Software actuator driven by sound field, preparation method and driving method

Abstract

The invention discloses a sound field driven soft actuator, a preparation method and a driving method, the soft actuator comprises an action component composed of sound field response materials, the sound field response materials are made of flexible resin or silica gel materials, and cavity structures arranged in an array mode are embedded in the sound field response materials; the cavity structure is used for constraining air or bubbles; wherein the sound field response material drives the action component to deform through the acoustic mechanical effect generated by the cavity structure under the stimulation of a sound field, and the deformation comprises at least one of bending, opening and closing, stretching and retracting and torsional deformation. The sound field response material has the advantages of being short in response time, large in deformation, controllable in deformation and stable in structure, and the high-performance sound field response material is provided for the soft robot driven by the sound field.

Description

Technical Field

[0001] The present invention relates to the technical field of soft robots, and particularly to an acoustic field-driven soft actuator, a preparation method, and a driving method. Background Art

[0002] Soft actuators can respond to physical fields and deform, and have the advantages of being soft and yieldable compared with traditional rigid actuators, showing better application potential in safe interaction with humans and adapting to complex environments. For example, a bendable and deformable soft actuator integrated at the end of a guide wire can improve the intervention ability of the guide wire in complex human body cavities. However, existing physically field-driven soft actuators have problems of low biocompatibility and poor responsiveness in deep tissues, resulting in limited applications in biomedicine and medical treatments. For example, magnetically driven soft actuators often need to be doped with magnetic response materials, such as neodymium iron boron microparticles, which have certain biological toxicity; electrically field-driven soft actuators require wires to be connected to external power supply devices, and the long wires and high voltage input pose safety problems when applied to organisms; while the tissue penetration of the optical field is poor, and it is difficult to drive soft actuators in deep tissues. Therefore, it is necessary to develop new field-responsive materials and physical fields to solve the application limitations of current field-responsive soft actuators in the fields of biomedicine and medical treatments.

[0003] The acoustic field has the potential to be used for driving soft actuators due to the inherent excellent biosecurity and deep tissue penetration of sound waves, as well as the ability to apply acoustic mechanical effects without labels and contact to drive objects. Therefore, acoustic field-driven soft actuators have the advantages of biocompatibility, wireless control, and responsiveness in deep tissues, showing great potential in developing safe and effective biomedical and medical tools. However, the current development of acoustic field-driven soft actuators is slow because of the lack of high-performance and stable acoustic field-responsive materials and strong acoustic mechanical effects. For example, soft actuators driven by the thermoacoustic effect principle require a long heating or cooling time (in the order of minutes) to deform; another example is that soft actuators driven by the acoustic streaming effect principle require the field-responsive material to attach bubbles, which are easily damaged under acoustic field stimulation and surrounding environmental interference, resulting in a short service life, unstable deformation, and difficult control of the soft actuator. Summary of the Invention

[0004] In view of the above defects of the prior art, the object of the present invention is to provide an acoustic field-driven soft actuator, which is composed of an acoustic field-responsive material with high performance, long service life and strong acoustic-mechanical effect, and can deform rapidly (in seconds), stably and controllably under the drive of an acoustic field. By programming the acoustic field parameters and the structural parameters of the soft actuator, the diversity and flexible controllability of the deformation mode are realized. Based on the deformation mode of the soft actuator, it is applied to an acoustic field-driven soft robot to solve the application limitations of the current field-responsive soft actuator in the biomedical and medical fields. The present invention brings a new type of soft actuator and its driving principle, method and application to the technical field of soft actuators. To achieve the above object, the technical solution of the present invention includes:

[0005] An acoustic field-driven soft actuator, which comprises:

[0006] An action member composed of an acoustic field-responsive material, the acoustic field-responsive material is made of a flexible resin or silica gel material, and an arrayed cavity structure is embedded therein, and the cavity structure is used to confine air or bubbles;

[0007] Wherein, the acoustic field-responsive material drives the action member to deform through the acoustic-mechanical effect generated by the cavity structure under the stimulation of the acoustic field, and the deformation includes at least one of bending, opening and closing, stretching and twisting deformation.

[0008] A further improvement of the present invention is that the size of the cavity structure is 1 μm to 10 mm; the shape of the cavity structure includes a cylindrical shape, a polygonal column shape and a spherical shape; the cavity structure is a sandwich layer structure, including a film layer - cavity layer - film layer.

[0009] A further improvement of the present invention is that the frequency range of the acoustic field is 100 Hz to 20 MHz.

