Method for generating micro-scale cylindrical high-speed acoustic beam in liquid environment and its application

Abstract

The present application provides a method for generating a micro-scale columnar high-speed acoustic beam in a liquid environment, comprising: a liquid environment; a high-frequency resonator, which generates 0.5-30 GHz ultrasonic waves to act on the liquid environment during operation, generating a directional fluid motion along the direction of propagation of the sound wave in the liquid at the solid-liquid interface, i.e., a columnar focused acoustic beam; the high-frequency resonator is driven to operate in at least one driving cycle with a first power, each driving cycle including a first stage and a second stage, the first stage driving the high-frequency resonator to operate, and the second stage stopping the driving; the magnitude of the first power causes the high-frequency resonator to generate an acoustic beam in the first stage; and the duration of the first stage at the first power is less than the second threshold or the duty cycle of the first stage in one driving cycle is less than the first threshold. Corresponding applications are also provided, such as a method for directional transport of liquids or particles in liquids, and a method for processing target objects.

Description

Technical Field

[0001] The present application relates to the field of microfluidics technology, and in particular to a method for generating a microscale columnar high-speed acoustic beam in a liquid environment and its application. Background Art

[0002] In the field of acoustofluid technology, acoustofluid is a stable flow caused by sound waves. This phenomenon manifests itself as momentum transfer from sound waves to fluid motion. When ultrasonic waves propagate in a sound-absorbing fluid, they cause the medium to move as a whole. Among them, since the special sound waves generated by the high-frequency resonator are absorbed faster in the fluid and have a shorter propagation distance, their acoustofluid effect is more obvious. The regional vibration generated by the working interface of the high-frequency resonator forms a traveling wave in the liquid, and exerts a continuous thrust on the local liquid in the liquid environment, thereby driving the local liquid to move in the direction of the traveling wave propagation. At the same time, based on the viscosity of the fluid, the surrounding liquid of the local liquid will be driven to move together, thereby forming a flow effect of the liquid in the direction opposite to the working interface. Among them, the local liquid refers to the part of the liquid facing the working interface of the high-frequency resonator. As the high-frequency resonator continues to work, the liquid continues to flow, which will further generate secondary fluids such as liquid vortices and convection in the liquid environment.

[0003] In addition to driving liquid flow, generating eddies, and generating convection, the ultrasonic waves of high-frequency resonators can, in certain scenarios, also be used to generate a focused acoustic beam within the liquid, specifically a high-speed, cylindrical jet of fluid, aligned with the direction of the acoustic wave propagation. This beam is characterized by its alignment with the direction of the acoustic wave propagation within the liquid, its thin, cylindrical shape, and minimal mixing with the surrounding liquid, resulting in a distinct flow pattern between the beam and the surrounding liquid. This relatively stable flow allows for better momentum transfer. This characteristic of the acoustic beam can be used to manipulate the directional movement of a portion of liquid or the directional movement of materials contained within it.

[0004] Therefore, how to provide a solution to enable ultra-ultrasonic devices to generate acoustic beams in liquids is a technical problem that needs to be solved. Summary of the Invention

[0005] In view of the above problems in the prior art, the present application provides a method for generating a micro-scale cylindrical high-speed acoustic beam in a liquid environment and its application.

[0006] In a first aspect, the present application provides a method for generating a microscale columnar high-speed acoustic beam flow in a liquid environment, comprising: a liquid environment; a high-frequency resonator, which, when in operation, generates 0.5-30 GHz ultrasonic waves acting on the liquid environment to generate directional fluid motion at a solid-liquid interface along the direction of propagation of the acoustic wave in the liquid, wherein the directional fluid motion is a focused columnar acoustic beam flow; driving the high-frequency resonator with a first power to operate in at least one driving cycle, each driving cycle including a first stage and a second stage, driving the high-frequency resonator to operate in the first stage to generate 0.5-30 GHz ultrasonic waves, and stopping driving the high-frequency resonator in the second stage; wherein the magnitude of the first power enables the high-frequency resonator to generate the acoustic beam flow within the first stage.

[0007] As described above, the present application drives the high-frequency resonator with the first power of the above magnitude through each driving cycle including the first stage and the second stage, thereby generating a focused columnar acoustic beam in a liquid environment.

[0008] As a possible implementation of the first aspect, the duration of the first stage at the first power is less than a second threshold or the duty cycle of the first stage in one driving cycle is less than the first threshold, so that the temperature of the high-frequency resonator is within a third threshold.

[0009] As described above, by limiting the duration or duty cycle of the first stage, the temperature of the high-frequency resonator device or the liquid environment in which the device is located can be controlled to be within the third threshold when generating the above-mentioned acoustic beam flow, thereby avoiding overheating.

[0010] As a possible implementation of the first aspect, when the duty cycle of the high-frequency resonator during the duration of the first stage is less than a first threshold, or when the duration is less than a second threshold, the high-frequency resonator is suppressed from generating a secondary flow in the liquid environment.

[0011] As described above, by limiting the duration or duty cycle of the first stage, the generation of eddies or convection in the liquid environment can be suppressed when the above-mentioned acoustic beam is generated, so as to facilitate the control of the liquid or particles in the liquid through the acoustic beam.

[0012] As a possible implementation manner of the first aspect, the acoustic beam flow generated by the high-frequency resonator being driven reaches a maximum speed in a first stage of each driving cycle.

[0013] As a possible implementation of the first aspect, the acoustic beam generated by the high-frequency resonator is driven to reach its maximum velocity at a location between 200 and 300 microns from the high-frequency resonator. Specifically, the location of the maximum velocity is related to the input power and device size of the high-frequency resonator. In some cases, the maximum velocity location is also between 100 and 200 microns, or even less than 100 microns.

[0014] As a possible implementation method of the first aspect, the intensity of the first power is increased to increase the intensity of the sound beam flow, or the duration of the first stage or the duty cycle within a driving cycle is reduced, and the intensity of the first power is increased to increase the intensity of the sound beam flow.

[0015] As a possible implementation of the first aspect, the area of ​​the acoustic beam generation region is about 10-1,000,000 μm 2 , preferably about 100-40000 μm 2 , more preferably 1000–10000 μm 2 ; The first power is about 0.1-500W, preferably 2-50W, and more preferably 5-15W.

[0016] The second aspect of the present application provides a method for directional transport, comprising: generating an acoustic beam flow in a liquid based on any method described in the first aspect, wherein the direction of the acoustic beam flow is the direction of the directional transport; and using the acoustic beam flow to carry out the direction transport of the liquid acted upon by the high-frequency resonator, or the particles in the acted liquid, by the dragging force of the acoustic beam flow.

[0017] As a possible implementation of the second aspect, the liquid environment includes one or two layers of liquid, wherein the two layers of liquid include a first layer of liquid in contact with the interface of the high-frequency resonator, and a second layer of liquid away from the interface of the high-frequency resonator and in contact with the first layer of liquid; the directional transport includes: moving particles in a directionally in the first layer of liquid through an acoustic beam flow or directionally transporting particles in the first layer of liquid to the second layer of liquid.

[0018] As a possible implementation of the second aspect, it also includes a target substance, and the interface between the target substance and the high-frequency resonator includes the liquid environment; the directional transport includes: directing the first layer of liquid or particles in the first layer of liquid to the target substance through the acoustic beam flow.

[0019] A third aspect of the present application provides a method for processing a target object, comprising: making the distance between the interface of the high-frequency resonator and the action position of the target object 0.05-10 mm, preferably 0.1-5 mm, and most preferably between about 200-400 microns; using any method described in the first aspect to generate an acoustic beam flow, and using the acoustic beam flow to cause liquid or liquid containing particles in a liquid environment to act on the target object, so as to inject liquid into or cut the target object, or to flush, polish, or peel off surface attachments of the target object.

[0020] As a possible implementation of the first, second and third aspects, the acoustic beam flow is controlled using one or more of the following parameters: the duration of the driving cycle; the duration of the first stage and the duration of the second stage in the driving cycle; and the magnitude of the first power.

[0021] The above-mentioned solution can rapidly generate a high-speed, focused, columnar acoustic beam in a liquid environment, while maintaining device temperature within a threshold, and can reduce or avoid the generation of secondary flows. Furthermore, the above-mentioned application of the acoustic beam includes high-speed, directional transport of liquids or particles in liquids, injection or cutting of liquids or particles into target objects, and surface treatments such as scouring, polishing, and stripping of surface attachments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 a in the figure is a schematic diagram of the jet phenomenon and secondary flow phenomenon in a liquid environment. Figure 1 b is a photograph of the acoustic beam flow generated in a liquid environment using the method of the present application;

[0023] Figure 2 It is a continuous frame diagram of the process of generating the acoustic beam flow in this application;

[0024] Figure 3 It is a composite trajectory diagram of continuous time when the application generates the acoustic beam flow;

[0025] Figure 4 It is a circuit schematic diagram for implementing the method of the present application;

[0026] Figure 5 is used Figure 4 A timing diagram of an embodiment of a circuit for generating a driving unit output signal:

[0027] Figure 6 is used Figure 4 A timing diagram of another embodiment of a circuit for generating an output signal of a driving unit;

[0028] Figure 7This is a schematic diagram of the signal generator after the signal is tuned to a triangle wave;

[0029] Figure 8 is a size comparison diagram of the bulk acoustic wave device used in this application;

[0030] Figure 9 This is a schematic diagram of an application based on the method of the present application provided in an embodiment of the present application;

[0031] Figure 10 This is a schematic diagram of another application based on the method of the present application provided in an embodiment of the present application;

[0032] Figure 11 This is an analysis chart of the result data of the experiment in this application;

[0033] Figure 12 This is a schematic diagram of the dimensions of each high-frequency resonator used in the experiment of this application.

