Acoustic wave induced cavitation generator

Abstract

The present invention introduces a novel method and apparatus for inducing cavitation in a bulk liquid using a Linear Resonant Actuator (LRA). This LRA is meticulously crafted to produce pronounced vibrations, effectively initiating cavitation within the liquid environment. The design of the LRA stands out for its ability to enhance efficiency, durability, and cost-effectiveness, thereby outperforming conventional cavitation methods. Additionally, the system boasts adaptable features such as continuous flow processing and automated resonance tracking, which are intelligently supported by AI and machine learning algorithms. Moreover, the system is adeptly designed to synergize with advanced technologies like cold plasma and microwave heating, poised to substantially elevate the cavitation process and the efficacy of liquid treatment.

Description

ACOUSTIC WAVE INDUCED CAVITATION GENERATOR

[0001] Mechanical and Bio-System Engineering

[0002] The present invention relates to method and apparatus to cavitate liquids utilizing pulsating acoustic waves at the resonant frequencies of liquid-vessel system. Cavitation is a physical phenomenon that occurs when a liquid experiences a sudden decrease in pressure, leading to the formation of voids or vapor bubbles [1], [2]. The cavitation threshold, also known as the tensile strength of the liquid, is not necessarily equal to its vapor pressure. In fact, the cavitation threshold is generally much higher than the vapor pressure, due to factors such as the presence of gas nuclei, impurities, and surface tension [3].

[0003] The main cause of cavitation inception is pressure variations in the liquid. In hydrodynamic cavitation, pressure changes are induced by geometrical changes in the liquid flow or by the movement of a body in the stationary liquid [4]. In acoustic cavitation, the liquid is subjected to compression and tension as a wave with sufficiently large amplitude passes through it. In some cases, tension is achieved by depositing energy into a limited volume of liquid, as in optical and particle cavitation [5]. Despite the differences in the methods used to induce cavitation, the principles that govern bubble formation and dynamics are the same [6].

[0004] When a cavitation bubble expands and then collapses, it releases a large amount of potential energy. This energy can manifest in unique and potentially destructive effects such as shock waves, hydroxyl radicals, and high-speed fluid jets [7]. Despite the harmful effects of cavitation on hydrodynamic machinery such as pumps and turbines [6], in some applications, these effects can be beneficial and exploited to produce useful effects. Cavitation is commonly used in chemical processes, as well as in biological and medical applications [3]. Due to its antimicrobial effects, cavitation technology is widely used in water and wastewater treatment, as well as in food processing [6], [8].

[0005] Acoustic cavitation technology, particularly ultrasonic cavitation, is a physical method commonly used for the destruction of microorganisms [9]. This method involves the use of piezoelectric transducers

[0010] to produce ultrasound waves

[0011] . However, the efficiency of this method is limited by the low piezoelectric coefficients of the transducers, which make them inefficient at high amplitudes. While the inactivation efficiency of bacteria using this method has been well studied, the limitations of piezoelectric transducers have led researchers to explore alternative methods for inducing cavitation with higher efficiency and greater control

[0012] .

[0006] Although acoustic cavitation technology, such as ultrasonic cavitation, can effectively kill microorganisms, it has drawbacks that prevent its widespread use in industrial applications. These drawbacks are low energy efficiency and high initial and operational costs [6]

[0013] .

[0007] Hydrodynamic cavitation has been proposed as an alternative to acoustic cavitation, as it is capable of operating at an industrial scale

[0014] . However, the intensity of cavitation generated by this method is generally low

[0015] , limiting its effectiveness in certain applications. Additionally, most of the bacterial inactivation observed during hydrodynamic cavitation is due to the temperature increase that occurs during the process, rather than the cavitation itself

[0014] .

[0008] The cavitation phenomenon itself cannot cause a macro scale temperature increase in water, as all reactions involving water produce higher energy products such as hydrogen peroxide, hydrogen, and hydroxyl radicals

[0016] .

[0009] Hydrodynamic cavitation can take on three forms, depending on the inlet liquid velocities: attached steady cavitation, developed unsteady cavitation, and super cavitation. Super cavitation occurs at very low pressures downstream and / or high velocities, resulting in the formation of a large and stable vapor cavity

[0013] . While super cavitation has been found to be effective at killing microbes

[0013] , the high pressure and velocity required can result in increased heat generation in the fluid

[0017]

[0018] . Rising temperature is generally unfavorable as it often signify energy dissipation. This is especially true in certain sectors, like food processing, where elevated temperatures can result in the degradation of essential nutrients

[0019]

[0020] .

