Multi-dimensional vibration platform with four-sandwich type piezoelectric actuators uniformly distributed on periphery and arranged in coplanar manner and excitation method

Abstract

The invention discloses a multi-dimensional vibration platform with four sandwich type piezoelectric actuators uniformly distributed on the periphery and arranged in a coplanar manner and an excitation method, relates to the field of high-frequency vibration engineering and micro-nano control, and solves the problems that the axis of the existing piezoelectric actuator is generally perpendicular to the plane of the platform, namely along the X axis, so that the structure is not flat, Y / Z-direction translation must be realized depending on longitudinal vibration, and the working efficiency is low. And the potential of the bending vibration mode in multi-degree-of-freedom excitation cannot be brought into full play. The platform comprises a tail end platform body, four flexible hinges and four actuating units, the four actuating units are symmetrically distributed on the outer edge of the tail end platform body at equal intervals by 90 degrees, the vibration axes of the actuating units are located in the same horizontal plane, and the X-Y plane, the Y-Z plane and the Z-X plane of the actuating units are symmetrical. The platform excites all six degrees of freedom through a bending vibration mode, and longitudinal vibration is only used as a selectable enhancement path of Y / Z-direction translation. The flexible hinge is connected with the tail end platform and the amplitude-change pole, transmits multidirectional bending deformation and inhibits unexpected rigid body displacement. The method is suitable for the fields of precise micromachining, micro-robots, biological microoperation and the like.

Description

A multidimensional vibration platform and excitation method for a four-sandwich piezoelectric actuator with uniformly distributed coplanar arrangement on all four sides. Technical Field

[0001] This invention relates to the fields of high-frequency vibration engineering and micro-nano manipulation technology, specifically to a multidimensional vibration platform and excitation method with a four-sandwich piezoelectric actuator arranged in a coplanar manner around its four sides. Background Technology

[0002] In existing technologies, multidimensional vibration platforms based on piezoelectric ceramics are widely used in micromanipulation and active vibration suppression systems. Traditional solutions often employ single or dual-actuator structures, achieving finite degree-of-freedom output through the coupling of longitudinal and bending vibration modes. Although some studies have introduced three or four actuators to expand the degrees of freedom, such as triangular or rectangular layouts, the following problems still exist: structural asymmetry leads to severe parasitic modes, making the motion trajectory prone to distortion; inconsistent axial heights, such as traditional "sandwich" structures stacked along the axis, result in a large overall platform thickness, making it difficult to integrate into space-constrained systems; translational output relies on longitudinal vibration modes, but longitudinal vibration has high frequencies, small displacements, and is easily coupled with bending vibration modes, affecting decoupling performance; existing symmetrical designs mostly only satisfy mirror symmetry or single central symmetry, lacking simultaneous symmetry about three mutually orthogonal planes XY, YZ, and ZX, limiting the full degree-of-freedom decoupling capability. Although "four-sandwich" structures have been developed to improve symmetry, their actuator axes are typically perpendicular to the platform plane, i.e., along the X-axis, resulting in a non-flat structure. Furthermore, they rely on longitudinal vibration to achieve Y / Z-axis translation, failing to fully utilize the potential of bending vibration modes in multi-degree-of-freedom excitation. Therefore, there is an urgent need for a novel flattened multi-dimensional vibration platform with coplanar actuator axes, evenly distributed on all four sides, capable of achieving six-degree-of-freedom output solely through bending vibration, and possessing tri-orthogonal symmetry. Summary of the Invention

[0003] This invention addresses the shortcomings of existing piezoelectric ceramic multidimensional vibration platforms. While some attempts have been made to improve symmetry using a "four-sandwich" structure, the actuator axes are typically perpendicular to the platform plane (along the X-axis), resulting in a non-flat structure. Furthermore, these platforms rely on longitudinal vibration for Y / Z-axis translation, failing to fully utilize the potential of bending vibration modes in multi-degree-of-freedom excitation. Therefore, a novel flattened multidimensional vibration platform is urgently needed, featuring coplanar actuator axes, uniform distribution around the perimeter, six-degree-of-freedom output via bending vibration alone, and tri-orthogonal symmetry. To this end, this invention proposes a four-sandwich piezoelectric actuator with a coplanar arrangement around the perimeter and an excitation method. "Uniformly distributed around the perimeter" means that four actuator units are symmetrically distributed around the outer edge of the end platform, with adjacent units forming a 90-degree angle, creating an orthogonal symmetrical layout. "Coplanar" means that the vibration axes of all actuator units lie in the same horizontal plane, preferably the YZ plane. The platform as a whole is symmetrical about three mutually perpendicular coordinate planes: XY, YZ, and ZX. With this configuration, all six degrees of freedom can be excited using only the bending mode, while the longitudinal mode serves as an optional enhancement path for Y / Z translation, significantly improving decoupling and structural compactness.

[0004] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: Solution 1: The present invention proposes a four-sandwich piezoelectric actuator with a coplanar arrangement on all four sides, the vibration platform including an end platform, four flexible hinges and four actuation units; the four actuation units are evenly distributed around the outer edge of the end platform, arranged orthogonally and symmetrically at 90-degree intervals, and the vibration axes of each actuation unit are located in the same horizontal plane, forming a completely flattened overall configuration; each actuation unit includes at least an amplitude transformer, a piezoelectric actuator, an end cap and a first bolt; the amplitude transformer is a variable cross-section rod with parallel end faces, an internal threaded hole at the thick end and a flexible hinge connected at the thin end; the piezoelectric actuator has parallel end faces and an axial through hole; Both the amplitude transformer and the piezoelectric actuator are circumferentially equipped with brackets for mounting and fixing, enabling efficient coupling of the overall constraint and vibration energy of the vibration platform. The end cap has an axial through hole, which is axially pre-tightened with the piezoelectric actuator and the amplitude transformer via a first bolt, with the axes of the three components collinear. The first bolt is screwed into the threaded hole at the coarse end of the amplitude transformer to provide a stable pre-tightening force, ensuring that the piezoelectric ceramic is always under compressive stress. One end of the flexible hinge is connected to the outer edge of the end platform, and the other end is connected to the thin end of the amplitude transformer. The flexible hinge is omnidirectionally symmetrical or biaxially symmetrical, used to transmit multi-directional bending deformation while suppressing undesirable rigid body displacement. The four actuation units are fixed to the same reference plane and have the same height via brackets, achieving an ultra-thin and flat design.