[0034] It should be understood that the sizes and shapes of the blocks in the above structural diagrams are for reference only and should not constitute an exclusive interpretation of the embodiments of the present invention. The relative positions and inclusion relationships between the blocks presented in the structural diagrams are merely schematic representations of the structural relationships between the blocks and do not limit the physical connection methods of the embodiments of the present invention. DETAILED DESCRIPTION

[0035] The technical solution provided by this application is further described below with reference to the accompanying drawings and examples. It should be understood that the system structure and business scenarios provided in the examples of this application are mainly for illustrating possible implementation methods of the technical solution of this application and should not be interpreted as the sole limitation of the technical solution of this application. It is known to those skilled in the art that with the evolution of the system structure and the emergence of new business scenarios, the technical solution provided by this application is also applicable to similar technical problems.

[0036] It should be understood that the embodiments of this application provide solutions for generating micro-scale cylindrical high-speed acoustic beams, including methods for generating micro-scale cylindrical high-speed acoustic beams and their applications. Because these technical solutions solve the same or similar problems, some repetitions may not be repeated in the following descriptions of the specific embodiments. However, these specific embodiments should be considered as cross-references and can be combined with each other.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. In the event of any inconsistency, the meanings described in this specification or the meanings derived from the contents recorded in this specification shall prevail. In addition, the terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application. In order to accurately describe the technical content in this application and to accurately understand the present invention, the following explanations or definitions are given for the terms used in this specification before describing the specific embodiments:

[0038] 1) High-frequency resonator: This device can be based on the piezoelectric effect and generates mechanical vibrations by applying voltage. In this application, a piezoelectric resonator that generates ultra-ultrasound of not less than 0.5 gigahertz (GHz) during operation is used. Preferably, a piezoelectric resonator that generates ultra-ultrasound of not less than 1 GHz and not more than 30 GHz during operation, for example, can be 2 GHz-2.5 GHz. Such piezoelectric resonators can be, for example, surface acoustic wave (SAW) devices or bulk acoustic wave (BAW) devices. For example, when using BAW, they can be film bulk acoustic wave resonators (FBARs), solid-state mounted resonators (SMRs), or Lamb wave resonators (LWRs). For convenience of description, the piezoelectric resonator that can generate ultra-ultrasound of not less than 0.5 GHz will be referred to as an ultra-ultrasound device.

[0039] 2) The jet phenomenon occurs when sound waves from ultra-ultrasonic devices interact with the solid-liquid interface. The regional vibrations generated by the working interface of a high-frequency resonator can form traveling waves in the liquid, exerting a continuous thrust on the localized liquid within the liquid environment, causing at least a portion of that liquid to move linearly along the direction of sound wave propagation. This linear motion is known as the jet phenomenon.

[0040] Secondary flow phenomenon: including eddy currents and heat reflux, is another phenomenon produced when ultra-ultrasonic devices act on liquids. It includes eddy currents (or micro-vortices) caused by the local circulation of liquids driven by the jet, and heat reflux caused by the heat generated by ultra-ultrasonic devices.

[0041] The jet phenomenon and secondary flow phenomenon can be found in Figure 1 The image and schematic diagram shown in a. Figure 1 Schematic diagram of particle capture using vortex flow shown in a.

[0042] 3) Acoustic beam flow: Acoustic beam flow is a unique type of jet phenomenon. Its characteristics are that the fluid moves at high speed along the direction of sound wave transmission and the jet is in the shape of a thin cylinder within its travel. Before the acoustic beam flow is obviously attenuated, it is basically in a laminar state with the surrounding liquid and has a low degree of mixing with the surrounding liquid. Figure 1 Figure b shows an image of the acoustic beam flow generated by the solution of the present application, taken by a high-speed camera. Figure 1 As can be seen from b in the figure, the acoustic beam is highly focused and no longer looks like Figure 1 The jets in a cluster form in Figure 1 It is clearly not visible in b Figure 1 Secondary flow phenomenon in a.

[0043] 4) Confined jet and free jet: This refers to whether the jet is restricted by the external hardware wall after it is ejected. It is divided into confined jet and free jet. Unless otherwise specified, the jet described in the embodiments of this application generally refers to a free jet.

[0044] 5) Reynolds number (Re): In fluid mechanics, the Reynolds number is a measure of the ratio of a fluid's inertial force to its viscous force. It can be used to determine whether a fluid's flow is laminar or turbulent, and it can also be used to determine the resistance encountered by an object flowing through the fluid. When the Reynolds number is small, the fluid flow is stable and laminar; conversely, when the Reynolds number is large, the fluid flow is less stable, and small changes in flow velocity tend to develop and intensify, forming a chaotic, irregular turbulent flow field. In some cases, Re = ρvd / η, where v, ρ, and η are the fluid's velocity, density, and viscosity, respectively, and d is a characteristic length, such as the diameter at the start of a jet, such as the diameter of a jet nozzle. In this application, d is used to represent the jet diameter.

[0045] 6) Signal duration within a driving cycle: In this application, the electric energy is loaded in an intermittent manner, which can be referred to Figure 5 As shown, during the power on phase (corresponding to Figure 5 The switching signal is high level), which is the signal duration in the driving cycle, also known as the first stage in the driving cycle, corresponding to the output signal of the driving unit. During the signal duration, several signals will be output. For example, when the signal generator outputs a 1GHz signal, assuming that the duration of the first stage is 1 microsecond, the driving unit will output 1000 signals during the first stage, and the power loaded during the first stage will be loaded on the 1000 signals for output. The second stage is when there is no driving signal output in the driving cycle, which also corresponds to the switching power off stage (corresponding to Figure 5 Switch signal low level).

[0046] In a specific case, for example, the first stage is completed after only one execution, which is equivalent to, or regarded as, executing only one driving cycle in the present application, and therefore this case also falls within the protection scope of the present application.

[0047] 7) In some embodiments, the driving part of the high frequency resonator of the present application can be as follows Figure 4As shown, it includes a control unit and a driving unit, and the driving unit includes a signal generator and a power amplifier.

[0048] The signal generator is used to generate a high-frequency signal. The frequency of the original high-frequency signal generated by the signal generator is the same as or similar to the operating frequency of the load (such as an ultrasonic device).

[0049] The power amplifier is used to amplify the signal to be output so as to drive the load (such as ultra-sonic devices).

[0050] The control unit can be a switching power supply, which can output a controllable switching signal. The switching signal can be a periodic signal. The switch-on phase (such as the conduction phase of the switching power supply switch tube) corresponds to a high level, and the corresponding Figure 5 In the first stage, the switch off stage corresponds to the low level, corresponding to Figure 5 The control unit can also control the operating voltage input to the power amplifier to achieve different amplified output powers, which are referred to as first power in this application. In this application, the first power can be understood as the average energy density input to the high-frequency resonator during a drive cycle (a drive cycle consists of a first stage and a second stage). Since the amount of energy is related to power and time, the amount of energy input to the high-frequency resonator during a drive cycle is related to the first power, the duration of the first stage, or its duty cycle.

[0051] The control unit can control the output of the drive unit in at least the following ways:

[0052] The first one: Figure 5 As shown, the original signal of the signal generator is modulated by the switching signal of the control unit, and the modulated output signal is amplified to form the output signal of the driving unit.

[0053] The second type: Figure 6 As shown, the original signal of the signal generator is power amplified, and the power-amplified signal is modulated under the control of the switch signal of the control unit. The modulated signal is the output signal of the driving unit.

[0054] The circuit of the driving part of the high frequency resonator can also be in other forms, or the method of controlling the output signal can also be in other ways, as long as the output Figure 5 or Figure 6 The output signal of the drive unit can be used.

[0055] 8) Conversion rate of acoustic wave energy (or mechanical energy generated by a high-frequency resonator) into kinetic energy of the fluid: In this application, it refers to the conversion rate of the vibration energy (or acoustic energy) of the high-frequency resonator into the kinetic energy of the fluid along the direction of acoustic wave transmission.

[0056] In a typical acoustofluidic scenario, the acoustic radiation generated by the working interface of an ultrasonic device creates a continuous thrust on a localized portion of the liquid, pushing that portion of the liquid at high speed in the direction of the acoustic wave propagation. Simultaneously, this high-speed flow also drives the flow of surrounding liquid, creating an eddy effect (Eckart flow). Furthermore, the acoustic device itself generates heat, which creates thermal convection at the interface between the device and the liquid. Therefore, the fluid (jet) moving in the direction of the acoustic wave propagation can be considered the direct fluid motion caused by the propagation of the acoustic wave in the water, while the eddy currents and thermal convection are secondary effects. From an energy transfer perspective, these secondary fluid effects (eddy currents and thermal convection) reduce the kinetic energy of the jet, hindering the formation of a single, high-speed acoustic beam. Furthermore, the fluid flow velocity is roughly proportional to the sound intensity (applied power), so higher power is often required to drive the fluid at high speed. In acoustofluidic scenarios, tiny ultra-ultrasonic devices, such as bulk acoustic wave chips, are used, typically ranging in size from 0.01 x 0.01 mm² to 1 mm², or even smaller. Since microscale devices often have low power handling capabilities, currently in acoustofluidics scenarios, ultra-ultrasonic devices are mostly driven continuously at low power (milliwatt level, such as 0.1W, 0.2W, etc.). However, continuously driving ultra-ultrasonic devices at higher power will also lead to the accumulation of thermal effects and damage the devices.