[0010] A further improvement of the present invention is that the form of the action member includes:

[0011] A strip-shaped or sheet-shaped acoustic field-responsive material in a single piece, as a bending action member;

[0012] Two sheet-shaped acoustic field-responsive materials assembled relatively into a pliers configuration, as an opening and closing action member;

[0013] Multiple sheet-shaped acoustic field-responsive materials assembled into a spring configuration, as a stretching action member;

[0014] Two sheet-shaped acoustic field-responsive materials connected up and down by inclined soft rods, as a twisting deformation action member.

[0015] The present invention also provides a preparation method of an acoustic field-driven soft actuator, which comprises the following steps:

[0016] Prepare an acoustic field response material with a cavity structure, where the cavity structure is formed by a mold injection method or a direct machining method;

[0017] Assemble the acoustic field response material into an actuating member with a target shape to obtain an acoustic field-driven soft actuator.

[0018] A further improvement of the present invention lies in that the process of preparing the cavity structure by the mold injection method includes:

[0019] Prepare a mold with a pattern opposite to the cavity structure, cover the surface of the mold with a resin or silicone material, and peel it off after curing to obtain an acoustic field response material with an open cavity structure; the processing technology of the mold is selected from one of photolithography, 3D printing, two-photon printing, or laser processing;

[0020] Form the cavity structure by sealing the open end of the open cavity structure through a film sealing process.

[0021] A further improvement of the present invention lies in that the process of the film sealing process includes: performing plasma surface treatment on the open cavity structure and the film layer, and then fitting them together to form a sandwich structure including a film layer - cavity layer - film layer.

[0022] A further improvement of the present invention lies in that the direct machining method includes one of photolithography, 3D printing, two-photon printing, or laser processing.

[0023] The present invention also provides a driving method for an acoustic field-driven soft actuator, which is used to drive the above-mentioned acoustic field-driven soft actuator, and includes the following steps:

[0024] Generate an acoustic field through a transducer, and the frequency of the acoustic field is 100 Hz to 20 MHz;

[0025] Apply the acoustic field to the acoustic field response material of the soft actuator, and use the acoustic-mechanical effect generated by the cavity structure to drive the soft actuator to deform.

[0026] A further improvement of the present invention lies in that during the process of driving the soft actuator:

[0027] By changing the position or orientation of the transducer, adjust the direction of the acoustic-mechanical effect, so as to control the bending direction or deformation degree of the soft actuator;

[0028] Control the deformation degree of the soft actuator by adjusting the acoustic field intensity, and the deformation degree increases with the increase of the acoustic field intensity.

[0029] The technical solution provided by the present invention has the following technical effects:

[0030] 1. The present invention provides an acoustic field-driven soft actuator, and also provides a preparation method, a deformation degree control method of the acoustic field-driven soft actuator, and an application in an acoustic field-driven soft robot. The present invention brings a new type of soft actuator and its driving principle, method and application to the technical field of soft actuators, and can guide the development of acoustic field-driven soft actuators and acoustic field-driven soft robots.

[0031] 2. The present invention provides an acoustic field-responsive material, which realizes the acoustic field driving of a soft actuator by using the strong acoustic-mechanical effect generated in the acoustic field stimulation of a cavity structure; the acoustic field-responsive material has the advantages of short response time, large deformation, controllable deformation and stable structure, and provides a high-performance acoustic field-responsive material for an acoustic field-driven soft robot.

[0032] 3. The present invention provides an acoustic field-responsive material with a cavity structure having a sandwich layer, which solves the problems of short residence time and unstable volume of the bubbles trapped by an open cavity structure, and improves the service life and performance stability of an acoustic field-driven soft actuator.

[0033] 4. The present invention provides a deformation mode control principle and method for an acoustic field-responsive actuator, which realizes the acoustic field driving of a soft actuator by using the acoustic-mechanical effect generated in the acoustic field stimulation of a cavity structure; by programming the acoustic field parameters and the soft actuator structure parameters, the diversity and flexible controllability of the deformation mode are realized.

[0034] 5. The transducer for generating an acoustic field provided by the present invention is small in volume and portable; the generated acoustic field has good biocompatibility and deep tissue penetration, and the acoustic field-driven soft actuator provides a safe, effective and easy-to-operate medical soft actuator and soft robot for the field of biomedical applications.

[0035] 6. The acoustic field-driven soft actuator prepared by the present invention has a short response time, good biocompatibility, wireless driving and diverse and controllable deformation modes, and broadens the application scenarios of soft actuators.