[0005] Furthermore, a preferred embodiment is provided, wherein the end platform is a disc-shaped structure with biaxial symmetry and central symmetry, that is, triple orthogonal symmetry in the XY plane, YZ plane and ZX plane.

[0006] Furthermore, a preferred embodiment is provided in which the shape of the end platform is any one of a square, a circle, a regular octagon, a cross, or a regular polygon with rounded corners.

[0007] Furthermore, a preferred embodiment is provided, wherein the piezoelectric actuator includes any combination of a longitudinal vibrating ceramic group and two mutually orthogonal bending vibrating ceramic groups, each ceramic group having a driving electrode and a grounding electrode, supporting multimodal excitation or cooperative excitation.

[0008] Furthermore, a preferred embodiment is provided in which the two mutually orthogonal bending ceramic groups are used to excite bending vibrations about their local coordinate systems Y1 axis and Z1 axis, respectively.

[0009] Furthermore, a preferred embodiment is provided in which the longitudinal vibration ceramic assembly is an optional configuration that is enabled when high stiffness or high frequency response is required for X / Y direction translation.

[0010] Furthermore, a preferred embodiment is provided, wherein the piezoelectric actuator is any structural form of stacked type, patch type, piezoelectric tube type, or any combination thereof, to match different displacement stroke, frequency response characteristics, and load capacity requirements.

[0011] Furthermore, a preferred embodiment is provided in which the connection between the flexible hinge and the end platform and the amplitude rod is achieved by threaded fastening, adhesive bonding, welding or integral molding process.

[0012] Furthermore, a preferred embodiment is provided in which the vibration platform is externally installed and fixed via an amplitude transformer bracket, a piezoelectric actuator bracket, or a combination of both.

[0013] Scheme 2: An excitation method for a four-cage piezoelectric actuator with a coplanar arrangement around its four sides, the method being based on the four-cage piezoelectric actuator with a coplanar arrangement around its four sides multidimensional vibration platform described in Scheme 1. The method includes: rotational vibration of the end platform around the Z-axis: excited by applying an anti-phase signal to the local bending ceramic groups of two pairs of diagonally opposite actuators with axes parallel to the Y-axis around the Y1-axis, with the frequency matching the bending resonance mode; rotational vibration of the end platform around the Y-axis: excited by applying an anti-phase signal to the local bending ceramic groups of two pairs of diagonally opposite actuators with axes parallel to the Z-axis around the Y1-axis, with the frequency matching the bending resonance mode; rotational vibration of the end platform around the X-axis: excited by applying the same signal to the local bending ceramic groups of all actuators around the Z1-axis, with the frequency matching the bending resonance mode; and rotational vibration of the end platform along the X-axis. Translational vibration of the end platform: Excitation is achieved when the same signal is applied to the local bending ceramic groups of all actuation units around the Y1 axis, and the frequency matches the bending resonance mode; Translational vibration of the end platform along the Y axis: Excitation is achieved when the reverse signal is applied to the local bending ceramic groups of two pairs of actuation units with axes parallel to the Z axis around the Z1 axis, and the frequency matches the bending resonance mode; and excitation is achieved when the reverse signal is applied to the local longitudinal ceramic groups of two pairs of actuation units with axes parallel to the Y axis around the Z1 axis, and the frequency matches the longitudinal resonance mode; Translational vibration of the end platform along the Z axis: Excitation is achieved when the reverse signal is applied to the local bending ceramic groups of two pairs of actuation units with axes parallel to the Y axis around the Z1 axis, and the frequency matches the bending resonance mode; and excitation is achieved when the reverse signal is applied to the local longitudinal ceramic groups of two pairs of actuation units with axes parallel to the Z axis around the Z1 axis, and the frequency matches the longitudinal resonance mode.

[0014] The advantages of this invention are as follows: The four-cage piezoelectric actuators of this invention, arranged in a coplanar configuration around the perimeter, form a multidimensional vibration platform and excitation method that achieves flattened, six-degree-of-freedom high-frequency vibration output. By arranging the axes of the four actuators in the same horizontal plane and distributing them at 90-degree intervals around the perimeter, the entire platform maintains a consistent height and eliminates axial stacking, significantly reducing the overall thickness and achieving an ultra-thin, flattened design. This configuration is particularly suitable for space-constrained microsystem integration, such as microrobots and chip-level manufacturing platforms, while still being able to excite all six degrees of freedom (3 translations + 3 rotations) through pure bending vibration modes. This overcomes the bottleneck of traditional vertically stacked structures, which struggle to balance compactness and full-degree-of-freedom output.

[0015] The four-sandwich piezoelectric actuator of this invention, with its coplanar arrangement on all four sides, forms a multidimensional vibration platform and excitation method that possesses tri-orthogonal symmetry, fundamentally suppressing parasitic modes and cross-coupling. The platform as a whole is symmetrical about three mutually perpendicular coordinate planes: XY, YZ, and ZX. The end platform adopts a biaxial mirror + centrally symmetrical geometry, such as a square or circle, with strictly symmetrically distributed actuation units. This tri-orthogonal symmetry ensures that when any degree of freedom is excited, inertial forces and torques in non-target directions are symmetrically canceled out, significantly reducing motion coupling and greatly improving the independent controllability of each degree of freedom, providing a high decoupling basis for precision control.