[0057] First of all, it should be noted that when the acoustic beam is formed in the present application, it is in a basically laminar state with the surrounding liquid and has a low degree of mixing with the surrounding liquid. This means that there is no eddy current or convection when the acoustic beam is formed, or the eddy current and convection phenomenon is extremely low. This also means that the energy loss of forming eddy current or convection is reduced during energy conversion, and the acoustic beam has a higher conversion rate from acoustic wave energy to kinetic energy of the fluid, and the acoustic beam can reach a faster fluid speed. Among them, you can refer to Figure 2 The continuous frame images of the acoustic beam flow generation process of the present application are multiple frame images of the acoustic beam flow generation process taken every 0.4ms using a high-speed camera when the input power of the high-frequency resonator is 1W. It can be seen that the present application can quickly generate an acoustic beam flow within 0.4ms after power is applied. Figure 3This is a continuous-time synthetic trajectory diagram when the present application generates an acoustic beam flow, which shows a schematic diagram of trajectory synthesis after continuous 4ms high-speed shooting and a schematic diagram of trajectory synthesis after continuous 40ms high-speed shooting. It is explained here that for the 40ms trajectory synthesis, the acoustic beam flow (mainly referring to the portion before it acts on the bottom of the liquid environment) maintains a linear or columnar focus and is not as diffuse as a conventional jet. This indicates that the acoustic beam flow and the surrounding liquid have obvious laminar flow phenomenon. On the other hand, the partial displacement of the particles in the liquid environment corresponds to the trajectory formed by slow movement in the entire liquid environment (the acoustic beam flow is restricted by the bottom of the liquid environment and acts obliquely on the bottom to drive the movement of the liquid environment, causing the particles in the liquid environment to move with it). It can be observed that the direction and length of the particle trajectory in the liquid environment (shorter, indicating slow movement) are significantly different from the direction and length of the acoustic beam flow trajectory (longer, indicating fast speed). This means that the acoustic beam flow and the surrounding liquid (such as the liquid surrounding the acoustic beam flow) have obvious laminar flow phenomenon and do not significantly drive the liquid around the acoustic beam flow to move at high speed, nor do they obviously form high-speed vortices or high-speed convection, and do not cause significant displacement of suspended particles in the liquid layer around the acoustic beam flow.

[0058] In order to form the desired acoustic beam flow, the following issues need to be considered:

[0059] 1) Focused sound waves are needed to increase the velocity of the acoustic fluid to achieve the flow rate of the acoustic beam.

[0060] The high-frequency resonator used in this application has a size of about 0.01*0.01 square millimeters to 1 square millimeter or smaller. This microscale can achieve the desired sound wave focusing effect. The ultra-sonic devices used in some experiments introduced in this application are bulk acoustic wave devices, with a size of Figure 8 As shown, it is approximately 0.01-0.02 square millimeters.

[0061] On the other hand, the device resonant frequency is also related to the device size. The above-mentioned micro-sized device can achieve the operating frequency of 0.5 GHz required by this application.

[0062] 2) The acoustic beam requires sufficient energy to drive, so higher power needs to be input into the ultra-ultrasonic device, but at the same time, it is also necessary to avoid the heat generated by high power acting on the micro-scale ultra-ultrasonic device and damaging the ultra-ultrasonic device.

[0063] Based on this, the present application adopts a first power as the input power, wherein the first power is increased by several times, dozens of times, or even nearly a hundred times compared to the aforementioned low power. The first power is, for example, 0.4W, 0.8W, 4W, 10W, 60W, or even 100W or more of the input power. The magnitude of the first power is sufficient to drive the generation of an acoustic beam flow, wherein the intensity of the acoustic beam flow (e.g., speed, distance, force, etc.) is related to the magnitude of the first power. At the same time, it is also necessary to put the high-frequency resonator into an intermittent working mode, that is, to shorten the time that the device is in the working state (or working stage) to reduce the heat generated by the high input power, or to reduce or avoid the generation of secondary flows (eddy currents and convection).

[0064] Specifically, the intermittent operating mode executes at least one drive cycle, each of which includes a first phase and a second phase. During the first phase, the high-frequency resonator is driven to generate ultrasonic waves of no less than 0.5 GHz using the first power, and during the second phase, driving the high-frequency resonator is stopped. The drive cycle can be in the microsecond (µs) to millisecond (ms) range, for example, the drive cycle can be between 1 µs and 100 ms. The smaller the proportion of the first phase within a drive cycle, the shorter the operating time, the shorter the heat generation time, and the lower the secondary flow effect. Accordingly, the longer the second phase, the longer the heat dissipation time within a drive cycle, and the more completely the generated secondary flow (referring to the weak secondary flow that may be generated in the first phase) dissipates. Therefore, when the drive cycle is a constant value, the smaller the proportion of the first phase, the higher the first power that can be applied. In this case, the temperature of the high-frequency resonator can be controlled to be within a third threshold, and the generation of secondary flow by the high-frequency resonator in the liquid environment can be suppressed. In some embodiments, the first phase may account for no more than 50% of a driving cycle, or last no more than 10 milliseconds.

[0065] 3) Reduce or even avoid the generation of secondary fluid behaviors (eddies and convection).

[0066] Secondary fluid requires more time to accumulate and generate. However, the present application places the high-frequency resonator in intermittent operation mode, shortening the time the device is in operation (or operating phase). This first phase duration is insufficient for secondary fluid generation, or significant secondary fluid generation occurs before the second phase begins, thus reducing the occurrence of secondary fluid. In other words, the first phase duration within a drive cycle is very short, and the second phase begins after this duration has not yet resulted in the generation of secondary fluid, or the generation of secondary fluid is extremely subtle. The shorter the first phase duration and the smaller the proportion of the first phase, the more difficult it is to generate secondary fluid, or the less noticeable it is. In some embodiments, when the ratio of the first phase to the second phase in a drive cycle is 1:1 (i.e., the first phase accounts for 50% of the drive cycle), the first phase can be 0.5 microseconds to 10 milliseconds. In particular, when the first phase lasts between 0.5 and 100 microseconds, virtually no secondary fluid is observed.

[0067] It should also be noted that the generation of secondary fluids requires time to accumulate. High-speed camera observations show that the generation of eddy currents requires the device to remain in a continuous operating state (i.e., the first stage) for at least milliseconds or tens of milliseconds (depending on the drive power), while the generation of thermal convection typically requires the device to remain in a continuous operating state (i.e., the first stage) for at least 100 milliseconds (depending on the drive power). Therefore, by placing the high-frequency resonator in an intermittent operating mode and selecting an appropriate drive cycle and the duration of the first stage, or its proportion within the drive cycle, the present application can effectively control the generation of secondary fluids, and particularly effectively control the generation of thermal convection.

[0068] 4) It is necessary to improve the ability to convert mechanical energy (energy from sound vibration) into fluid kinetic energy, that is, to improve the energy absorption capacity of the fluid and improve the conversion efficiency.

[0069] When a resonator acts on a liquid, using high frequencies can shorten the distance sound waves travel in the liquid, increasing the liquid's ability to absorb energy in a short period of time, improving conversion efficiency, and shortening conversion time. Conversion efficiency refers to the conversion rate of core input energy (i.e., the vibration energy or sound energy of the high-frequency resonator) into kinetic energy of the fluid along the direction of sound wave transmission.

[0070] The present application adopts a high-frequency resonator operating above 0.5 GHz, preferably a high-frequency resonator operating above 1 GHz, and more preferably a high-frequency resonator operating between 2 GHz and 2.5 GHz.

[0071] The specific ideas for realizing the acoustic beam flow in this application will be further introduced in detail below to better understand the solution provided by this application.

[0072] To form the desired high-speed acoustic beam, sufficient energy must first be applied to the localized liquid. This energy rapidly propels the liquid into a high-speed jet, thus forming the desired acoustic beam—the aforementioned microscale columnar high-speed acoustic beam. Therefore, the first issue to be addressed is increasing the energy applied to the localized liquid.