[0010] Ultrasonic technology has high energy consumption, which limits its industrial application

[0021] . The energy efficiency of cavitation induced chemistry, either by ultrasonic or hydrodynamic cavitation, is extremely low

[0016] .

[0011] The application of low-frequency sound waves to generate cavitation in acoustic washing machines dates back to the 1950s

[0022] ,

[0023] . Previous studies

[0024] ,

[0025] ,

[0026] , (15), (16),

[0027] have investigated the use of low-frequency pressure fluctuations for cavitation inception. Furthermore, earlier research indicates that cavitation induces pressure fluctuations in the frequency range of 40 to 70 Hz

[0028] ,

[0029] ,

[0030] .

[0012] The object of the invention is to provide a method and apparatus capable of achieving an efficient cavitation inception in liquid by high-amplitude low frequency pulsating sound waves utilizing a resonance effect in the liquid-membrane coupled system.

[0013] The present invention introduces a novel method and apparatus for inducing cavitation in a bulk liquid using a Linear Resonant Actuator (LRA). This LRA is meticulously crafted to produce pronounced vibrations, effectively initiating cavitation within the liquid environment. The design of the LRA stands out for its ability to enhance efficiency, durability, and cost-effectiveness, thereby outperforming conventional cavitation methods. Additionally, the system boasts adaptable features such as continuous flow processing and automated resonance tracking, which are intelligently supported by AI and machine learning algorithms. Moreover, the system is adeptly designed to synergize with advanced technologies like cold plasma and microwave heating, poised to substantially elevate the cavitation process and the efficacy of liquid treatment.

[0014] The technical problem addressed by the present invention is the inefficiency and high operational costs associated with existing cavitation technologies, such as ultrasonic and hydrodynamic cavitation. These methods suffer from low energy efficiency, limited cavitation intensity, and high initial and operational costs, which hinder their industrial applicability, particularly in sectors where temperature control is crucial.

[0015] The solution provided by the present invention is an apparatus and method that utilizes a linear resonance actuator (LRA) to generate high-amplitude, low-frequency pulsating sound waves. This approach leverages the resonance effect within a liquid-membrane coupled system to induce efficient cavitation inception. The invention optimizes the cavitation process by controlling the frequency, amplitude, and waveform of the pressure waves, thereby reducing energy consumption and operational costs.

[0016] The advantageous effects of the invention include:

[0017] Enhanced cavitation efficiency through the use of resonant frequencies.

[0018] Lower energy requirements due to the optimized resonance system, resulting in cost savings.

[0019] Improved mechanical durability and cost-effectiveness compared to other vibration actuators.

[0020] The ability to control cavitation intensity and characteristics through adjustable pressure waves.

[0021] Continuous processing capabilities facilitated by the design of the container with an inlet and outlet.

[0022] These and other objects, features and advantages of the invention will become more apparent upon a reading of the following detailed specification and drawings, in which:

[0023] is a schematic sectional view of an acoustic wave induced cavitation generator method and apparatus in accordance with a first embodiment of the present invention;

[0024] is an exploded schematic view drawing of the resonant electromagnetic actuator, also known as the linear resonant actuator (LRA);

[0025] is a schematic sectional view of the acoustic wave induced cavitation generator method and apparatus of the first embodiment which include an acceleration sensor and feedback control for resonance tracking

[0026] depicts a schematic sectional view of the acoustic wave-induced cavitation generator method and apparatus in the first embodiment, incorporating Back-Electromotive Force (back-EMF) feedback control for sensorless resonance tracking.