[0016] This invention discloses a four-sandwich piezoelectric actuator with a coplanar arrangement of uniformly distributed vibration modes on all four sides, and a corresponding multidimensional vibration platform and excitation method. The platform primarily utilizes bending vibration modes to achieve efficient, large-stroke, and low-frequency response multidimensional excitation. Unlike traditional schemes that rely on high-frequency, small-displacement longitudinal vibration modes to drive Y / Z-axis translation, this invention mainly utilizes bending vibration modes to complete all six degrees of freedom output. Bending vibration has advantages such as large displacement amplitude, moderate frequency, and ease of matching with flexible hinges. Combined with a symmetrical layout, it can accurately generate pure translational or pure rotational motion, avoiding trajectory distortion caused by longitudinal-bending mode coupling, and improving dynamic response quality and control accuracy.

[0017] The present invention discloses a four-cage piezoelectric actuator with a coplanar arrangement on all four sides, forming a multidimensional vibration platform and excitation method. This platform offers flexible excitation options, supporting multimodal collaboration and redundant design. Each actuator unit integrates a longitudinal vibration ceramic group and two orthogonal bending vibration ceramic groups. It can achieve the six-degree-of-freedom master mode through a pure bending vibration path, or, when higher stiffness or higher frequency response is required, activate longitudinal vibration as an auxiliary mode to enhance Y / Z-axis translation. This redundant excitation strategy enhances system adaptability. Furthermore, by adjusting the phase and frequency of each ceramic group, only four actuators are needed to independently control all six degrees of freedom without increasing hardware complexity.

[0018] The present invention discloses a four-cage piezoelectric actuator with a coplanar arrangement on all four sides, forming a multidimensional vibration platform and excitation method. The platform exhibits a highly symmetrical and modular structure with balanced stiffness and strong stability. The four actuator units are arranged in a rectangular apex-centered symmetrical layout, ensuring complete force / torque excitation with no eccentric components. Combined with omnidirectional symmetrical flexible hinges and coplanar mounting brackets, the platform maintains excellent structural stiffness and dynamic stability under high-frequency vibration, effectively resisting external disturbances and making it suitable for precision operations under long-term, high-load conditions.

[0019] The present invention discloses a four-cage piezoelectric actuator with a coplanar arrangement on all four sides, a multidimensional vibration platform and excitation method, which features reliable pre-tightening, compact assembly and high energy utilization. The piezoelectric actuator, end cover and amplitude transformer are pre-tightened axially through the first bolt inside each actuation unit to ensure that the piezoelectric ceramic is always under compressive stress and to prevent tensile failure. All components are fixed in the same reference plane to reduce vibration energy leakage to the base and improve electromechanical conversion efficiency and long-term operational reliability.

[0020] The four-cage piezoelectric actuators of this invention, arranged in a coplanar manner around the perimeter, form a multidimensional vibration platform and excitation method. This invention is highly versatile and easy to customize and expand. The end platform shape can be round, square, octagonal, etc., and the piezoelectric actuators can be stacked, patched, or piezoelectric tubes. The connection process can be threaded, glued, or integrally molded, all of which can be flexibly configured to meet the requirements of different application scenarios for stroke, frequency, load, and size. It is widely applicable to fields such as micro-nano fabrication, ultrasound-assisted manufacturing, cell manipulation, active vibration isolation, and micro-robotics.

[0021] In summary, this invention, through a four-sandwich actuation architecture with four coplanar sides and a flat platform design with three orthogonal symmetrical surfaces, achieves fully decoupled six-degree-of-freedom high-frequency vibration output dominated by bending vibration while ensuring an ultra-thin profile. It solves the key problems of traditional multidimensional piezoelectric platforms, such as structural thickness, strong coupling, and severe modal interference, and provides an innovative technical platform for the next generation of highly integrated and high-precision micro-operating systems.

[0022] This invention is also applicable to high-symmetry, low-coupling, flattened multidimensional vibration platforms for six-degree-of-freedom high-frequency microscale motion control, and is particularly suitable for applications with stringent requirements for structural compactness, motion decoupling, and dynamic stability, such as precision micromachining, ultrasonic-assisted manufacturing, and microrobots. Attached Figure Description

[0023] Figure 1 is a schematic diagram of the structure of the multidimensional vibration platform with a four-sandwich piezoelectric actuator arranged in a coplanar manner around its four sides, as described in Embodiment 1.

[0024] Figure 2 is an exploded view of the four-sandwich piezoelectric actuators of the first embodiment, which are arranged in a coplanar manner around the perimeter.

[0025] Figure 3 is a full cross-sectional schematic diagram of the multidimensional vibration platform with four sandwich piezoelectric actuators arranged in a coplanar manner around them, as described in Embodiment 1.

[0026] Figure 4 is a vibration diagram of the end platform of the multidimensional vibration platform of the four-sandwich piezoelectric actuator with coplanar arrangement around the four sides as described in Embodiment 2, rotating around the Z-axis.

[0027] Figure 5 is a vibration diagram of the end platform of the multidimensional vibration platform of the four-sandwich piezoelectric actuator with coplanar arrangement around the four sides as described in Embodiment 2, rotating around the Y-axis.

[0028] Figure 6 is a vibration diagram of the end platform of the multidimensional vibration platform of the four-sandwich piezoelectric actuator with coplanar arrangement around the four sides as described in Embodiment 2, rotating around the X-axis.

[0029] Figure 7 is a schematic diagram of the vibration of the end platform of the multidimensional vibration platform of the four-sandwich piezoelectric actuator with coplanar arrangement around it as described in Embodiment 2, as it translates along the X-axis.

[0030] Figure 8 is a schematic diagram of the vibration of the end platform of the multidimensional vibration platform of the four-sandwich piezoelectric actuator with coplanar arrangement around it, as described in Embodiment 2, as it translates along the Y-axis.