[0073] From a holistic perspective, the acoustic beam generation process involves converting electrical energy into an acoustic field (which can also be understood as a special type of high-frequency vibrational mechanical energy) and then inputting the acoustic field into the fluid field. Therefore, increasing the initial energy input is a direct solution to increasing the energy output of the ultra-ultrasonic device to the liquid. In other words, by increasing the input power of the ultra-ultrasonic device, the energy applied to the local liquid by the ultra-ultrasonic device can be increased to achieve the energy required to form the acoustic beam. However, because microscale devices, measuring approximately 0.01 to 1 square millimeter, often have low power tolerance, as previously mentioned, milliwatt-level input power is often used. Increasing the input power, especially by several times, dozens of times, or even nearly a hundred times, conventionally driving the ultra-ultrasonic device will inevitably lead to increased heating and even burnout. However, the present application places the high-frequency resonator in an intermittent operating mode. Due to the limited duration of the first phase, the heat generated by the ultra-ultrasonic device is limited, and the heat can be rapidly dissipated during the second phase, thereby maintaining the ultra-ultrasonic device within the permissible thermal range. On the other hand, since the present application solution achieves a high efficiency in converting the mechanical energy (or acoustic energy) of high-frequency vibrations into fluid kinetic energy, the heat generation is also extremely low, which in turn is beneficial to increasing the input power of the device.

[0074] Furthermore, as previously described, eddies and thermal convection are secondary effects relative to jet flow. Secondary fluid behavior (i.e., eddies and thermal convection) requires more time to accumulate and form compared to jet flow. However, the present application places the high-frequency resonator in an intermittent operating mode and limits the duration of the first phase (i.e., the device operating time within a drive cycle) to a time insufficient for secondary fluid formation, effectively avoiding or reducing the generation of secondary fluid. Furthermore, the effective avoidance or reduction of subacoustic fluid flow further concentrates the conversion of fluid kinetic energy on generating the acoustic beam, resulting in a higher conversion rate of mechanical energy into kinetic energy of the fluid along the direction of acoustic wave propagation (i.e., the direction of the acoustic beam).

[0075] From a certain perspective, the heat generated by conventional low-frequency resonant devices (such as 20KHz to 100KHz ultrasonic devices) when acting on liquids can be regarded as energy loss in the process of the resonant device converting input energy (electrical energy) into mechanical energy (ultrasound). This loss is presented in the form of heat and can also be called heat loss.

[0076] On the one hand, improving the efficiency and conversion rate of energy transfer from the resonant device to the water can reduce heat loss. As mentioned earlier, when using high-frequency devices to act on liquids, increasing the operating frequency means improving the efficiency and conversion rate of energy transfer to the water. Experimental testing has shown that at operating frequencies above 0.5 GHz, the efficiency and conversion rate of energy transfer to water from the ultra-sonic device meet the requirements, and heat loss (i.e., heat generation) can be maintained within the desired threshold. Further increasing the operating frequency (i.e., the output frequency of the ultra-sonic device) to above 1 GHz will further reduce heat loss, especially when the operating frequency is increased to above 2 GHz, where heat loss is further reduced.

[0077] From another perspective, in the process of converting the input energy (electrical energy) into mechanical energy (ultrasonic) by the above-mentioned ultra-ultrasonic device, the conversion process includes: the first process of injecting electrical energy into the ultra-ultrasonic device, and the second process of converting the energy into mechanical energy (ultrasonic). The first process is the process of transferring electrons to the device, and the second process is the process of converting the mechanical vibration generated by the device into mechanical energy (ultrasonic). Energy loss (heat loss) can be understood as the part of the input electrical energy that is not completely converted into mechanical energy (other energy losses are not considered for the time being). Shortening the time of the first process is equivalent to shortening the power supply time in a driving cycle, thereby reducing the heat loss caused by continuous power supply (such as heat loss caused by the internal resistance of the device). On the other hand, the shortening of the first process time also means a relative increase in the remaining time in a week, thereby providing more time for the heat loss part (i.e., the generated heat) to dissipate from the ultra-ultrasonic device within a week, which is beneficial for the ultra-ultrasonic device to remain within the heating threshold. Based on this, the signal at the input end of the ultra-ultrasonic device is input in a manner modulated by the switching signal, as can be seen in the following figure. Figure 5 or Figure 6 As shown, the signal at the input end of the ultra-ultrasonic device (i.e., the output signal of the driving unit) has a signal duration, and then the input signal is turned off for a period of time, and then the input signal can be continued for a period of time again, thus forming a periodic signal input.

[0078] Based on the above analysis, the power supplied by the switching power supply to the super-ultrasonic device is set to a first power. The magnitude of the first power matches the amount of energy required for the required acoustic beam flow. In addition, the first power is modulated by a periodic switching signal into an input driving unit to drive the super-ultrasonic device to operate. That is, the super-ultrasonic device is driven by the first power in an intermittent working mode. The intermittent working mode includes several driving cycles, each driving cycle includes a first stage and a second stage. In the first stage, the high-frequency resonator is driven to generate super-ultrasonic waves of not less than 0.5 GHz, so that the super-ultrasonic device generates super-ultrasonic waves above 0.5 GHz to act on the liquid environment, generating an acoustic beam flow in the liquid environment. In the second stage, the driving of the super-ultrasonic device is stopped.

[0079] Moreover, as mentioned above, the shortening of the first process time is conducive to the heat dissipation of the super ultrasonic device. Therefore, the pulse width of the high level of the switching signal can be made smaller than the first threshold value, that is, the duration of the first stage within the one driving cycle is made to have a duty cycle within the one driving cycle that is smaller than the first threshold value, or the duration is made to be less than the second threshold value. At this time, the temperature of the super ultrasonic device in the intermittent working mode can be made to be within the third threshold value.

[0080] Moreover, when the intensity of the first power input to the ultra-ultrasonic device is increased, the intensity of the acoustic beam flow can be increased. Furthermore, when the intensity of the first power is increased, if the pulse width of the high level of the switching signal is reduced at the same time (i.e., the duration of the first stage is shortened), the intensity of the first power can be further increased, thereby further increasing the intensity of the acoustic beam flow. Moreover, since the intensity of the first power can be further increased under the condition of reducing the duty cycle or duration of the duration of the first stage within a driving cycle, this can also increase the response speed of the acoustic beam flow generation, that is, it can generate the acoustic beam flow more quickly in response to the driving signal. After testing, the pulse width of the high level of the switching signal (i.e. Figure 5 The signal duration within one driving cycle shown in the figure, that is, the duration of the first stage within one driving cycle, can be shortened to 0.1 microseconds to 1 microsecond, and a power of up to 60W can be applied. At this time, a high-speed acoustic beam flow is basically generated instantly, and the response delay of the generation of the high-speed acoustic beam flow to the driving signal is extremely short, within the order of microseconds.

[0081] Furthermore, based on the characteristics of the ultra-ultrasonic device itself, or through testing (the test can be performed with the ultra-ultrasonic device in a liquid environment), the maximum efficiency of converting electrical energy into mechanical energy of the ultra-ultrasonic device under different durations of the high level of the switching signal, or different duty cycle outputs, can be obtained. For example, when the high-level duty cycle of the switching signal is m1% (corresponding to the switching power supply being in the on stage), the amount converted into different mechanical energies can be measured by applying different powers (i.e., the amount of injected electrical energy), or the amount of heat loss (heat generated by the ultra-ultrasonic device) can be measured to calculate the amount converted into mechanical energy. It can be predicted that, when the switching signal has a high duty cycle of m1%, as the power supplied to the hypersonic device by the switching power supply gradually increases, heat loss increases gradually in small increments (this portion represents normal device operation and heat dissipation). However, as the power gradually increases to a certain point, the incremental heat loss, or heat generation, suddenly increases significantly. This point indicates that within a certain period (T) of the switching signal, the hypersonic device has failed to convert substantially all of the input energy into mechanical energy. The excess unconverted energy is lost as heat, resulting in a significant instantaneous increase in heat loss, which in turn results in a transient high heat generation. The input power corresponding to this point can be considered the input power threshold of the hypersonic device when the switching signal has a high duty cycle of m1%. Based on this method, the input power thresholds for different switching signal high duty cycles of m1%, m2%, m3%, and so on can be obtained. Theoretically, assuming a constant total energy within this period (T), the smaller the switching signal high duty cycle (m1%), i.e., the shorter the switch on phase, the higher the threshold power applied during the high phase of the switching signal.

[0082] On the other hand, when the pulse frequency output by the switching power supply is relatively low, that is, the period T of the switching signal is long, the super ultrasonic device may convert almost all of the input energy into mechanical energy in less than T time. In this case, the power value output by the switching power supply can be increased as described above, or the pulse frequency output by the switching power supply can be increased (that is, the period T of the switching signal can be shortened). Both methods can improve the energy output rate of the switching power supply, and accordingly increase the intensity of the acoustic beam flow acting on the liquid by the super ultrasonic device.

[0083] On the other hand, for ultra-ultrasonic devices, the closer the input pulse frequency (i.e., the signal frequency output by the driver) is to the device's operating frequency (i.e., its natural frequency), the greater the vibration amplitude and energy conversion efficiency of the device when it enters a resonant state. Therefore, the frequency of the signal generator's output signal can be designed based on the device's natural frequency.

[0084] On the other hand, increasing input energy also means that the ultra-sonic device drives an increase in the local liquid velocity. This increase in jet velocity leads to an increase in the Reynolds number. An increase in the Reynolds number itself is detrimental to maintaining laminar flow, or in other words, beam flow. However, in actual experiments and measurements, when sufficient energy is driven to generate a beam, the energy's focus makes the beam diameter orders of magnitude smaller than the increase in jet velocity. The Reynolds number remains sufficiently small to maintain laminar flow with the surrounding liquid, or beam flow. For example, preliminary calculations show that even when the ultra-sonic device input power reaches 60W, the switching signal period is 0.1-0.3 microseconds, and the high-level duty cycle is 50%, the beam velocity reaches 10m / s, and the beam diameter (including the observed width of the surrounding water of varying densities) remains at the 1mm level. The calculated Reynolds number is still small enough to exhibit a clear beam flow.

