet and pawl. The wedge-shaped profile of the push tooth 3301 decomposes the normal force into a tangential driving force, driving the rotating shaft 340 to rotate. When the vibration is reversed, the push tooth 3301 moves away from the straight tooth groove 3401, the spacing increases, the acoustic radiation force decays, and the rotating shaft 340 continues to rotate due to inertia, achieving a unidirectional motion characteristic similar to that of a ratchet mechanism.

[0020] In order to allow external ultrasonic waves to smoothly pass through the standing wave focusing assembly 200 and reach the surface of the spiral groove 320, a through groove 2101 is formed on the inner wall of the hemispherical groove 210. A gap is maintained between the inner wall of the through groove 2101 and the surface of the rotating shaft 340. A conical funnel 2102 is fixedly connected to the surface of the through groove 2101 via a support rod. A gap is maintained between the conical funnel 2102 and the through groove 2101 to form a sound wave guide channel. The bottom of the conical funnel 2102 is located above the connecting plate 310. The external ultrasonic wave is focused in the hemispherical groove 210 for s1, and the energy diffuses downward to the through groove 2101. The through groove 2101 sends the sound wave down to the parabola of the conical funnel 2102. Since the smaller opening diameter of the upper part of the conical funnel 2102 preliminarily constrains the divergent sound wave, forming an approximately parallel beam, the gradually expanding diameter of the lower part of the funnel causes the sound wave to be totally reflected on the inner wall of the parabola. Following the principle of geometric acoustics, the sound wave energy is concentrated to the bottom opening, and finally projected to the spiral groove 320s2 on the surface of the connecting plate 310 in the form of a high-intensity sound beam. When the external ultrasonic frequency is adjusted to drive the float 2 20 moves upward, a standing wave field is formed in the hemispherical groove 210 of the standing wave focusing assembly 200, and a vertical upward acoustic radiation force is generated at the standing wave node, driving the float 220 to rise synchronously along the axial direction, and the rotating shaft 340 fixedly connected at its bottom moves upward accordingly. At this time, the straight tooth groove 3401 on the surface of the rotating shaft 340 gradually approaches and contacts the inner wall of the conical funnel 2102. When the ultrasonic equipment stops working, the standing wave field disappears, and the upward driving force of the float 220 decreases sharply. At this time, the friction resistance between the surface of the straight tooth groove 3401 and the inner wall of the conical funnel 2102 can maintain the position of the float 220.

[0021] In order to enable the friction gradient assembly 400 to slide in a directional manner when receiving ultrasonic vibrations, it is necessary to further disclose the components of the friction gradient assembly 400. Therefore, the friction gradient assembly 400 includes a bottom plate 410 fixedly connected to the bottom of the resonant cavity body 100. The bottom of the bottom plate 410 is defined by an asymmetric sawtooth groove 4101. The top of the bottom plate 410 is fixedly connected to a support shaft 420. The inner wall of the support shaft 420 contacts the surface of the rotating shaft 340. When the external ultrasonic frequency is switched, the energy is transmitted through the standing wave focusing component 200s1 → spiral torque component 300s2 → rotating shaft 340 → support shaft 420, and finally to the bottom plate 410s3. The bottom plate 410 is forced to vibrate, and the bottom plate 410 vibrates accordingly. The vibration phase difference is used to generate unequal friction forces on both sides of the sawtooth. The friction force between the steep slope side of the sawtooth and the ground is greater than that between the gentle slope side, causing the device to tend to slide toward the gentle slope at d1-d2.