[0031] Figure 9 is a schematic diagram of the vibration of the end platform of the multidimensional vibration platform of the four-sandwich piezoelectric actuator with coplanar arrangement around it, as described in Embodiment 2, as it translates along the Z-axis.

[0032] The components include: end platform 1, flexible hinge 2, actuation unit 3, amplitude rod 3-1, piezoelectric actuator 3-2, end cap 3-3, and first bolt 3-4. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them.

[0034] Implementation Method 1: Referring to Figures 1 to 3, this implementation method proposes a four-sandwich piezoelectric actuator type multidimensional vibration platform with evenly distributed coplanar arrangement around its four sides. The vibration platform includes: an end platform 1, four flexible hinges 2, and four actuation units 3. The four actuation units 3 are evenly distributed around the outer edge of the end platform, arranged orthogonally and symmetrically at 90-degree intervals, and the vibration axes of each actuation unit 3 are located in the same horizontal plane, preferably parallel to the YZ plane, forming a completely flattened overall configuration. Each actuation unit 3 is a composite functional module, including at least an amplitude transformer 3-1, a piezoelectric actuator 3-2, an end cap 3-3, and a first bolt 3-4. The amplitude transformer 3-1 is a variable cross-section rod with parallel end faces, an internal threaded hole at the thicker end, and a flexible hinge connected to the thinner end. The piezoelectric actuator 3-2 has parallel end faces and an axial through hole. Both the amplitude transformer 3-1 and the piezoelectric actuator 3-2 are provided with brackets for installation and fixation in the circumference, so as to achieve efficient coupling of the overall constraint and vibration energy of the vibration platform.

[0035] The end cap 3-3 is provided with an axial through hole, and is axially pre-tightened with the piezoelectric actuator 3-2 and the amplitude transformer 3-1 by the first bolt 3-4, with the axes of the three being collinear; the first bolt 3-4 is screwed into the threaded hole at the coarse end of the amplitude transformer 3-1 to provide a stable pre-tightening force and ensure that the piezoelectric ceramic is always in a compressive stress state; one end of the flexible hinge 2 is connected to the outer edge area of ​​the end platform 1, and the other end is connected to the thin end of the amplitude transformer 3-1; the flexible hinge 2 is omnidirectional symmetrical or biaxial symmetrical, which can efficiently transmit multi-directional bending deformation while suppressing undesirable rigid body displacement.

[0036] The four actuation units 3 are fixed to the same reference plane by brackets, and the overall structure has the same height, realizing an ultra-thin and flat design, which is convenient for embedding into micro systems.

[0037] In this embodiment, the first bolt 3-4 passes through the through holes of the end cap 3-3 and the piezoelectric actuator 3-2 in sequence, and is screwed into the internal threaded hole at the larger end of the amplitude rod 3-1, thereby fastening the three together along their local axial direction and applying a stable initial preload force to the piezoelectric ceramic. This preload force can effectively prevent the piezoelectric actuator 3-2 from bearing tensile stress during high-frequency vibration, prevent performance degradation or structural damage caused by tensile failure, and significantly improve the service life and output stability of the device.

[0038] Four actuation units 3 are evenly distributed at 90-degree intervals around the geometric center of the end platform 1 on the same horizontal reference plane, forming a strictly orthogonal centrally symmetrical layout. The vibration axes of all actuation units are located in this horizontal plane, preferably parallel to the YZ plane, making the entire platform structure highly consistent and axially stack-free, achieving a truly ultra-thin and flat design. This configuration not only satisfies the triple symmetry about the three mutually orthogonal coordinate planes XY, YZ, and ZX, but also ensures that the inertial forces and torques in non-target directions are symmetrically canceled when any degree of freedom is excited, fundamentally suppressing parasitic modes and motion coupling, and significantly improving the independence and trajectory fidelity of the six-degree-of-freedom vibration output.

[0039] Thanks to its coplanar arrangement and high symmetry, this vibration platform can excite all six degrees of freedom—three translations and three rotations—primarily through bending vibration modes. The flexible hinge 2 employs a universal symmetric or biaxial symmetric structure to efficiently transmit the multi-directional bending deformation generated by the amplitude transformer 3-1, while simultaneously constraining undesired rigid body displacements. This bending-driven excitation mechanism, compared to traditional methods relying on high-frequency, small-displacement longitudinal vibration, offers advantages such as larger displacement amplitude, more suitable frequency, and clearer mode separation, making it particularly suitable for high-precision, multi-dimensional manipulation at the micro-nano scale.

[0040] With its compact structure and extremely low profile, it is easy to embed into microrobots, microfluidic chips, endoscopic instruments, or space-constrained opto-electromechanical systems. By selectively exciting the bending vibration groups around the Y1 axis, the bending vibration groups around the Z1 axis, and the optional longitudinal vibration groups in each actuation unit 3, and by adjusting the signal phase and frequency, arbitrary combinations of six-degree-of-freedom high-frequency micro-vibration outputs can be flexibly realized on a single hardware platform. In addition, the dynamic characteristics of the end platform 1, such as resonant frequency and amplitude gain, can be customized by adjusting the stiffness of the flexible hinge 2 without changing the platform shape or actuation unit layout, supporting rapid adaptation and optimization for different loads, frequency bands, or travel requirements.

[0041] The end platform 1 is a disc-shaped structure with biaxial symmetry and central symmetry. Its geometric configuration is triple orthogonally symmetric about the XY plane, YZ plane and ZX plane, and has a clear geometric center as the symmetry reference. Typical configurations include, but are not limited to: square, circle, regular octagon, cross or regular polygon with rounded corners, as long as they satisfy the mirror symmetry about the Y axis and Z axis, and the 180-degree rotational symmetry about the geometric center.