[0085] In addition, the acoustic beam flow should be controllable. The parameters of the acoustic beam flow that can be controlled include the following:

[0086] a1) The initial jet force, velocity, and jet stroke of the acoustic beam. Since the acoustic beam stroke is related to the velocity or the acoustic beam force, these acoustic beam parameters can be controlled using the same input parameters of the ultrasonic device. For ease of description, the initial jet force, velocity, or jet stroke of the acoustic beam will be represented by the first acoustic beam parameter.

[0087] a2) The diameter of the sound beam.

[0088] The input parameters of the ultra-ultrasonic device, or the parameters of the ultra-ultrasonic device itself, or the environmental parameters that may affect the parameters of the above-mentioned controlled acoustic beam flow include the following:

[0089] b1) Output parameters of the switching power supply: waveform parameters of the switching signal, such as the duration of the switching signal's high level within a drive cycle, the duty cycle of the high level, and the number and location of multiple high levels within a drive cycle; the switching signal's frequency (or period), and the applied power (or amplified power). These waveform parameters, frequency, and power can be fixed or variable within each drive cycle, and the variable values ​​can also vary in a regular pattern. For example, they can be divided into large drive cycles, each of which includes several small drive cycles with different waveform parameters, frequencies, or powers.

[0090] Another example is the waveform of the signal generator, such as rectangular wave (square wave), sawtooth wave, sharp pulse (or called triangle wave), step wave, sine wave, half wave and other signals, the corresponding output signal of the driving unit is modulated into sawtooth wave, sharp pulse (or called triangle wave), step wave, sine wave, half wave and other signals. Figure 7A modulated spike (or triangle) wave is shown.

[0091] Parameter b1 is a controllable parameter, and changes in b1 can be used to control the value of the first beam parameter a1. For example, to enhance the first beam parameter, the applied power can be increased, or the applied power can be increased while shortening the duration of the first phase of the drive cycle (i.e., the high-level duration of the switching signal), or the switching signal frequency can be increased.

[0092] Testing has shown that increasing the applied power increases the beam diameter in parameter a2, but only slightly. This is reflected in the test data below. It's predictable that increasing the first beam parameter will also increase the beam diameter, but only slightly. The first beam parameter has an impact on the beam diameter, but the proportion of the impact is small. Furthermore, based on the analysis of the test data below, the observed beam diameter includes density variations around the beam, and the actual beam diameter remains very small.

[0093] b2) Ultrasonic device parameters (for selection): device type, device shape, device size, device structure, device solid-liquid interface surface structure, and device arrangement for multiple ultrasonic devices. In some embodiments, the arrangement of multiple ultrasonic devices can refer to the arrangement of multiple independent ultrasonic devices, such as arranged in rows, columns, or arrays on the inner wall of a flow channel or container, such as a sidewall, bottom, or top. In other embodiments, the arrangement of multiple ultrasonic devices can refer to the arrangement of multiple ultrasonic devices integrated on a single substrate, such as multiple ultrasonic devices arranged in the above manner on a single substrate, with the positive and negative electrodes of the multiple ultrasonic devices respectively connected to the outwardly facing positive and negative terminals of the substrate. After the multiple ultrasonic devices are integrated on the substrate, they exist as a single independent device. When multiple ultrasonic devices are mentioned in various embodiments of this application, the arrangement of these ultrasonic devices can be either of the two aforementioned arrangements.

[0094] The ultra-ultrasonic device can be polygonal, particularly with an odd number of sides. For example, in one embodiment, it can be a regular pentagon or an unequal-sided pentagon. In some embodiments, the dimensions of the ultra-ultrasonic device (herein referring to radial dimensions, non-thickness dimensions, i.e., device interface dimensions) are approximately 0.01 to 1 square millimeter or less. The size of the ultra-ultrasonic device is negatively correlated with the achievable resonant frequency; therefore, reducing the size can increase the resonant frequency. In other embodiments, the resonant frequency of the ultra-ultrasonic device can be altered by varying the device shape, such as the number of polygonal variables, the angles between adjacent sides, or the lengths of individual sides.

[0095] In some embodiments, the acoustic beam can be oriented perpendicular to the surface of the hypersonic device. For example, when the hypersonic device is a bulk acoustic wave (BAW) device, this is because the piezoelectric constant d33 of the hypersonic device's piezoelectric layer (e.g., an AlN layer) is oriented along the thickness direction. This means the vibration direction of the piezoelectric layer, and therefore the direction of acoustic wave propagation, is perpendicular to the hypersonic device. In other embodiments, the acoustic beam can be oriented at an acute angle to the surface of the hypersonic device. For example, when the hypersonic device is a surface acoustic wave (SAW) device, the acoustic beam direction, and therefore the direction of acoustic wave propagation, can be at an angle of approximately 30 to 50 degrees to the surface of the hypersonic device.

[0096] In some embodiments, the ultra-ultrasonic device is a bulk acoustic wave device operating in a thickness stretching vibration mode. The device is made by growing a thin film layer of piezoelectric material in a vertical direction, and excites vibration by coupling a vertical electric field with the d33 piezoelectric coefficient. In some embodiments, the ultra-ultrasonic device includes an acoustic wave reflecting layer, a bottom electrode layer, a piezoelectric layer, and a top electrode layer, arranged in order from bottom to top. The overlapping region of the bottom electrode layer, the piezoelectric layer, the top electrode layer, and the acoustic wave reflecting layer constitutes the ultra-ultrasonic generation region, and the thickness of the piezoelectric layer can range from approximately 1 nm to 2 μm. The top surface of the ultra-ultrasonic device can be configured on the wall of a cavity or other device within the cavity. The cavity is a liquid environment, and the ultra-ultrasonic device generates the aforementioned high-speed acoustic beam flow within this liquid environment.

[0097] The acoustic beam diameter, corresponding to the aforementioned a2, is related to the intrinsic parameters of the ultra-ultrasonic device. For example, the smaller the size of the ultra-ultrasonic device (referring to the radial dimension or interface dimension), the smaller the acoustic beam diameter. Observations based on the impact of the acoustic beam on target tissue (in a liquid environment, the target tissue is located between 200 and 300 microns from the opposite side of the acoustic beam) show that increasing the power has little effect on the target tissue's impact range. The acoustic beam size generally matches the size of the ultra-ultrasonic device. For example, if a 0.01 square millimeter device is used, the target tissue impact range is also approximately 0.01 square millimeter. Therefore, the acoustic beam diameter is highly correlated with the size of the ultra-ultrasonic device.

[0098] b3) Environmental parameters that may affect the acoustic beam flow include: liquid surface thickness, liquid properties (such as density, viscosity, and liquid acoustic impedance), and the properties and thickness of the liquid in contact with the ultra-ultrasonic device in the case of multi-layer liquids. Since b3 is an environmental parameter that generally does not change during operation, this application briefly analyzes these parameters below.

[0099] In this application, experiments have shown that in a liquid environment dominated by aqueous solution, the acoustic beam will accelerate to its maximum speed between 100 microns and 400 microns, especially between 200 microns and 300 microns, from the interface of the ultra-ultrasonic device. Based on this, when considering the application of the maximum speed of the acoustic beam, the liquid surface thickness and the distance between the ultra-ultrasonic device interface and the target object when the acoustic beam acts on the target object can be designed accordingly. The target object may include liquids, solids, colloids, tissues, etc.

[0100] In addition, the properties of the liquid will be reflected in the resistance to momentum. Therefore, it is speculated that when the density, viscosity coefficient and acoustic impedance of the liquid increase, the position where the acoustic beam accelerates to the maximum speed will be shortened if the driving signal (including device input power, driving cycle, and the proportion of the first stage) remains unchanged.

[0101] Furthermore, when multiple layers of liquid are present, the first layer of liquid in contact with the ultra-sonic device will absorb acoustic energy, or, as described above, resist momentum. This can affect the point at which the acoustic beam in the distant second layer of liquid accelerates to its maximum velocity, or its maximum speed. This characteristic can be exploited by adding a first layer of liquid or adjusting its thickness to adjust the point at which the acoustic beam in the second layer of liquid accelerates to its maximum velocity, or its maximum speed. For example, the density, viscosity, or acoustic impedance of the first layer of liquid can be increased relative to that of the second layer of liquid to reduce the point at which the acoustic beam in the second layer of liquid accelerates to its maximum velocity, or its maximum speed.

[0102] The aforementioned environmental parameters that may affect the acoustic beam flow also, from another perspective, affect the first power required to generate a noticeable acoustic beam flow, such as the level of the first power, the duration of the first and / or second phases of the first power drive cycle, or the duty cycle. That is, depending on the environmental parameters of the acoustic beam flow, the aforementioned parameters related to the first power required to generate the acoustic beam flow will vary.