[0036] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the drawings to fully understand the purpose, features and effects of the present invention. Description of the Drawings

[0037] Figure 1 The figure shows a schematic diagram of the deformation of the acoustic field-driven soft actuator of the present invention in an acoustic field;

[0038] Figure 2 The figure shows a micrograph of the acoustic field-responsive material;

[0039] Figure 3 It is a schematic diagram of the deformation degree control method of the soft actuator;

[0040] Figure 4 Schematic diagram of a soft actuator applied to a flexible gripper robot;

[0041] Figure 5 Schematic diagram of a soft actuator applied to a swimming robot.

[0042] Wherein: the reference numerals are: 1 - transducer; 2 - sound field; 3 - sound field responsive material; 4 - schematic diagram of deformation caused by primary acoustic radiation force or acoustic streaming effect; 5 - schematic diagram of deformation caused by secondary acoustic radiation force effect; 6 - cavity structure; 7 - film layer; 8 - large-size cavity structure; 9 - small-size cavity structure; 10 - robotic arm. Specific embodiments

[0043] The following specific examples illustrate the embodiments of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0044] As Figure 1 shown, Figure 1 is a schematic diagram of the deformation of a sound field-driven soft actuator in a sound field. In this embodiment, when the transducer 1 is turned on to generate the sound field 2, the sound field responsive material 3 in the soft actuator is subjected to acoustic mechanical effects (including deformation 4 caused by primary acoustic radiation force or acoustic streaming effect, and deformation 5 caused by secondary acoustic radiation force), causing the soft actuator to deform. By assembling the sound field responsive material into an action member with a target shape, under the drive of different acoustic mechanical effects, multi-mode deformation of the sound field-driven soft actuator is achieved, including bending deformation, opening and closing deformation, telescopic deformation, and torsional deformation.

[0045] The transducer is preferably a planar transducer, or a focused transducer, a phased array transducer, a buzzer. The frequency of the sound field generated by the transducer is 100 Hz - 20 MHz. In this embodiment, an 8 kHz planar transducer is preferably used.

[0046] The sound field responsive soft actuator material 3 is composed of resin or silicone material, and has a cavity structure 6 embedded inside for confining air or bubbles. The air or bubbles can generate strong acoustic mechanical effects under the stimulation of the sound field, providing driving force for the soft actuator and causing it to deform.

[0047] The embodiment of the present invention also provides a preparation method for a sound field-driven soft actuator, which includes the following steps:

[0048] The mold is prepared by a processing technique. In this embodiment, the lithography technique is preferably used, or 3D printing, two-photon printing, or laser processing technique. The surface of the mold has a pattern opposite to the cavity structure. In this embodiment, a cylindrical pattern is preferably used, or a polygonal column or spherical pattern. The cylindrical pattern has an array arrangement feature.

[0049] The silicone material polydimethylsiloxane (PDMS) prepolymer is covered on the surface of the mold. After heating and curing to form a shape, it is peeled off from the surface of the mold to obtain the sound field response material 3 with an open cavity structure, as Figure 2 shown.

[0050] In this embodiment, the diameter of the cavity structure is preferably 300 μm, or a cavity structure with a diameter ranging from 1 μm to 10 mm can also be used. The obtained open cavity structure after peeling needs to be subjected to a film sealing treatment to form a cavity structure with a sandwich layer, that is, film layer 7 - cavity layer 6 - film layer 7 (as Figure 2 shown on the right). Compared with the bubbles obtained from the open cavity, the film sealing treatment can preserve the air inside the cavity for a long time, improving the service life and performance stability of the sound field response material.

[0051] Film sealing treatment: The surfaces of the film layer and the open cavity structure are subjected to plasma treatment, and then they are adhered together up and down to obtain a cavity structure with a sandwich layer.

[0052] After the sound field response material is cut and assembled into an actuator member with a target shape, a sound field-driven soft actuator is obtained.

[0053] In addition to the method of preparing the sound field-driven soft actuator by mold injection molding used in this embodiment, it can also be directly prepared by a processing technique, and the processing techniques include lithography, 3D printing, two-photon printing, and laser processing.

[0054] When the sound field-driven soft actuator is stimulated by a sound field, the cavity structure in the sound field response material will respond to the sound field, generating a strong acoustic-mechanical effect, which drives the soft actuator to deform. The acoustic-mechanical effects include acoustic radiation force and acoustic streaming effect, and the acoustic radiation force includes primary acoustic radiation force and secondary acoustic radiation force.