[0042] The geometric center serves as the positioning reference for the four actuation units 3, which are evenly distributed around the perimeter at 90-degree intervals in the horizontal plane. This ensures that the end platform 1 and the overall structure together satisfy triple orthogonal symmetry about the XY, YZ, and ZX planes. This high-order symmetric configuration not only ensures that inertial forces and moments in non-target directions are symmetrically canceled out during excitation of any degree of freedom, fundamentally suppressing cross-coupling and parasitic modes, but also provides a structural basis for independently exciting all six degrees of freedom using only bending vibration modes. Under this symmetric constraint, the platform maintains excellent motion purity and dynamic stability during high-frequency micro-vibration, significantly improving the accuracy and repeatability of multidimensional micro-manipulation.

[0043] The piezoelectric actuator 3-2 includes a longitudinal vibration ceramic group and two mutually orthogonal bending vibration ceramic groups, which are used to excite any combination of bending vibrations around their local coordinate system Y1 axis and Z1 axis. Each ceramic group is provided with a driving electrode and a ground electrode, supporting multi-mode excitation or cooperative excitation. The longitudinal vibration ceramic group is an optional configuration and is activated when higher stiffness or higher frequency response X / Y translation is required. Otherwise, it can be omitted to simplify the structure and reduce costs.

[0044] In this embodiment, the piezoelectric actuator 3-2 integrates two mutually orthogonal bending vibration ceramic groups to excite bending vibrations about their local coordinate systems Y1 and Z1 axes, respectively, and optionally includes a longitudinal vibration ceramic group. This multimodal integrated design allows a single actuator unit to respond to multiple vibration modes, supporting flexible phase modulation and mode combination. All six degrees of freedom are based on bending vibration modes as the main excitation path. The longitudinal vibration ceramic group is only used as an auxiliary excitation means for Y-axis or Z-axis translation when a higher frequency response or enhanced stiffness is required, thus ensuring performance while also simplifying the structure and controlling costs.

[0045] Four actuation units 3 are evenly distributed at 90-degree intervals around the geometric center of the end platform 1 on the same horizontal plane. Their vibration axes are preferably coplanar and parallel to the YZ plane, giving the entire platform triple symmetry about the three mutually orthogonal coordinate planes XY, YZ, and ZX. In this highly symmetric configuration, by applying excitation signals with specific phase relationships to the bending ceramic groups in each actuation unit—whether in phase, out of phase, or differential—pure translational or rotational motion in the target direction can be accurately synthesized, effectively suppressing unwanted coupling components. This mechanism not only avoids the problem of cross-interference between longitudinal and bending vibration modes in traditional schemes but also significantly improves the trajectory fidelity and control accuracy of multi-degree-of-freedom vibrations. It is particularly suitable for applications with stringent requirements for motion decoupling and frequency response characteristics, such as ultrasound-assisted micromachining, non-destructive cell manipulation, and high-dynamic microrobots.

[0046] The vibration platform is symmetrical about the three orthogonal planes XY, YZ, and ZX.

[0047] The symmetrical structure of the vibration platform about the orthogonal plane allows the excitation of any degree of freedom to be symmetrically canceled out by non-target components, fundamentally suppressing cross-coupling and parasitic modes.

[0048] The piezoelectric actuator 3-2 can adopt any of the following structural forms: stacked, surface mount, or piezoelectric tube, or any combination thereof, to flexibly match different displacement stroke, frequency response characteristics, and load capacity requirements.

[0049] The vibration platform is symmetrical about three mutually orthogonal coordinate planes: XY, YZ, and ZX. This triple symmetry ensures that under any degree of freedom excitation, the inertial forces and torques in non-target directions are symmetrically canceled out, thereby fundamentally suppressing cross-coupling and parasitic modes, and providing structural protection for six-degree-of-freedom independent control based on bending vibration modes.

[0050] Under this coplanar flattened architecture, the structure of the piezoelectric actuator 3-2 can be flexibly selected according to actual needs: stacked piezoelectric actuators can provide high preload stiffness and stable bending vibration output, and are suitable for scenarios that require maintaining large-stroke bending deformation at high frequencies, such as ultrasonic-assisted micro-milling or high-dynamic micro-assembly; patch piezoelectric elements are easy to attach to the sidewall of the amplitude transformer, are thin and lightweight, and are particularly suitable for applications that are sensitive to the platform profile height and overall weight, such as micro-robot end effectors or embedded micro-manipulation modules; due to its circumferential symmetry, the piezoelectric tube structure can simultaneously excite bending vibration modes Y1 and Z1 around two orthogonal axes in a single unit, which is naturally adapted to the dual bending vibration excitation requirements of this invention, which is conducive to simplifying electrode wiring and improving modal consistency, and is suitable for precision systems with high integration and multi-degree-of-freedom collaborative control.

[0051] Regardless of the form used, each piezoelectric actuator is constrained within the same horizontal reference plane. Its excitation direction works in conjunction with the symmetrical layout of the platform to ensure that bending vibration energy is efficiently coupled to the end platform, achieving low coupling and high precision six-dimensional micro-vibration output.

[0052] The connection between the flexible hinge 2 and the end platform 1 and the amplitude rod 3-1 can be achieved by thread fastening, gluing, welding or integral molding, taking into account both ease of assembly and overall structural rigidity.

[0053] In the flattened configuration of this invention, the flexible hinge 2, as a key force-transmitting element connecting the end platform 1 and the amplitude transformer 3-1, needs to efficiently transmit multi-directional bending deformation under high-frequency bending vibration excitation while suppressing undesirable rigid body displacement. The integrity of its connection interface directly determines the transmission efficiency of vibration energy and the fidelity of modal response. Threaded fastening facilitates disassembly and parameter adjustment; adhesive bonding provides a continuous and uniform stress transition, reducing local stress concentration; welding or integral molding maximizes the overall structural integrity and avoids fretting wear and energy leakage under high-frequency alternating loads. Appropriate matching of connection processes for different application scenarios can effectively maintain the dynamic stability and long-term operational reliability of the system in the ultrasonic frequency band while ensuring flexible functionality.