[0027] is a schematic sectional view of the acoustic wave-induced cavitation generator method and apparatus in accordance with a second embodiment of the present invention;

[0028] is a schematic sectional view of the cavitation generator method and apparatus in accordance with a third embodiment of the present invention;

[0029] is a schematic sectional view of the acoustic wave induced cavitation generator method and apparatus of the first embodiment which include a vacuum pump;

[0030] is a schematic sectional view of the acoustic wave induced cavitation generator method and apparatus of the forth embodiment of the present invention;

[0031] is a schematic sectional view of the acoustic wave induced cavitation generator method and apparatus of the forth embodiment which include a heating section for pre-heat of liquid;

[0032] presents a schematic sectional view of the fourth embodiment of the acoustic wave-induced cavitation generator, which comprises a method and apparatus, including a mechanism for injecting gas, such as an oxidation gas;

[0033] illustrates a schematic sectional view of the first embodiment of the acoustic wave-induced cavitation generator, which incorporates a plasma generation device;

[0034] Referring to, an acoustic wave-induced cavitation generator method and apparatus is presented in the first embodiment of the current invention. The method and apparatus consists of a tub1and a linear resonance electromagnetic actuator7coupled with bulk liquid3.

[0035] illustrates an exploded schematic view of the resonant electromagnetic actuator7, also known as the linear resonant actuator (LRA)

[0031] , comprising the membrane2, permanent magnet4, spring5, and electromagnet6.

[0036] Referring to, the membrane2, positioned at the lower portion of the tub1, facilitates low-frequency oscillation and is equipped with a permanent magnet4at its back, connected to a spring5, and aligned with an electromagnet6. Electrically connected to the linear resonance electromagnetic actuator7are a power supply8, a motor driver9, and a controller10.

[0037] The linear resonant actuator7is designed for optimal vibration at its resonant frequency, causing the membrane2to vibrate periodically. This generates standing acoustic waves resonant with the bulk liquid3. The resultant standing acoustic waves are potent enough to initiate cavitation phenomenon and bubble collapse in the bulk liquid3.

[0038] The linear resonant actuator7is integrated with the bulk liquid3to create a unified system that leverages the mechanical linear resonance phenomenon for maximum vibration force at a specified frequency with minimal driving energy, exhibiting superior mechanical durability and cost-effectiveness compared to other vibration actuators, including rotary electromagnetic actuators and non-electromagnetic actuators using smart materials

[0031] . The Lorenz force, arising from the interaction between the electromagnetic field caused by the electromagnet6and the magnetic field embedded in the polymer membrane2due to the permanent magnet4, accelerates and decelerates the membrane2, causing oscillation and generating pressure waves in the liquid3.

[0039] The tub1has an upper opening, and the membrane2, situated at the lower portion of the tub1, may have a flat plate shape or other similar shapes.

[0040] The material for the membrane2could be polymer, such as polystyrene (PS), metal like aluminum, or any other substance with high resonance displacement, and a material exhibiting a higher amplitude tonal pitch may also be utilized.

[0041] The motor driver9may be a MOSFET driver, L298N Stepper Motor Driver Controller Board, or any electronic device or circuit capable of managing the power supply to the linear resonance electromagnetic actuator7.

[0042] The controller10could be a multi-function generator (MFG) module, Arduino board, or any other electronic device or circuit capable of generating electric signals with specific and selectable shape, frequency, and amplitude.

[0043] The operation of the acoustic wave-induced cavitation generator method and apparatus starts with the generation of a signal in the controller10, determining the intensity, amplitude, frequency, and waveform of the pressure waves to be generated. The signal is then delivered to the motor driver9, amplifying the signal and delivering the electric current from the power supply8to the linear resonance electromagnetic actuator7. Based on the received electric current, the linear resonance electromagnetic actuator7produces mechanical vibrations, creating pressure waves in the bulk liquid3, leading to cavitation phenomenon.

[0044] The frequency, shape, and amplitude of the pressure waves can be adjusted by changing the signal generated in the controller10and controlling the operation of the motor driver9.

[0045] The consumer electronics sector widely utilizes linear and rotary electromagnetic actuators due to their exceptional mechanical durability and cost-effectiveness compared to other alternatives. Specifically, the resonant electromagnetic actuator7and eccentric rotating mass motor, identified as specialized versions of linear and rotary actuators, are recognized for their success as commercially viable vibration motors. Despite their relatively low power consumption, these motors still produce ample vibration force. In contrast to eccentric rotating mass motors, where vibration force is tied to the frequency element, the resonant electromagnetic actuator7provides controllable force within a specific frequency range. This capability is made possible by its mechanism, which capitalizes on the mechanical linear resonance phenomenon, maximizing vibration force at a predetermined frequency with minimal driving energy. Marketed as the Linear Resonant Actuator (LRA)7, this technology is increasingly integrated into mobile devices, offering swifter response times compared to rotary motors

[0031] .