[0103] Under various environmental parameters, the parameters related to the first power for generating the acoustic beam can be determined experimentally. For example, the desired acoustic beam intensity is first determined, such as the initial velocity (or maximum achievable velocity) or the length (the maximum reachable point corresponding to the maximum velocity), or the beam pressure at a point within the beam's travel. Parameters such as the first power, the size or duty cycle of the first and / or second phases are then adjusted until the desired acoustic beam is observed. Furthermore, since forming an acoustic beam involves parameters such as the first power, the first phase, and / or the second phase, multiple sets of parameters may exist that can achieve an acoustic beam of the desired intensity, such as a first set of parameters (first power p01, first phase t11, second phase t12), a second set of parameters (first power p02, first phase t21, second phase t22), and so on. This discussion focuses solely on achieving an acoustic beam of the desired intensity. Under different sets of parameters, other relevant data of the acoustic beam obtained may be different, such as the diameter of the generated acoustic beam, the heat generated by the ultra-ultrasonic device, the degree of secondary flow phenomenon, etc., and can be further optimized from each set of parameters based on the desired degree of restriction on these other data.

[0104] In addition, this application also proposes some applications of generating acoustic beam flow in a liquid environment, for example, as follows:

[0105] 1) A method for directional high-speed liquid transport, comprising: generating a high-speed acoustic beam based on the aforementioned method for generating an acoustic beam in a liquid environment, wherein the acoustic beam is directed in the direction of directional liquid transport, and transporting the liquid in the form of an acoustic beam.

[0106] In some embodiments, it can be used as a power device for a local liquid to carry out high-speed directional transport of the local liquid. In other embodiments, when different liquids exist in a liquid environment, a local high-speed directional transport of one liquid can be carried out into another liquid. For example, the different liquids are two liquids in a laminar state, or two liquids that are immiscible in themselves, wherein a first layer of liquid is in contact with a super ultrasonic device, and an acoustic beam flow is generated in the first layer of liquid to transport the acoustic beam flow of the first layer of liquid into the second layer of liquid. In some embodiments, the speed or depth of the acoustic beam flow including the first layer of liquid injected into the second layer of liquid can be controlled by controlling the intensity of the acoustic beam flow, such as the maximum speed that the acoustic beam flow can reach, or the position of the maximum speed. The duration of the acoustic beam flow can be controlled to control the duration of the acoustic beam flow of the first layer of liquid injected into the second layer of liquid. In particular, when both the first layer of liquid and the second layer of liquid are continuously transmitted, the duration can be controlled to achieve intermittent injection of the acoustic beam flow generated in the first layer of liquid into the second layer of liquid. In some embodiments, a first layer of liquid can be injected into a second layer of liquid through an acoustic beam flow, so that a reaction between the second layer of liquid and the first layer of liquid can be carried out in the second layer of liquid under the condition of excess of the second layer of liquid. The reaction can be a reaction between two liquids, or a reaction between particles in one liquid (such as particles in the first layer of liquid) and another liquid (such as the second layer of liquid), or a reaction between particles in two liquids, especially a reaction between one liquid (such as the first layer of liquid) or particles therein in an excess of another liquid (such as the second layer of liquid).

[0107] In addition, the amount of the delivered liquid can be controlled by controlling the number (or duration) of consecutive driving cycles including the first stage and the second stage.

[0108] 2) A method for directional high-speed transport of particles in a liquid, comprising: generating a high-speed acoustic beam based on the aforementioned method for generating an acoustic beam in a liquid environment, allowing the transported particles to enter the acoustic beam for directional high-speed transport, the acoustic beam being oriented in the direction of directional transport of the liquid, and transporting the liquid including the particles in the form of an acoustic beam.

[0109] In some embodiments, experimental observations have shown that under the action of the acoustic beam, particles will actively enter the acoustic beam from the liquid environment. For example, one observed phenomenon is that particles will move along the solid-liquid interface of the ultra-ultrasonic device to the point where the solid-liquid interface is facing the acoustic beam, and then be transported out by the acoustic beam.

[0110] Based on this, a method for transporting particles in a liquid can be: the direction of the acoustic beam generated by the ultra-ultrasonic device is directed toward the solution transport direction, for example, consistent with the flow direction of the microchannel, and the particles in the solution are moved to the acoustic beam (or called captured by the acoustic beam), and under the constraint of the acoustic beam, they form a queue along the acoustic beam and are transported at high speed. This method can form a queue-like high-speed transport of large-flux particles, and then, the queue-like particles are transported to the downstream, which facilitates further processing or manipulation of the particles downstream. The further processing or manipulation can be, for example, at least one of the following: detection, capture, offset movement control, screening, etc. Among them, you can refer to Figure 9 A schematic diagram of an embodiment of high-speed transport of particles formed by capturing them through an acoustic beam is shown.

[0111] In some embodiments, such as the above two-liquid scenario, the particles may be located in the first layer of liquid, and the target liquid may be the second layer of liquid. The particles in the first layer of liquid are injected into the second layer of liquid through the acoustic beam flow, so that the particles react with the injected particles in the second layer of liquid under the condition of excess second layer of liquid. Figure 10 A schematic diagram is shown, showing a flow channel comprising a first layer of laminar liquid and a second layer of liquid. The present invention generates an acoustic beam flow to capture particles in the first layer of liquid and inject the beam into the second layer of liquid at high speed under constraint, allowing the particles to react with the second layer of liquid in an excessive environment. For simplicity, the figure does not show the effect of liquid flow on the acoustic beam flow.

[0112] In some embodiments, a particle may be delivered into another substance, such as into a vesicle such as a liposome, or into a cell or muscle tissue or a tissue similar to a cell or muscle, or into subcutaneous tissue.

[0113] In some embodiments, the particles described above may refer to any microscopic particle that is located within a liquid environment, distinguishable from the liquid environment (i.e., insoluble), and capable of movement within the liquid environment. In some embodiments, the particle diameter may range from nanometers to micrometers, and may include cells, molecules, molecular polymers, DNA, and the like.

[0114] 3) In the above-mentioned method for directional high-speed transport of liquid or the method for directional transport of particles in liquid, one or more of the above-mentioned special ultrasonic devices can be set. These special ultrasonic devices can respectively realize their own functions, or they can work together to realize a function based on the design of arrangement position and orientation, such as realizing the turning process during the high-speed transport of liquid or particles, and realizing the high-speed transport of multiple liquids or multiple particles to the same target position to realize high-speed collision.

[0115] 4) Based on the above application of directional high-speed delivery of liquids or particles, it can be further applied to the injection of liquids or particles into the subcutaneous tissue or the like.

[0116] As mentioned above, the diameter of the acoustic beam generated by the present application can be 0.1-1 mm or even smaller, with a diameter of 0.1 mm and the aforementioned 10-100 MPa level, which can meet the needs of needle-free injection.

[0117] In some embodiments, the method is applied to needle-free injection, whereby liquid medicine (such as vaccines, injectable drugs, etc.) is injected into the subcutaneous tissue, or even into the subcutaneous muscle layer, via an acoustic beam flow. In some embodiments, the method can be applied to cosmetic skin care, whereby nutrient solutions or some filler fluids are injected into the subcutaneous tissue via an acoustic beam flow. For example, one or more high-frequency acoustic wave resonators are activated to generate a bulk acoustic wave with a frequency of approximately 0.5 GHz in a liquid environment such as a solution, suspension, or gel, so that the bioactive agent in the liquid environment enters or penetrates the patient's skin. Preferably, the first power input to the high-frequency acoustic wave resonator to generate the bulk acoustic wave is approximately 0.1-500 W, preferably 2-50 W, and more preferably 5-10 W.

[0118] In some embodiments, in the implementation scheme of the injection device used for the above-mentioned injection, the working end of the injection device may have a working cavity with an open end, and a liquid environment may be formed in the working cavity. For example, the working cavity is connected to the drug liquid cavity through a channel or a catheter. The drug liquid cavity and the injection device are integrally arranged or detachably arranged. The working cavity has an interface of the special ultrasonic device, and the sound wave transmission direction of the special ultrasonic device is toward the open end of the working cavity.

[0119] In some embodiments, the distance between the ultra-sonic device interface and the open end of the working cavity can be between 200 and 300 microns, allowing the acoustic beam within the working cavity to exit the working cavity when accelerated to its maximum velocity. In other embodiments, the distance can be designed based on the pressure required for needle-free injection; for example, extending the distance to a distance greater than that required for maximum acceleration can achieve a reduction in pressure. In other embodiments, the pressure reduction can also be achieved by reducing the input power, or by shortening the first stage time while maintaining the same input power.

[0120] In some embodiments, the open end of the working cavity can contact a target object (e.g., skin), thereby sealing the working cavity. In some embodiments, when the ultra-ultrasonic device is not activated and the open end of the working cavity is not in contact with the target object (e.g., skin), the size of the open end of the working cavity can also be designed to prevent the liquid in the working cavity from flowing out due to internal and external pressure differences or liquid surface tension.

[0121] It should be noted here that the size of the ultra-ultrasonic device is microscopic, such as about 0.01 square millimeters to 1 square millimeter, so the diameter of the open end of the working cavity can also be not large, a basic diameter of millimeters is sufficient to form and maintain the above-mentioned liquid surface tension.