[0054] The vibration platform can be externally installed and fixed via the amplitude rod 3-1 bracket, the piezoelectric actuator 3-2 bracket, or a combination of both. This ensures stable support of the system while effectively suppressing the leakage of vibration energy to the base and improving energy utilization efficiency.

[0055] In this embodiment, the supports for the amplitude transformer 3-1 and / or the piezoelectric actuator 3-2 are arranged on the same horizontal mounting reference plane, and preferably located near the displacement nodes of the platform's main bending vibration modes. This coplanar fixing strategy is not only highly compatible with the overall flattened configuration, but also provides stable external constraints while avoiding disruption of the system's symmetry about the three orthogonal planes XY, YZ, and ZX. By symmetrically distributing the support points in the low-sensitivity region of the vibration energy flow, the leakage path of high-frequency bending vibration to the base is effectively blocked. This improves the efficiency of electromechanical energy utilization while maintaining the purity and response consistency of the excitation modes of each degree of freedom, ensuring high fidelity of the six-dimensional micro-vibration output.

[0056] Implementation Method 2: This implementation method proposes an excitation method for a four-sandwich piezoelectric actuator with a coplanar arrangement around its four sides, forming a multidimensional vibration platform. The rotational vibration of the end platform 1 around the Z-axis is excited by applying an anti-phase signal to the local bending ceramic groups of the two pairs of diagonally opposite actuator units 3 (axis parallel to the Y-axis) around the Y-axis, with the frequency matching the bending resonance mode. The rotational vibration of the end platform 1 around the Y-axis is also excited by applying an anti-phase signal to the local bending ceramic groups of the two pairs of diagonally opposite actuator units 3 (axis parallel to the Z-axis) around the Y-axis, with the frequency matching the bending resonance mode. The rotational vibration of the end platform 1 around the X-axis is excited by applying the same signal to the local bending ceramic groups of all actuator units 3 around the Z-axis, with the frequency matching the bending resonance mode. The translational vibration of the end platform 1 along the X-axis is excited by applying the same signal to the local bending ceramic groups of all actuator units 3 around the Y-axis, with the frequency matching the bending resonance mode. Excitation during bending resonance mode; Translational vibration along the Y-axis of the end platform 1: There are two excitation methods under this degree of freedom. The first is to apply a reverse signal to the local bending vibration ceramic groups of the two pairs of diagonal axes parallel to the Z-axis around the Z1 axis, and the frequency matches the bending resonance mode. The second is to apply a reverse signal to the local longitudinal vibration ceramic groups of the two pairs of diagonal axes parallel to the Y-axis, and the frequency matches the longitudinal vibration resonance mode. Translational vibration along the Z-axis of the end platform 1: There are two excitation methods under this degree of freedom. The first is to apply a reverse signal to the local bending vibration ceramic groups of the two pairs of diagonal axes parallel to the Y-axis around the Z1 axis, and the frequency matches the bending resonance mode. The second is to apply a reverse signal to the local longitudinal vibration ceramic groups of the two pairs of diagonal axes parallel to the Z-axis, and the frequency matches the longitudinal vibration resonance mode.

[0057] The excitation method uses a piezoelectric actuator 3-2 as the execution unit. Relying on a symmetrical configuration where four actuator units 3 are evenly distributed around the horizontal plane and their vibration axes are coplanar, pure six-degree-of-freedom micro-vibrations are synthesized on the end platform 1 by precisely controlling the phase and frequency of the bending ceramic groups in each actuator unit 3. This method eliminates the dependence on longitudinal vibration modes, mainly utilizing bending vibrations around the local Y1 and Z1 axes, combined with a triple orthogonal symmetrical layout, to achieve efficient decoupling between the degrees of freedom. Since the entire system has no sliding pairs or rotary joints, and all deformations are elastically transmitted through flexible hinges 2, it possesses high dynamic response, low thermal drift, and long-term operational stability at the micrometer to submicrometer scale. It is particularly suitable for cutting-edge applications such as ultrasound-assisted micromachining, cell-level biological manipulation, micro-optical-mechanical platform stabilization, and multidimensional active vibration suppression in space-constrained environments.

[0058] Example 1: A multidimensional vibration platform with four sandwich-type piezoelectric actuators evenly distributed and coplanarly arranged, mainly comprising: an end platform 1, four flexible hinges 2, and four actuation units 3; the four actuation units 3 are evenly distributed around the outer edge of the end platform, arranged orthogonally and symmetrically at 90-degree intervals, and the vibration axes of each actuation unit 3 are located in the same horizontal plane, preferably parallel to the YZ plane, forming a completely flattened overall configuration; each actuation unit 3 is a composite functional module, including at least an amplitude transformer 3-1, a piezoelectric actuator 3-2, an end cap 3-3, and a first bolt 3-4; the amplitude transformer 3-1 is a variable cross-section rod with parallel end faces, an internal threaded hole at the thicker end, and a flexible hinge connected to the thinner end; the piezoelectric actuator 3-2 has parallel end faces and an axial through hole; both the amplitude transformer 3-1 and the piezoelectric actuator 3-2 are provided with brackets for installation and fixation in the circumference, so as to achieve efficient coupling of the overall constraint and vibration energy of the vibration platform.