[0046] To leverage the mechanical resonance of a resonant electromagnetic actuator7, it is essential to either possess prior knowledge of its resonant frequency or have the capability for automatic detection. In, a schematic sectional view illustrates an acoustic wave-induced cavitation generator method and apparatus incorporating an acceleration sensor22and feedback control for resonance tracking. The acceleration sensor22is utilized to identify the natural frequency of the liquid-vessel system. In this scenario, the acceleration sensor22is affixed to tub1containing bulk liquid3. The controller10sends a brief electrical pulse to the motor driver9to activate the linear resonance electromagnetic actuator7, causing it to impact the membrane2once and induce free vibration. The acceleration sensor22reads the frequency of the free vibration of the liquid-vessel system and transmits this data to controller10. The controller10, which can be an Arduino board with the capability to detect the natural frequency using methods such as fast Fourier transform and similar codes, identifies the natural frequency of the system. Once detected, the controller10operates the linear resonance electromagnetic actuator7at the natural frequency of the liquid-vessel system.

[0047] Back-electromotive force (back-EMF) feedback control is a technique employed for sensorless resonance tracking in Linear Resonant Actuator (LRA) motors. In this method, the back-EMF generated during the movement of the LRA motor is utilized as a feedback signal. As the LRA motor vibrates at its resonant frequency, the back-EMF is produced proportionally to the motor's velocity. By monitoring and analyzing the back-EMF signal, the system can dynamically sense the resonance frequency without the need for external sensors. This sensorless approach enables precise tracking and adjustment of the LRA motor's operation to match the natural frequency of the mechanical system it interacts with, ensuring optimal performance and efficiency in various applications, such as haptic feedback systems and vibration motors in electronic devices. This method is well described in different references such as US20200139403 and

[0031] .

[0048] Referring to, a schematic sectional view depicts an acoustic wave-induced cavitation generator method and apparatus that integrates back-EMF feedback control for sensorless resonance tracking. The back-EMF signal, transmitted through path23, is utilized for the resonance tracking of the linear resonance electromagnetic actuator7by employing back-EMF feedback control.

[0049] Hydrophobic surfaces promote liquid separation, enabling the inception of hydrodynamic supercavitation at significantly lower upstream pressures. This results in reduced input energy requirements and increased efficiency for devices utilizing cavitation phenomena

[0032] .

[0050] Referring to, an acoustic wave-induced cavitation generator method and apparatus is presented in accordance with a second embodiment of the present invention. In this configuration, a hydrophobic coating layer11is applied to the surface of membrane2to efficiently induce the supercavitation phenomenon in the liquid medium3. The hydrophobic coating works to reduce the adhesive force between the membrane2surface and the liquid3, promoting the separation of the liquid from the surface and facilitating the occurrence of supercavitation. The remaining components and operational principles of the embodiment shown inare consistent with those described for the first embodiment inof the present invention.

[0051] Referring to, an acoustic wave-induced cavitation generator method and apparatus is depicted in accordance with a third embodiment of the present invention. In this instance, a Van de Graaff generator21as an electrostatic induction machine is employed to generate a hydrophobic layer13attached to membrane2through electrostatic wetting principles, enabling efficient initiation of the supercavitation phenomenon in the liquid medium3.

[0052] The Van de Graaff generator21is consist of a spherical dome15, metal comb16, insulating belt18, insulating supporting column24, upper roller17, lower pulley20, metal comb19, grounded base25.

[0053] The Van de Graaff generator21is used to charge electrical conductive metal coating13and bulk liquid3using connection12and electrical conductive wire14.

[0054] When the Van de Graaff generator21is operational, it imparts an identical electric charge to both the liquid3and the metal surface13, leading to mutual repulsion. Consequently, this diminishes the wetting of the surface, rendering it water-resistant. The hydrophobic nature of the surface13enhances the induction of cavitation phenomenon and bubble collapse in the bulk liquid3.

[0055] The Van de Graaff generator21can be replaced by any other types of the electrostatic generator or electrostatic induction machines.