[0122] In other embodiments, if there is a scenario in which multiple acoustic beams are generated simultaneously, the open end of the working cavity may have a mesh structure, and a number of special ultrasonic devices may be provided in the working cavity. The direction of the acoustic beam of each special ultrasonic device may be directly facing a mesh hole of the mesh. The mesh structure may use liquid tension to keep the liquid in the working cavity when the special ultrasonic device is not working. The mesh structure may also serve as isolation to maintain the required distance between the contact part of the special ultrasonic device in the working cavity and the target object to be injected.

[0123] 5) Based on the above application of directional high-speed transportation of liquids or particles, it can be further applied to cutting of target objects.

[0124] In some embodiments, a liquid (including liquid containing particles) can be accelerated by an acoustic beam in a manner similar to a "water jet" for cutting a target object, and in particular, the target object can be cut by using an acoustic beam accelerated to or close to the maximum speed. As mentioned above, the maximum speed of the acoustic beam in a liquid environment can reach 10m / s, and the diameter of the acoustic beam is at the micron level. At this time, the pressure acting on the target object is extremely strong, and the target object can be cut based on this. For example, even when the maximum speed of the acoustic beam in a liquid environment is 1m / s at 200-300 microns from the device, the target object can be cut based on this. Figure 8 With the device dimensions shown, and the radial dimensions of the acoustic beam being essentially the same as the device dimensions (0.01-0.02 mm²), the pressure at the location of the highest velocity of the acoustic beam can reach 10 MPa. Under the same conditions, when the power is increased to drive the acoustic beam to a maximum velocity of 10 m / s, the pressure can reach 100 MPa. Furthermore, because the diameter of the acoustic beam generated by this application can be 0.1-1 mm or even smaller, a diameter of 0.1 mm and a pressure of 10-100 MPa can far exceed the pressure requirements for cutting tissues (such as muscle and internal organs) (typically, surgical water jet pressure is approximately 0.5-1 MPa).

[0125] In some embodiments, in the implementation of the cutting device used for the aforementioned cutting, the working end of the cutting device may have an open-ended working chamber, wherein a liquid environment may be formed within the working chamber. For example, the working chamber is connected to a liquid supply device via a channel or conduit, and the liquid supply device and the cutting device are integrally provided or detachably provided. The working chamber includes an interface for a super-ultrasonic device, and the sound wave transmission direction of the super-ultrasonic device is toward the open end of the working chamber. The distance between the super-ultrasonic device interface and the open end of the working chamber may be between 200 and 300 microns, so as to utilize the maximum speed to cut the target object.

[0126] In other embodiments, the application environment of the cutting device itself used for the above-mentioned cutting is in a liquid environment. In this case, the above-mentioned working chamber and liquid supply device can be simplified.

[0127] 6) Based on the above application of directional high-speed transport of liquids or particles, it can be further applied to the scouring, polishing, or stripping of attachments on the surface of the target object.

[0128] In some embodiments, when implementing these applications, the generated acoustic beam can be directed toward the target surface, wherein the acoustic beam and the target surface can be arranged at an angle. In other embodiments, the acoustic beam can be directed toward the target location at different angles during the scouring, polishing, or peeling process.

[0129] Below, some experimental data are listed to verify some of the effects mentioned above (some of the data have been described before). First of all, it should be noted that the width of the acoustic beam described below is based on the width observed by optics. When the acoustic beam is generated, the change in density between the acoustic beam and its surroundings will form different refractive indices, which can be observed. On the other hand, since the observed image includes areas with different surrounding densities, the observed width is wider than the actual width of the acoustic beam. As described before, the width of the acoustic beam is mainly related to the size of the ultra-ultrasonic device. In this experiment, the size of the ultra-ultrasonic device is as follows: Figure 8 As shown, it is estimated that the width of the acoustic beam changes by about 0.1 mm.

[0130] After testing, in a water-based environment, using a 2k-sized (unit: square micrometers, shaped like a regular pentagon) ultra-ultrasonic device, and a switching power supply outputting 10ms / 20ms pulses (with a period of 20ms and a level pulse width of 10ms (i.e., the duration of the signal output by the control drive unit)) to the drive unit, the following results were obtained: when the drive unit was loaded with a power of 4W, the width of the acoustic beam (including the observed width of the surrounding water of different densities) was 0.32mm, and the acoustic beam travel reached 7.2mm; when the drive unit was loaded with a power of 8W, the width of the acoustic beam (including the observed width of the surrounding water of different densities) was 0.46mm, and the acoustic beam travel reached 8.2mm; when the drive unit was loaded with a power of 20W, the width of the acoustic beam (including the observed width of the surrounding water of different densities) was 1mm, and the acoustic beam travel reached 13mm.

[0131] Using the same conditions, the beam velocity was measured at a distance of 1-2 mm from the point of contact with the ultrasonic device. When the driver power was 10 W, the beam velocity reached 0.41 m / s; when the driver power was 16 W, the beam velocity reached 0.7 m / s; and when the driver power was 20 W, the beam velocity reached 1 m / s. Based on the above analysis, the beam velocity is at its maximum between 200 and 300 microns from the point of contact with the ultrasonic device. Therefore, the measurements at 1-2 mm represent a decelerated beam. Calculations indicate that increasing the power could achieve a beam velocity of 10 m / s at this distance.

[0132] Furthermore, under the above conditions, when the driver unit load power is further increased to 30W, the ultra-ultrasonic device maintains a long-term stable operating state, and the intensity of the acoustic beam flow is further improved. Furthermore, when the pulse width of the switching power supply output waveform is shortened to the microsecond level, such as when the switching power supply outputs 40us / 80us pulses, the driver unit load power can be increased to 50W, and the ultra-ultrasonic device maintains a long-term stable operating state. It is also speculated that if the switching power supply outputs 10us / 20us pulses, the driver unit load power can be increased to 60W. If the pulse width ratio is reduced, for example, when the switching power supply outputs 10us / 30us pulses, the driver unit load power can be further increased. Furthermore, by further reducing the pulse width ratio and attempting to load the power to 100W, the ultra-ultrasonic device still maintains a long-term stable operating state.

[0133] It should also be noted that the solution provided by the present application can generate a high-speed cylindrical focused acoustic beam in a liquid environment, and can control the temperature generated by the thermal effect within a desired value, and reduce or avoid the occurrence of secondary flow. During application, it is possible to choose to focus more on temperature control or focus more on suppressing secondary flow, or the weight of both is basically the same, based on the application scenario, or / and the level of the first power applied to the high-frequency resonator in the application. In some embodiments, for example, when particles or fluids are transported at high speed through an acoustic beam in a microchannel, the first power used may be below 0.5W, and the heat generation itself is relatively easy to control within the desired threshold. In this way, more attention can be paid to suppressing secondary flow, and the duration or proportion of the first stage can be adjusted to minimize the occurrence of secondary flow. For example, the duration of the first stage can be shortened to reduce the possibility of secondary flow generation, or / and the duration of the second stage can be prolonged to increase the time for secondary flow dissipation, so that the liquid environment tends to be stable. Such adjustment is also conducive to suppressing the temperature generated by the device. In other embodiments, such as those used in the aforementioned subcutaneous injection or muscle tissue cutting, the first power used is relatively large, such as 20W to 100W, and is more focused on controlling the heat of the device at high power. In this case, the duration or proportion of the first stage can be adjusted with heat control as the priority to achieve temperature control within the desired threshold, such as reducing the duration of the first stage to reduce the heat generation time, or / and extending the duration of the second stage to increase the time for heat dissipation, so that the temperature of the device or the liquid environment in which the device is located is within the desired threshold. Such adjustments are also conducive to suppressing secondary flows. Here, only the adjustment of the duration of the first stage and / or the second stage is taken as an example. In actual applications, the first power can be adjusted together so that the first power can achieve the required intensity of the acoustic beam flow under the above-mentioned suppression of temperature and secondary flows.

[0134] This application also verified the following through experiments:

[0135] 1) Under the conditions that the first power driving the high-frequency resonator is a constant value and the first-stage power supply time and the second-stage time are 1:1, the different first-stage durations (i.e., the device operating time within a driving cycle) are as follows: wherein, the shorter the first-stage duration, the smaller the eddy current effect formed by the high-frequency resonator and the more obvious the acoustic beam flow. It can be measured that when the first-stage duration is lower than a certain value, an acoustic beam flow cannot be formed. This is because the total energy is determined by power and time. If the time is too short, the energy required to generate an acoustic beam flow cannot be achieved. Based on this, the lower limit of the first-stage duration for generating an acoustic beam flow when the first power is a constant value can be measured. It can also be measured that when the first-stage duration is higher than a certain value, a significant eddy current will form. This is because the eddy current effect lags behind the acoustic beam flow. When the first-stage duration reaches or approaches the lag time that causes the eddy current effect, a significant eddy current will form. Therefore, the upper limit of the first-stage duration for generating an acoustic beam flow when the power is a constant value can be measured. This upper limit avoids the formation of significant eddy currents.

[0136] 2) When the first stage time and the second stage time are constant, the higher the first power, the faster the acoustic beam speed.