[0055] Specifically, when the transducer is turned on, sound waves are generated from the surface of the transducer and propagate outward, thereby generating a sound field with a gradient sound pressure distribution, that is, the sound pressure is greater closer to the transducer. When the sound field response material is placed in the gradient sound field, the internal cavity will be subjected to the primary acoustic radiation force, and the direction of the force points to the transducer. If the cavity is open, the trapped bubbles generate an acoustic streaming effect under the sound field stimulation. When the bubbles are located on the back side of the soft actuator, the driving force generated by the acoustic streaming effect, and the direction of the force points to the transducer.

[0056] If the cavity structure in the sound field resonates, a secondary sound field can be generated. When two cavity structures are opposite to each other, they are subjected to an attractive secondary acoustic radiation force under the secondary sound field.

[0057] Taking the above acoustic - mechanical effect as the working principle, by reasonably designing the configuration of the moving components of the soft actuator and utilizing different acoustic - mechanical effects, multi - mode deformation of the sound - field - driven soft actuator is achieved. The following details the multi - mode deformation control method of the sound - field - driven soft actuator through specific embodiments, such as Figure 1 . The moving components include the following forms:

[0058] Bending moving component: When the sound - field - responsive material is cut into a single strip or sheet, the prepared driving soft actuator undergoes bending deformation due to the primary acoustic radiation force or acoustic streaming effect exerted on the cavity structure in the sound - field - responsive material, and the bending direction is towards the transducer.

[0059] Opening - closing moving component: When the sound - field - responsive material is cut into two sheets and assembled into a pliers configuration, the prepared driving soft actuator undergoes opening - closing deformation due to the mutual secondary acoustic radiation force exerted between the cavity structures in the sound - field - responsive material.

[0060] Telescopic moving component: When the sound - field - responsive material is cut into multiple sheets and assembled into a spring configuration, the prepared driving soft actuator undergoes telescopic deformation due to the mutual secondary acoustic radiation force exerted between the cavity structures in the sound - field - responsive material.

[0061] Twisting - deformation moving component: When the sound - field - responsive material is cut into two sheets and connected by inclined soft rods up and down, the prepared driving soft actuator undergoes twisting deformation due to the mutual secondary acoustic radiation force exerted between the cavity structures in the sound - field - responsive material.

[0062] When the above - mentioned shapes are combined, the prepared driving soft actuator undergoes composite deformation due to various acoustic - mechanical effects exerted on the cavity structure in the sound - field - responsive material.

[0063] This embodiment also provides a driving method for a sound - field - driven soft actuator, which is used to drive the above - mentioned sound - field - driven soft actuator, and it includes the following steps:

[0064] Generate a sound field through a transducer, and the frequency of the sound field is from 100 Hz to 20 MHz;

[0065] Apply the sound field to the sound - field - responsive material of the soft actuator, and utilize the acoustic - mechanical effect generated by the cavity structure to drive the soft actuator to deform.

[0066] During the process of driving the soft actuator, the morphology and movement of the soft actuator can be changed in the following ways:

[0067] 1. When changing the position of the transducer, by using the principle that the main acoustic radiation force received by the cavity structure is directed towards the transducer, the bending direction control of the sound field-driven soft actuator is achieved. In this embodiment, when the transducer is placed on the left side, the soft actuator bends to the left; when the transducer is placed on the right side, the soft actuator bends to the right. In addition, by gradually changing the position of the transducer, the control of the bending deformation degree of the soft actuator can also be achieved.

[0068] 2. When changing the sound field intensity, by using the change in the magnitude of the acoustic mechanical effect received by the cavity structure, the control of the deformation degree of the sound field-driven soft actuator is achieved. In this embodiment, when the sound field intensity increases, the bending deformation degree of the soft actuator increases.

[0069] 3. When changing the sound field frequency, by using the fact that cavity structures of different sizes have their respective resonance frequencies, the separate control of multiple sound field-driven soft actuators is achieved. In this embodiment, when the sound field frequency is relatively low, the cavity structure 8 with a larger size will resonate to generate a subsonic field, and under the action of the mutually attracting subsonic radiation force, the sound field-driven soft actuator will undergo opening and closing deformation; when the sound field frequency is relatively high, the cavity structure 9 with a smaller size will resonate to generate a subsonic field, and under the action of the mutually attracting subsonic radiation force, the sound field-driven soft actuator will undergo opening and closing deformation;

[0070] 4. By programming multiple sound field parameters, the composite control of the deformation degree of the sound field-driven soft actuator is achieved.