[0022] In order to enable external ultrasound to activate different motion modes by switching different frequencies, the required ultrasound frequencies need to be disclosed. Therefore, by adjusting the output frequency of the external ultrasound transmitter, the resonance modes of different functional components in the resonance cavity body 100 can be selectively excited: First frequency range (20kHz to 40kHz): Activates the longitudinal standing wave resonance of the standing wave focusing assembly 200 and drives the float 220 to move up and down in the axial direction; The second frequency range (45kHz to 55kHz): drives the float 220 to fall back axially; The third frequency range (60kHz to 80kHz): activates the traveling wave resonance of the spiral groove of the spiral torque component 300 to drive the rotating shaft 340 to rotate; The fourth frequency range (85kHz to 100kHz): excites the vibration phase difference of the asymmetric sawtooth structure of the friction gradient component 400 to achieve directional sliding of the entire device; 20kHz is the typical starting frequency of ultrasound, which is beyond the audible range of the human ear. 100kHz is considered high-frequency ultrasound and is suitable for micron-level precision driving (such as cell manipulation and micro-robotics). Common ultrasonic driving frequencies in medical and industrial applications (such as 40kHz cleaning and 60kHz welding) are all within this range. Ascending stage (20kHz–40kHz): The hemispherical groove 210 of the standing wave focusing assembly 200 reflects and focuses the ultrasonic wave, forming a standing wave node at the center of the groove. The vertically upward acoustic radiation force drives the hollow alumina ceramic float 220 to rise axially. Falling stage (45kHz–55kHz): The frequency is adjusted beyond the resonance range of the standing wave assembly 200, and the float 220 falls back at a uniform speed under the action of the acoustic radiation force; Static locking: When the ultrasonic wave stops working, the straight tooth groove 3401 of the rotating shaft 340 at the bottom of the float 220 contacts the inner wall of the conical funnel 2102, and the high static friction coefficient and the axial constraint of the funnel keep the float 220 stationary. By directly corresponding to unique motion modes (longitudinal lifting, rotation, and directional sliding) in different frequency ranges, interference between multiple modes is avoided and the accuracy of the execution of actions is ensured. 20~40kHz only stimulates the axial movement of the float 220 and has no overlap with the rotation mode. 80~100kHz specifically drives the friction gradient component to avoid accidental contact with the spiral torque structure. By quickly adjusting the frequency (such as controlling the ultrasonic transmitter with an electrical signal), it can switch between different motion modes in milliseconds to adapt to the dynamic needs of complex scenarios (such as lifting and positioning first, then rotation operation, and finally directional movement).

[0023] After the device is implanted in the body, medical imaging examinations reveal that its current position does not meet the treatment needs. The position of the device can be adjusted by adjusting the ultrasonic frequency. The output frequency of the external ultrasonic transmitter is adjusted to 80-100kHz, and the friction gradient component 400 at the bottom of the device is activated. This component uses the vibration phase difference of the asymmetric sawtooth structure to generate directional friction on the surface of the tissue in the body, causing the device to slowly slide along a preset path. At the same time, by switching to a 20-40kHz frequency to fine-tune the standing wave focusing component 200, the acoustic radiation force is used to drive the float 220 to assist in calibrating the height, avoiding the risk of trauma caused by a secondary operation and significantly reducing the patient's pain and infection probability.

[0024] In summary, the workflow of the present invention is: External ultrasonic waves at 20-40kHz are incident on the hemispherical groove 210 of the standing wave focusing component 200, and are reflected by the curved surface to form a standing wave field, forming a standing wave node at the center of the groove. The standing wave node generates a vertical upward acoustic radiation force, which drives the hollow alumina ceramic float 220 to overcome gravity and move axially. If the float 220 rises too high, it needs to be adjusted. The frequency of 45-55kHz is adjusted to exceed the resonance range of the standing wave component 200. Under the action of the acoustic radiation force, the float 220 falls back at a uniform speed, and the frequency is switched to 60-80kHz. The ultrasonic wave is focused s1 in the hemispherical groove 210, and the energy diffuses downward to the through groove 2101. The through groove 2101 guides the sound wave down to the parabola of the conical funnel 2102. Since the smaller opening diameter of the upper part of the conical funnel 2102 initially constrains the divergent sound wave, forming an approximately parallel beam. The gradually expanding diameter of the lower part of the funnel causes the sound wave to be totally reflected on the inner wall of the parabola. Following the principle of geometric acoustics, the sound wave energy is concentrated to the bottom opening and finally projected onto the spiral groove on the surface of the connecting plate 310 in the form of a high-intensity sound beam. At 320s2, the Archimedean spiral groove 320 excites traveling wave resonance, and the particles on the groove surface make elliptical vibrations. The push teeth 3301 on the inner wall of the notch 330 approach the straight tooth groove 3401 with the vibration. The acoustic radiation force causes the push teeth 3301 to cut into the straight tooth groove 3401. The wedge-shaped profile decomposes the normal force into a tangential driving force, driving the shaft 340 to rotate. At this time, the shaft 340 drives the float 220 to rotate. At the same time, the straight tooth groove 3401 of the shaft 340 at the bottom of the float 220 contacts the inner wall of the conical funnel 2102, utilizing the high static friction coefficient and The axial constraint of the funnel keeps the float 220 stationary. Only when the shaft 340 rotates can the float 220 rotate, and the frequency is increased to 80-100kHz. The energy is transmitted to the bottom plate 410 of the friction gradient assembly 400 through the shaft 340, causing the asymmetric sawtooth groove 4101 at the bottom of the bottom plate 410 to generate a friction difference within the vibration cycle. The vibration phase difference is used to generate unequal friction forces on both sides of the sawtooth. The friction between the steep slope side of the sawtooth and the ground is greater than that between the gentle slope side, causing the device to tend to slide toward the gentle slope at d1-d2.