[0137] The high-frequency resonator has an upper limit for receiving power. Beyond this limit, increases in the first power no longer significantly increase the beam velocity, and exceeding this limit also leads to a significant increase in thermal effects. This is because the first and second phase times (the sum of the first and second phase times is the drive cycle) are constant. When the first power increases above the upper limit of the energy that can be converted into beam flow within that drive cycle, most of the excess energy is converted into thermal effects. Therefore, based on the temperature effect, the upper limit of the first power can be measured when the first and second phase times are constant. Alternatively, the lower limit of the first power that generates beam flow when the first and second phase times are constant can be measured as described in step 1) above.

[0138] 3) Under the conditions of a constant first power and a constant first-stage duration, and provided that a beam can be formed, a longer drive period (i.e., a smaller first-stage duty cycle or a longer second-stage duration) reduces the eddy current effect. A too short drive period can cause eddy currents. This is because a longer drive period increases the interval between two consecutive first-stage times, while a shorter drive period decreases the interval between two first-stage times, making eddy currents more likely to occur.

[0139] 4) The vortex is located near the end of the acoustic beam. When the position of the acoustic beam is at its highest speed or near its vicinity, there is no need to pay too much attention to the vortex.

[0140] 5) The eddy current effect is later than the generation of the acoustic beam, and the thermal effect is later than the eddy current effect. Based on this, the length of the first stage can be controlled to suppress the thermal effect below the threshold, or to suppress the secondary eddy current effect.

[0141] 6) For high-frequency resonators of different sizes, at the same input power, the smaller the size, the higher the acoustic beam intensity and the faster the speed. This reflects that the smaller the device size, the stronger the focusing ability.

[0142] The experimental results of this application can be found in Figure 11 As shown, the vertical axis is the average acoustic beam velocity at 600um from the surface of the high-frequency resonator device, in m / s; the horizontal axis is the power input to the device (see Figure 4 That is, the input power of the input device after power amplification); the high-frequency resonators used are 2k, 5k, 10k, and 20k devices (unit is square microns), among which, Figure 12This is a schematic diagram of the dimensions of the high-frequency resonators used in the experiments of this application. It is a pentagonal device, and the specific dimensions can be found in the figure.

[0143] It should also be noted that, unless otherwise noted, the above-mentioned particle examples are described using aqueous solutions (which may contain other particles). When the solution is other than an organic solution (e.g., oil) or a gel solution, the data mentioned above may vary depending on the properties of the liquid.

[0144] This application also combines experimental data with simulation analysis to further verify the conclusions obtained from the data of this application. Specifically, a COMSOL model of a 5K high-frequency resonator was constructed. In the physical field model, the flow field was 1mm wide and 2mm high, and the high-frequency resonator was located in the middle of the bottom of the flow field. By modifying the volume force generated by the high-frequency resonator, a transient simulation was performed to obtain the maximum acoustic beam velocity (maximum acoustic beam velocity = 50um / time taken for the first beam to reach 50um from the device surface) and the average acoustic beam velocity (average acoustic beam velocity = 600um / time taken for the first beam to reach 600um from the device surface), and compared them with the experimental results. The order of magnitude and growth trend of the maximum and average velocities of the acoustic beam generated by the 5K high-frequency resonator in the simulation results are consistent with the experimental results, which also bidirectionally verifies the accuracy of the experiment and simulation.

[0145] The input power and volume force of the high-frequency resonator can be fitted into an approximately linear relationship, and the relationship between the input power and the maximum velocity and average velocity of the acoustic beam can be obtained as follows: on the one hand, as the power increases, the maximum velocity of the acoustic beam also gradually increases. This is because when the power applied to the device increases, the volume force generated above the device is greater, which can make the acoustic beam produce a higher initial velocity; on the other hand, the growth of the maximum velocity gradually slows down. This is due to the incompressibility of the liquid. The initial velocity of the acoustic beam does not increase indefinitely with the increase of the device power, but grows gradually and slowly and finally stabilizes at a certain value. The part that is not converted into kinetic energy will mostly appear in the form of heat. In particular, when the power increase exceeds a certain value, the heat generated in the first stage time cannot be completely dissipated within the complete cycle composed of the first stage time and the second stage time, and the high-frequency resonator will produce a significant thermal effect.

[0146] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods are not limited to the above embodiments, and can also be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0147] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0148] In addition, the words "first, second, third, etc." or module A, module B, module C and other similar terms in the specification and claims are only used to distinguish similar objects and do not represent a specific ordering of the objects. It can be understood that the specific order or sequence can be interchanged where permitted so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein.

[0149] In the above description, the numbers representing the steps, such as S10, S20, etc., do not necessarily mean that the steps must be executed in this manner. If permitted, the order of the steps can be interchanged or they can be executed simultaneously.

[0150] The term "comprising" as used in the specification and claims should not be construed as limiting to what is listed thereafter; it does not exclude other elements or steps. Thus, it should be interpreted as specifying the presence of the features, integers, steps, or components mentioned, but not excluding the presence or addition of one or more other features, integers, steps, or components, or groups thereof. Thus, the expression "a device comprising means A and B" should not be limited to a device consisting solely of components A and B.

[0151] References in this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Therefore, the phrases "in one embodiment" or "in an embodiment" appearing throughout this specification do not necessarily refer to the same embodiment, but may refer to the same embodiment. Furthermore, in one or more embodiments, the particular features, structures, or characteristics can be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure.

[0152] Note that the above are only preferred embodiments of the present application and the technical principles employed. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments and may include many other equivalent embodiments without departing from the scope of protection of the present application, all of which fall within the scope of protection of the present application.

Claims

1. A method for generating a micro-scale columnar high-speed acoustic beam in a liquid environment, characterized in that: include: Liquid environment; a high-frequency resonator that generates 0.5-30 GHz ultrasonic waves to act on the liquid environment to generate directional fluid motion at the solid-liquid interface along the direction of sound wave propagation in the liquid, wherein the directional fluid motion includes a focused columnar acoustic beam flow; The high-frequency resonator is driven at a first power to operate for at least one driving cycle, each driving cycle comprising a first stage and a second stage, wherein the high-frequency resonator is driven to operate to generate 0.5-30 GHz ultrasonic waves in the first stage, and the high-frequency resonator is stopped from being driven in the second stage; The magnitude of the first power enables the high-frequency resonator to generate the acoustic beam flow in the first stage.

2. The method according to claim 1, characterized in that The duration of the first stage at the first power is less than a second threshold or the duty cycle of the first stage in one driving cycle is less than the first threshold, so that the temperature of the high-frequency resonator is within a third threshold.

3. The method according to claim 1 or 2, characterized in that The duration of the first stage at the first power is less than a second threshold or the duty cycle of the first stage in one driving cycle is less than the first threshold, so as to suppress the high-frequency resonator from generating a secondary flow in the liquid environment.

4. The method according to any one of claims 1 to 3, characterized in that: The acoustic beam flow generated by the high-frequency resonator being driven reaches a maximum speed in the first stage of each driving cycle.

5. The method according to any one of claims 1 to 4, characterized in that: The acoustic beam generated by the high-frequency resonator being driven reaches a maximum velocity at a position between 200 and 300 microns away from the high-frequency resonator.

6. The method according to any one of claims 1 to 5, characterized in that: increasing the intensity of the first power to increase the intensity of the acoustic beam flow, or The duration of the first stage or the duty cycle in a driving cycle is reduced, and the intensity of the first power is increased to increase the intensity of the acoustic beam flow.

7. The method according to any one of claims 1 to 6, characterized in that: Also includes at least one of the following: The area of ​​the acoustic beam generation region is about 10-1000000 μm 2 , preferably about 100-40000 μm 2 , more preferably 1000–10000 μm 2 ; The first power is about 0.1-500W, preferably 2-50W, more preferably 5-15W.

8. A method of directional transportation, characterized in that: include: Generating an acoustic beam flow in a liquid based on the method according to any one of claims 1 to 7, wherein the direction of the acoustic beam flow is the direction of the directional transport; The liquid acted upon by the high-frequency resonator, or the particles in the acted liquid, are directionally transported by the dragging force of the acoustic beam.

9. The method according to claim 8, characterized in that The liquid environment includes one or two layers of liquid, wherein the two layers of liquid include a first layer of liquid in contact with the interface of the high-frequency resonator and a second layer of liquid away from the interface of the high-frequency resonator and in contact with the first layer of liquid; The directional transport includes: moving particles in a direction in the first layer of liquid by using an acoustic beam flow or directionally transporting particles in the first layer of liquid to the second layer of liquid.

10. The method according to claim 8, characterized in that Also included is a target substance, wherein the liquid environment is included between the target substance and the interface of the high-frequency resonator; The directional transport includes: transporting the first layer of liquid or particles in the first layer of liquid in a directional manner to the target substance through an acoustic beam flow.

11. A method for processing a target object, characterized in that: include: The distance between the interface of the high-frequency resonator and the target object is 0.05-10 mm, preferably 0.1-5 mm, and most preferably between about 200-400 microns; An acoustic beam is generated using the method described in any one of claims 1 to 7, and the liquid or particle-containing liquid in the liquid environment is applied to the target object through the acoustic beam to inject or cut the target object with liquid, or to flush, polish, or remove surface attachments from the surface of the target object.

12. The method according to any one of claims 1 to 11, characterized in that: The acoustic beam flow is controlled using one or more of the following parameters: the number of durations of the actuation cycles; duration of the first phase and / or the second phase in the drive cycle; The magnitude of the first power.

Images