[0059] The end cap 3-3 has an axial through hole, and is axially pre-tightened with the piezoelectric actuator 3-2 and the amplitude transformer 3-1 by the first bolt 3-4, with the axes of the three being collinear; the first bolt 3-4 is screwed into the threaded hole at the coarse end of the amplitude transformer 3-1 to provide a stable pre-tightening force, ensuring that the piezoelectric ceramic is always under compressive stress; the upper end of the flexible hinge 2 is fixedly connected to the lower surface of the end platform 1, and the lower end is connected to the thin end of the amplitude transformer 3-1; the flexible hinge 2 is omnidirectional symmetrical or biaxial symmetrical, which can efficiently transmit multi-directional bending deformation while suppressing undesirable rigid body displacement; the four actuation units 3 are fixed to the same reference plane by brackets, with a consistent overall structural height, realizing an ultra-thin and flat design, which is convenient for embedding into micro systems.

[0060] The end platform 1 is a circular disk structure with a geometric configuration that is triple orthogonally symmetrical about the XY plane, YZ plane and ZX plane, and has a clear geometric center as a symmetry reference.

[0061] The piezoelectric actuator 3-2 includes a longitudinal vibration ceramic group and two mutually orthogonal bending vibration ceramic groups for exciting bending vibrations around their local coordinate system Y1 axis and Z1 axis, respectively. Each ceramic group is provided with a driving electrode and a ground electrode, supporting multi-mode excitation or synergistic excitation. The longitudinal vibration ceramic group is an optional configuration and is activated when higher stiffness or higher frequency response X / Y translation is required. Otherwise, it can be omitted to simplify the structure and reduce costs.

[0062] The vibration platform is symmetrical about the three orthogonal planes XY, YZ, and ZX.

[0063] The piezoelectric actuator 3-2 can be in a stacked structure or any combination thereof, to flexibly match different displacement stroke, frequency response characteristics and load capacity requirements.

[0064] The connection between the flexible hinge 2 and the end platform 1 and the amplitude rod 3-1 can be made in one piece, taking into account both ease of assembly and overall structural rigidity.

[0065] The vibration platform can be externally installed and fixed through the piezoelectric actuator 3-2 bracket, which effectively suppresses the leakage of vibration energy to the base while ensuring stable support of the system and improving energy utilization efficiency.

[0066] Referring to Figure 4, the rotational vibration of the end platform 1 around the Z-axis is excited by applying an anti-phase signal to the local bending vibration ceramic groups of the two pairs of diagonally opposite actuator units 3 with axes parallel to the Y-axis around the Y-axis, and the frequency matches the bending resonance mode; Referring to Figure 5, the rotational vibration of the end platform 1 around the Y-axis is excited by applying an anti-phase signal to the local bending vibration ceramic groups of the two pairs of diagonally opposite actuator units 3 with axes parallel to the Z-axis around the Y-axis, and the frequency matches the bending resonance mode; Referring to Figure 6, the rotational vibration of the end platform 1 around the X-axis is excited by applying the same signal to the local bending vibration ceramic groups of all actuator units 3 around the Z-axis, and the frequency matches the bending resonance mode; Referring to Figure 7, the translational vibration of the end platform 1 along the X-axis is excited by applying the same signal to the local bending vibration ceramic groups of all actuator units 3 around the Y-axis, and the frequency matches the bending resonance mode; Referring to Figure 8, the end platform... Translational vibration along the Y-axis of platform 1: There are two excitation methods for this degree of freedom. The first is to apply a reverse signal to the local bending ceramic groups of the two pairs of diagonal axes parallel to the Z-axis around the Z1 axis, and the frequency matches the bending resonance mode. The second is to apply a reverse signal to the local longitudinal vibration ceramic groups of the two pairs of diagonal axes parallel to the Y-axis, and the frequency matches the longitudinal resonance mode. Referring to Figure 9, translational vibration along the Z-axis of end platform 1: There are two excitation methods for this degree of freedom. The first is to apply a reverse signal to the local bending ceramic groups of the two pairs of diagonal axes parallel to the Y-axis around the Z1 axis, and the frequency matches the bending resonance mode. The second is to apply a reverse signal to the local longitudinal vibration ceramic groups of the two pairs of diagonal axes parallel to the Z-axis, and the frequency matches the longitudinal resonance mode.

[0067] The vibration platform of this invention relies on a coplanar configuration of four actuator units 3 evenly distributed at 90-degree intervals around the horizontal reference plane. Combined with the triple symmetry of the end platform 1 about the three mutually orthogonal coordinate planes XY, YZ, and ZX, high-frequency microscale vibration output with six degrees of freedom can be achieved through bending vibration modes, including translation along the X, Y, and Z axes and rotation around the X, Y, and Z axes. This high-order symmetric layout ensures that the inertial components in the undesired direction are symmetrically canceled when any target mode is excited, significantly suppressing motion coupling and parasitic response. Thus, high modal purity and strong decoupling performance are achieved in a single compact structure, making it suitable for cutting-edge applications such as multidimensional micro-assembly, non-destructive cell manipulation, omnidirectional drive of microrobots, ultrasound-assisted precision machining, and six-degree-of-freedom active vibration isolation in space-constrained environments.

[0068] Those skilled in the art will understand that the above description is merely a preferred embodiment of the present invention, and the features described in the various embodiments and / or claims of this disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly described in this disclosure. This is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0069] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if these modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include these modifications and modifications.