[0025] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A passive ultrasonic resonance driving device, comprising a resonance cavity body (100), characterized in that: The inner cavity of the resonant cavity body (100) is provided with a standing wave focusing component (200), a spiral torque component (300), and a friction gradient component (400) in sequence; The standing wave focusing assembly (200) is used to focus external incident ultrasonic waves to form standing wave nodes, generate vertical acoustic radiation force, and drive the floating ball (220) in its inner cavity to move axially; The spiral torque component (300) is located below the standing wave focusing component (200), and its spiral groove (310) converts longitudinal vibration into rotational torque, driving the rotating shaft (340) to drive the floating ball (220) to rotate; The friction gradient component (400) is located at the bottom of the spiral torque component (300), and an asymmetric sawtooth structure is provided at the bottom thereof to generate directional friction force through vibration phase difference, thereby achieving overall sliding of the device; The device has no built-in power supply, circuit or magnetic component and completely relies on external ultrasonic energy input.

2. The passive ultrasonic resonance driving device according to claim 1, characterized in that: The material of the resonant cavity body (100) is silicon nitride ceramic or titanium aluminum alloy, and the cavity structure accounts for ≥40%.

3. The passive ultrasonic resonance driving device according to claim 1, characterized in that: The standing wave focusing assembly (200) comprises a hemispherical groove (210) fixed on the inner wall of the resonance cavity body (100) with its opening facing upwards, and a floating ball (220) is provided in the inner cavity of the hemispherical groove (210).

4. The passive ultrasonic resonance driving device according to claim 1, wherein: The float (220) is made of hollow alumina ceramics, and its surface is coated with a diamond-like coating.

5. The passive ultrasonic resonance driving device according to claim 1, characterized in that: The spiral torque assembly (300) includes a connecting plate (310) fixed to the inner cavity of the resonance cavity body (100), an Archimedean spiral groove (320) is provided on the surface of the connecting plate (310), and the ratio of the pitch of the spiral groove (320) to the wavelength of the external ultrasonic wave is 1:10 to 1:30; A notch (330) is provided at the top of the connecting plate (310), and a push tooth (3301) is fixedly connected to the inner wall of the notch (330). The rotating shaft (340) rotates in the notch (330), and a distance is maintained between the surface of the rotating shaft (340) and the inner wall of the notch (330). The top of the rotating shaft (340) is fixedly connected to the surface of the float (220), and a straight tooth groove (3401) is provided on the surface of the rotating shaft (340) at a position corresponding to the push tooth (3301). The surface material of the straight tooth groove 3401 is a high-coefficient friction layer.

6. The passive ultrasonic resonance driving device according to claim 5, characterized in that: The meshing of the push teeth (3301) and the straight tooth grooves (3401) is achieved through acoustic radiation force.

7. The passive ultrasonic resonance driving device according to claim 5, characterized in that: The helical groove (320) has a helical pitch angle of 15°-30°, and the push teeth (3301) are arranged along the helical tangent direction, so that the tangential component of the traveling wave vibration is converted into driving torque to the maximum extent.

8. The passive ultrasonic resonance driving device according to claim 1, characterized in that: A through groove (2101) is provided on the inner wall of the hemispherical groove (210), a gap is maintained between the inner wall of the through groove (2101) and the surface of the rotating shaft (340), and a conical funnel (2102) is fixedly connected to the surface of the through groove (2101) via a support rod, a gap is maintained between the conical funnel (2102) and the through groove (2101), forming a sound wave guide channel, and the bottom of the conical funnel (2102) is located above the connecting plate (310).

9. The passive ultrasonic resonance driving device according to claim 1, characterized in that: The friction gradient component (400) comprises a bottom plate (410) fixedly connected to the bottom of the resonance cavity body (100), an asymmetric sawtooth groove (4101) being provided at the bottom of the bottom plate (410), and a support shaft (420) being fixedly connected to the top of the bottom plate (410), wherein the inner wall of the support shaft (420) contacts the surface of the rotating shaft (340).

10. The passive ultrasonic resonance driving device according to claim 1, characterized in that: By adjusting the output frequency of the external ultrasonic transmitter, the resonance modes of different functional components in the resonance cavity body (100) are selectively excited: First frequency range (20kHz to 40kHz): activating the longitudinal standing wave resonance of the standing wave focusing assembly (200), driving the floating ball (220) to move up and down along the axial direction; Second frequency range (45kHz to 55kHz): driving the float (220) to fall back axially; A third frequency range (60 kHz to 80 kHz): activating the traveling wave resonance of the spiral groove of the spiral torque component (300) to drive the rotating shaft (340) to rotate; A fourth frequency range (85kHz to 100kHz): exciting the asymmetric sawtooth structure vibration phase difference of the friction gradient component (400) to achieve directional sliding of the entire device.

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