[0071] The deformation modes of the sound field-driven soft actuator are diverse and controllable, and it can be applied to sound field-driven soft robots to achieve different action or motion functions. Here, the applications of the actuator are introduced by taking a flexible gripper and a swimming robot as examples.

[0072] For example, assembling the soft actuator that can undergo opening and closing deformation as shown in Figure 4 at the end of the robotic arm to obtain a flexible gripper robot, which can achieve the function of transporting biological samples. This soft actuator can be realized by using opening and closing action components.

[0073] It is also possible to assemble the soft actuator that can undergo opening and closing deformation as shown in Figure 5 into a bionic fish configuration to obtain a swimming robot, which can achieve the function of swimming motion. This soft actuator is also realized by using opening and closing action components.

[0074] By reasonably utilizing the sound-driven soft actuator, a sound field-driven soft robot that can perform other actions or motion functions is realized.

[0075] The above embodiments are only illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person familiar with this technology can modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical idea disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A sound field driven soft actuator, characterized in that: include: An action member composed of an acoustic field responsive material, wherein the acoustic field responsive material is made of a flexible resin or silicone material and has an arrayed cavity structure embedded therein, wherein the cavity structure is used to bind air or bubbles; Wherein, the acoustic field responsive material drives the action component to deform through the acoustic mechanical effect generated by the cavity structure under the stimulation of the sound field, and the deformation includes at least one of bending, opening and closing, telescopic and torsional deformation.

2. The sound field driven soft actuator according to claim 1, characterized in that: The size of the cavity structure is 1 μm to 10 mm; the shape of the cavity structure includes cylindrical, polygonal and spherical; the cavity structure is a sandwich layer structure, including a membrane layer-cavity layer-membrane layer.

3. The sound field driven soft actuator according to claim 1, characterized in that: The frequency range of the sound field is 100 Hz to 20 MHz.

4. The sound field driven soft actuator according to claim 1, characterized in that: The action components include: A single piece of acoustic field responsive material in the form of a strip or sheet, serving as a bending action member; Two sheets of acoustic field responsive materials that are relatively assembled into a pliers configuration serve as opening and closing action components; A plurality of sheet-shaped acoustic field responsive materials assembled into a spring configuration, serving as a telescopic action member; Two sheet-shaped sound field responsive materials connected up and down by an inclined soft rod serve as torsional deformation action components.

5. A method for preparing a sound field driven soft actuator, characterized in that: The following steps are involved: preparing an acoustic field responsive material comprising a cavity structure, wherein the cavity structure is formed by a mold injection molding method or a direct processing method; The sound field responsive material is assembled into an action component of a target shape to obtain a sound field driven soft actuator.

6. The method for preparing the sound field driven soft actuator according to claim 5, characterized in that: The process of preparing the cavity structure by the mold injection molding method includes: A mold having a pattern opposite to the cavity structure is prepared, a resin or silicone material is covered on the surface of the mold, and after curing, the mold is peeled off to obtain an acoustic field response material containing an open cavity structure; the processing technology of the mold is selected from one of photolithography, 3D printing, two-photon printing or laser processing; The open end of the open cavity structure is subjected to a film sealing process to form the cavity structure.

7. The method for preparing the sound field driven soft actuator according to claim 6, characterized in that: The process of sealing film treatment includes: performing plasma surface treatment on the open cavity structure and the film layer, and then bonding the two together to form a sandwich structure including film layer-cavity layer-film layer.

8. The method for preparing a sound field driven soft actuator according to claim 5, characterized in that: The direct processing method includes one of photolithography, 3D printing, two-photon printing or laser processing.

9. A method for driving a sound field driven soft actuator, for driving the sound field driven soft actuator as claimed in any one of claims 1 to 4, characterized in that: The following steps are involved: Generating a sound field by a transducer, wherein the frequency of the sound field is 100 Hz to 20 MHz; The acoustic field is applied to the acoustic field responsive material of the soft actuator, and the acoustic mechanical effect generated by the cavity structure is used to drive the soft actuator to deform.

10. The driving method of the sound field driven soft actuator according to claim 9, characterized in that: When driving a soft actuator: By changing the position or orientation of the transducer to adjust the direction of the acoustic mechanical effect, the bending direction or deformation degree of the soft actuator can be controlled; The deformation degree of the soft actuator is controlled by adjusting the intensity of the sound field, and the deformation degree increases with the increase of the intensity of the sound field.

Images