Claims

1. A multidimensional vibration platform with four-sandwich piezoelectric actuators evenly distributed and coplanarly arranged around its four sides, characterized in that, The vibration platform includes an end platform (1), four flexible hinges (2), and four actuation units (3). The four actuation units (3) are evenly distributed around the outer edge of the end platform (1), arranged in a 90-degree equally spaced orthogonal symmetrical pattern, and the vibration axes of each actuation unit (3) are located in the same horizontal plane, forming a completely flattened overall configuration. Each actuation unit (3) includes at least an amplitude transformer (3-1), a piezoelectric actuator (3-2), an end cap (3-3), and a first bolt (3-4). The amplitude transformer (3-1) is a variable cross-section rod with parallel end faces, an internal threaded hole at the thick end, and a flexible hinge connected to the thin end. The piezoelectric actuator (3-2) has parallel end faces and a through hole in the axial direction. Both the amplitude transformer (3-1) and the piezoelectric actuator (3-2) are circumferentially provided with mounting and fixing mechanisms. The bracket is used to achieve the overall constraint of the vibration platform and the efficient coupling of vibration energy. The end cap (3-3) is provided with an axial through hole, and is axially pre-tightened with the piezoelectric actuator (3-2) and the amplitude rod (3-1) by the first bolt (3-4). The axes of the three are collinear. The first bolt (3-4) is screwed into the threaded hole at the coarse end of the amplitude rod (3-1) to provide a stable pre-tightening force and ensure that the piezoelectric ceramic is always in a compressive stress state. One end of the flexible hinge (2) is connected to the outer edge area of ​​the end platform (1), and the other end is connected to the thin end of the amplitude rod (3-1). The flexible hinge (2) is omnidirectional symmetrical or biaxial symmetrical and is used to transmit multi-directional bending deformation while suppressing undesirable rigid body displacement. The four actuation units (3) are fixed to the same reference plane and have the same height by the bracket to achieve an ultra-thin and flat design.

2. The four-sandwich piezoelectric actuator type multidimensional vibration platform with uniformly distributed coplanar arrangement on all four sides according to claim 1, characterized in that, The end platform (1) is a disk-shaped structure with dual-axis symmetry and central symmetry, that is, the XY plane, YZ plane and ZX plane are triple orthogonally symmetric.

3. The four-sandwich piezoelectric actuator type multidimensional vibration platform with uniformly distributed coplanar arrangement on all four sides according to claim 1, characterized in that, The shape of the end platform (1) is any one of a square, a circle, a regular octagon, a cross, or a regular polygon with rounded corners.

4. A four-sandwich piezoelectric actuator with a coplanar arrangement on all four sides, as described in claim 1, is characterized in that... The piezoelectric actuator (3-2) includes any combination of longitudinal vibration ceramic group and two mutually orthogonal bending vibration ceramic groups. Each ceramic group is provided with a driving electrode and a grounding electrode, supporting multimodal excitation or cooperative excitation.

5. A four-sandwich piezoelectric actuator with a coplanar arrangement on all four sides, as described in claim 4, is characterized in that... The two mutually orthogonal bending ceramic groups are used to excite bending vibrations about their local coordinate systems Y1 and Z1 axes, respectively.

6. A four-sandwich piezoelectric actuator with a coplanar arrangement around its four sides, as described in claim 4, is characterized in that... The longitudinal vibration ceramic assembly is an optional configuration and is activated when high stiffness or high frequency response is required for X / Y direction translation.

7. A four-sandwich piezoelectric actuator with a coplanar arrangement on all four sides, as described in claim 1, is characterized in that... The piezoelectric actuator (3-2) can be any of the following structural forms: stacked, surface mount, piezoelectric tube, or any combination thereof, to match different displacement stroke, frequency response characteristics, and load capacity requirements.

8. A four-sandwich piezoelectric actuator with a coplanar arrangement on all four sides, as described in claim 1, is characterized in that... The connection between the flexible hinge (2) and the end platform (1) and the amplitude rod (3-1) is achieved by thread fastening, gluing, welding or integral molding process.

9. A four-sandwich piezoelectric actuator with a coplanar arrangement on all four sides, as described in claim 1, is characterized in that... The vibration platform is externally installed and fixed via an amplitude transformer bracket, a piezoelectric actuator bracket, or a combination of both.

10. An excitation method for a multidimensional vibration platform with four-sandwich piezoelectric actuators arranged coplanarly around its four sides, characterized in that... The method is based on a four-sandwich piezoelectric actuator with a coplanar arrangement around its four sides, as described in claim 1, and includes: rotational vibration of the end platform (1) around the Z-axis: excited by applying an anti-phase signal to the local bending ceramic groups of the two pairs of diagonal actuators (3) with axes parallel to the Y-axis around the Y-axis, and the frequency matching the bending resonance mode; rotational vibration of the end platform (1) around the Y-axis: excited by applying an anti-phase signal to the local bending ceramic groups of the two pairs of diagonal actuators (3) with axes parallel to the Z-axis around the Y-axis, and the frequency matching the bending resonance mode; rotational vibration of the end platform (1) around the X-axis: excited by applying the same signal to the local bending ceramic groups of all actuators (3) around the Z-axis, and the frequency matching the bending resonance mode; translational vibration of the end platform (1) along the X-axis: excited by applying the same signal to the local bending ceramic groups of all actuators (3) around the Z-axis, and the frequency matching the bending resonance mode; translational vibration of the end platform (1) along the X-axis: local vibration of all actuators (3) around the Z-axis around the X-axis. The end platform (1) is excited when the same signal is applied to the bending ceramic group around the Y1 axis and the frequency matches the bending resonance mode; the translational vibration along the Y axis of the end platform (1) includes the excitation when the reverse signal is applied to the local bending ceramic group around the Z1 axis of the two pairs of diagonal actuators (3) whose axes are parallel to the Z axis and the frequency matches the bending resonance mode; and the excitation when the reverse signal is applied to the local longitudinal vibration ceramic group of the two pairs of diagonal actuators (3) whose axes are parallel to the Y axis and the frequency matches the longitudinal vibration resonance mode; the translational vibration along the Z axis of the end platform (1) includes the excitation when the reverse signal is applied to the local bending ceramic group around the Z1 axis of the two pairs of diagonal actuators (3) whose axes are parallel to the Y axis and the frequency matches the bending resonance mode; and the excitation when the reverse signal is applied to the local longitudinal vibration ceramic group of the two pairs of diagonal actuators (3) whose axes are parallel to the Z axis and the frequency matches the longitudinal vibration resonance mode.

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