[0056] In, a schematic sectional view illustrates an acoustic wave-induced cavitation generator method and apparatus featuring a vacuum pump26. The vacuum pump26is employed to decrease the pressure within the tub1, housing the bulk liquid3with a liquid surface27. The intentional reduction of pressure within the tub1to a specified level contributes to lowering the liquid vapor pressure. Consequently, this reduction in vapor pressure leads to a decrease in the cavitation pressure threshold, thereby enhancing the overall efficiency of the cavitation process. The remaining components and operational principles of the embodiment shown inare consistent with those described for the first embodiment inof the present invention.

[0057] In, an acoustic wave-induced cavitation generator method and apparatus is depicted as part of the fourth embodiment of the present invention. This setup incorporates an inlet28and an outlet29to facilitate the continuous flow of liquid within the tub1. Through this integrated design, the acoustic wave-induced cavitation generator method and apparatus is capable of continuous processing. The remaining components and operational principles of the embodiment shown inare consistent with those described for the first embodiment inof the present invention.

[0058] In, a schematic sectional view illustrates a continuous acoustic wave-induced cavitation generator method and apparatus featuring a heating section30connected to the inlet28of the tub1. This heating section is designed for the pre-heating of the liquid intended for processing within the tub1. The method and apparatus is equipped with an inlet31, connection28and an outlet29to enable a continuous flow of liquid within the tub1, forming an integrated system for ongoing operation. The remaining components and operational principles of the embodiment shown inare consistent with those described for the first embodiment inof the present invention.

[0059] In, a schematic sectional view illustrates a acontinuous acoustic wave-induecd cavitation generator method and apparatus including a gas injection section32.

[0060] , a schematic sectional view illustrates an acoustic wave-induced cavitation generator method and apparatus, which incorporates a plasma generation device33.

[0061] Although the preferred embodiment of the invention have been disclosed for illustrative purpose, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claim.Examples

[0062] 1. An LRA-based cavitation system was used to treat wastewater. The system operated at the natural frequency of the liquid-vessel system, resulting in reduction in energy consumption compared to traditional ultrasonic methods.

[0063] 2. A food processing company employed the invention to extract essential oils from botanicals. The controlled cavitation process preserved the nutriants due to constant temperature opertation.

[0064] The present invention is applicable in various industries, including but not limited to:

[0065] Water and wastewater treatment, where efficient microbial inactivation is essential.

[0066] Food processing, where nutrient preservation and temperature control are critical.

[0067] Chemical processing, where controlled cavitation can enhance reaction rates and yields.

[0068] Biomedical applications, such as targeted drug delivery and non-invasive surgery, where precise cavitation control is required.

[0069] This invention presents a significant advancement in cavitation technology, offering a scalable, energy-efficient, and cost-effective solution to the challenges faced by current methods.

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Claims

A method and apparatus for inducing cavitation in a liquid, comprising:(a) A container designed to hold the bulk liquid;(b) A linear resonance actuator (LRA) positioned within or coupled to the container;(c) A bulk liquid contained within the container;(d) Means for operating the LRA to generate a high-amplitude standing acoustic wave within the liquid, the standing wave inducing cavitation through pressure fluctuations;(e) The operation of the LRA may further promote cavitation by:- Generating high-amplitude surface waves (Faraday waves) on the liquid surface; and- disrupting the periodic pattern of the surface waves, facilitating the formation of a liquid jet.(f) The combination of:- The pressure fluctuations from the standing wave;- The entrapment of gaseous bodies beneath the surface due to the oscillating liquid-gas interface and liquid jet formation; and- The pulsations of any entrapped gas bubbles induced by the acoustic wave;Result in intense cavitation.The method and apparatus of claim1, wherein the linear resonance actuator (LRA) comprises:(a) A membrane adapted to vibrate;(b) A permanent magnet positioned relative to the membrane;(c) A spring biasing the membrane; and(d) An electromagnet configured to generate a magnetic field that interacts with the permanent magnet to induce vibration of the membrane.The method and apparatus of claim1, wherein:(a) the linear resonance actuator (LRA) comprises the components as set forth in claim2, and(b) the LRA is configured such that:the membrane is positioned at a lower portion of the container to facilitate low-frequency oscillation;the permanent magnet is affixed to the back of the membrane and connected to a spring, aligning with the electromagnet; andthe LRA is electrically connected to a power supply, a motor driver, and a controller.The method and apparatus of claim3, wherein:(a) the LRA and the bulk liquid are configured as a resonant system optimized to vibrate at the resonant frequency of the LRA;(b) periodic vibration of the LRA membrane generates standing acoustic waves within the liquid that resonate with the bulk liquid, thereby inducing cavitation and subsequent bubble collapse; and(c) the integration of the LRA with the bulk liquid creates a unified resonant system that utilizes mechanical linear resonance to maximize vibration force at a specific frequency with minimal driving energy.The method and apparatus of claim4, wherein the oscillation and pressure wave generation are achieved through:(a) the Lorenz force, acting on the membrane due to the interaction between:the magnetic field generated by the permanent magnet embedded in the membrane, andthe electromagnetic field generated by the electromagnet.(b) This interaction causes the membrane to accelerate and decelerate, resulting in its oscillation and the generation of pressure waves within the liquid, ultimately leading to cavitation.The method and apparatus of claim3, wherein the LRA membrane is formed from:(a) a material selected from the group consisting of:polymers, such as polystyrene;metals, such as aluminum; ormaterials exhibiting high resonance displacement.(b) The membrane shape may be a flat plate or a similar configuration.(c) Alternatively, the membrane material may be chosen based on its ability to achieve a higher amplitude tonal pitch.The method and apparatus of claim3, wherein:(a) the LRA is electrically connected to a driver circuit configured to manage the power supply to the LRA. Examples of suitable driver circuits include, but are not limited to, MOSFET drivers and L298N stepper motor driver controller boards.(b) the driver circuit is controlled by a controller that generates electrical signals with selectable shape, frequency, and amplitude. Examples of suitable controllers include, but are not limited to, multi-function generator (MFG) modules and Arduino boards.An embodiment of the method as recited in claim7, comprising:a) Generating a control signal within the controller, which is ascertainable through manual or automated methods, including but not limited to AI and machine learning techniques, and which defines:The intensity (amplitude) of the pressure waves;The frequency of the pressure waves, selected to be in resonance with the natural frequency of the coupled liquid-membrane system, and capable of inducing a violent surface wave that leads to a liquid jet;the waveform of the pressure waves.b) Transmitting the control signal to the driver circuit.c) Amplifying the control signal within the driver circuit and providing power from the power supply to the Linear Resonant Actuator (LRA) based on the amplified control signal.d) Generating mechanical vibrations in the membrane by the LRA, in response to the power from the driver circuit, which in turn generate pressure waves within the bulk liquid and initiate cavitation.The method of claim8, wherein the control signal is adjustable to modify the characteristics of the pressure waves. By adjusting the control signal in the controller and operating the driver circuit accordingly, the following properties of the pressure waves can be manipulated:Frequency: The controller can be programmed to generate control signals with different frequencies, allowing for precise adjustment to achieve resonance with the coupled liquid-membrane system.Waveform: The controller can be configured to generate control signals with various waveforms, influencing the shape of the pressure waves in the liquid.Amplitude (Intensity): The control signal strength can be adjusted by the controller, ultimately affecting the intensity (amplitude) of the generated pressure waves.The method and apparatus of claim1, further comprising:(a) a container designed to hold the liquid, wherein the container includes:an inlet for introducing bulk liquid into the container; andan outlet for removing liquid from the container.(b) wherein the combination of the inlet, outlet, and the method of claim1enables continuous liquid flow through the container during cavitation, thereby improving processing efficiency.The method and apparatus of claim1, further comprising:(a) sensorless resonance tracking implemented through back-electromotive force (back-EMF) feedback control; and(b) the back-EMF feedback control system configured to:calibrate the operation of the linear resonance actuator (LRA) to achieve resonance with one of the natural frequencies of the coupled liquid-membrane system, andoptimize the driving signal to promote the formation of violent surface waves and a liquid jet.The method and apparatus of claim1, wherein the membrane further comprises:(a) a hydrophobic coating layer applied to a surface of the membrane.(b) the hydrophobic coating layer reduces adhesive forces between the liquid and the membrane, thereby facilitating liquid separation and enhancing the formation of supercavitation within the bulk liquid.(c) optionally, the hydrophobic coating layer can be applied in a striped pattern to further promote the separation of water from the membrane surface during membrane oscillation.A method for enhancing cavitation in a liquid, comprising:(a) providing an object adapted to oscillate in the liquid, wherein the object can be, for example, an ultrasonic device probe;(b) applying a hydrophobic coating to a surface of the object; and(c) oscillating the object in the liquid, wherein the hydrophobic coating reduces adhesive forces between the object's surface and the liquid, thereby facilitating liquid separation and promoting cavitation.The method and apparatus of claim1, further comprising:(a) a Van de Graaff generator configured as an electrostatic induction machine;(b) a hydrophobic layer formed on the membrane of the linear resonance actuator (LRA) using the Van de Graaff generator. The formation of the hydrophobic layer utilizes the principles of electrostatic wetting.(c) the LRA as described in claim2.(d) a bulk liquid in which the LRA with the hydrophobic membrane is immersed.The method and apparatus of claim14, wherein the Van de Graaff generator is further configured to(a) induce a charge on an electrically conductive metal coating disposed on the membrane of the linear resonance actuator (LRA).(b) the Van de Graaff generator achieves the charge induction through a connection to the electrically conductive metal coating via an electrically conductive wire.The method and apparatus of claim14, wherein:(a) during operation of the Van de Graff generator, the generator induces an electric charge on:the electrically conductive metal coating disposed on the membrane of the linear resonance actuator (LRA); andthe bulk liquid.(b) the induced charges, however, may not necessarily be identical.(c) the charge differential between the metal coating and the liquid can contribute to:reduced surface wetting of the membrane; andfacilitated liquid separation during membrane oscillation, leads to supercavitation.The method and apparatus of claim14, wherein the hydrophobic layer formed on the membrane:(a) enhances the initiation and growth of cavitation bubbles in the bulk liquid due to its hydrophobic properties.(b) the cavitation bubble collapse is also indirectly influenced by the presence of the hydrophobic layer.The cavitation generator system and technique of claim14, wherein the Van de Graaff generator is replaceable with other types of electrostatic generators or electrostatic induction machines.The method and apparatus of claim14, further comprising a cavitation generator system suitable for use with various food liquids, such as water, milk, fruit juice, and others.The method and apparatus of claim1, further comprising:(a) a vacuum pump configured to reduce the pressure within the container holding the bulk liquid.(b) the reduced pressure in the container, achieved by the vacuum pump, lowers the liquid's vapor pressure. This decrease in vapor pressure reduces the cavitation threshold, thereby promoting more efficient cavitation within the bulk liquid.The method and apparatus as described in claim10, further comprising:(a) A heating section located upstream of the container's inlet, which may be a basic heating element or a microwave system integrated with a liquid chamber section, designed to improve the device's output efficiency by enhancing heat and mass transfer efficiencies.(b) The heating section's role is to pre-heat the bulk liquid before its entry into the container, or, in the case of microwave heating, to function concurrently with the entire system.(c) The pre-heated liquid or simultaneous heating theoretically increases the efficiency of cavitation within the container by reducing the liquid's vapor pressure.The method and apparatus of claim10, further comprising:(a) A gas injection section positioned upstream of the inlet of the container.(b) The gas injection section is configured to introduce a gas into the bulk liquid before it enters the container.(c) The introduction of gas bubbles is intended to amplify cavitation nucleation, thereby boosting the overall efficiency of cavitation.A method for cavitational treatment of liquids, comprising:(a) the elements of claim1, for generating cavitation within a bulk liquid;(b) additionally comprising:- a cold plasma generation mechanism, positioned near the liquid surface; and-a linear resonance electromagnetic actuator (LRA), configured to generate a high-amplitude standing acoustic wave within the liquid.(c) wherein the interaction between the cold plasma and the high-amplitude standing acoustic wave:- disrupt the periodic pattern of the surface waves (Faraday waves);- induce the formation of fast liquid jets at the liquid-plasma interface; and- create a violently oscillating plasma-liquid interface, potentially leading to the entrainment of plasma bodies below the liquid's surface.(d) wherein the entrained plasma bodies, further enhance:- plasma diffusion within the liquid; and- cavitation throughout the liquid volume, potentially improving overall system efficiency.

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