A transfer stamp with an integrated sensing and driving system and a transfer method thereof

Abstract

This invention discloses a transfer stamp with controllable adhesion and multi-dimensional force sensing. The stamp integrates a driving sensing system within its cylindrical unit. This system has a stool-shaped frame, which is inverted. A driving module for inducing active deformation of the system is located on the outer side of any one "leg" of the stool-shaped frame, and a sensing module for receiving force changes is located on the outer side of each of the remaining "legs." Both the sensing module and the driving module have electrodes positioned at their respective feet. The adhesion force is adjusted by changing the stamp's bending amplitude through regulating the electrical excitation parameters of the driving module. This invention also discloses a method for transfer printing using the aforementioned stamp. This invention features "active bending" and "multi-dimensional force sensing" functions, enabling adjustment of the adhesion force between the stamp and the interface of micro / nano devices, thereby switching between the pickup and release states of the micro / nano devices; it can also instantly determine the pickup and release states of the micro / nano devices.

Description

Technical Field

[0001] This invention belongs to the field of micro-nano manufacturing, specifically relating to a transfer stamp that integrates controllable adhesion force and a multi-dimensional force sensing drive system. Background Technology

[0002] As the manufacturing of materials, structures, devices, and systems tends towards miniaturization, intelligence, diversification, and extreme limits, micro-nano manufacturing technology has become a hot topic in global manufacturing technology competition and a strategically vital frontier technology for the 21st century. Currently, micro-nano manufacturing technologies mainly include photolithography, electron beam engraving, atomic layer deposition, and nanoimprint lithography, but they still face challenges such as fundamental physical and material limitations, imbalances in design and process coordination, high cost and complexity, and low processing efficiency. Transfer printing technology, as an advanced micro-nano manufacturing process, can overcome the limitations of material and process compatibility, picking up a large number of micro-devices in parallel from a donor substrate and transferring them at extremely high speeds to rapidly and accurately fabricate stretchable and flexible inorganic electronic devices. Transfer printing technology is mainly achieved through polymer stamps, and its process can be divided into two stages: the picking stage, which uses a stamp to peel the functional device from its donor substrate; and the printing stage, which uses a stamp to imprint the functional device onto the acceptor substrate. Transfer printing is essentially a competitive process of interfacial adhesion. Ideally, the stamp's adhesion should be stronger during the pickup stage and weaker than the adhesion between the device and the substrate during the printing stage. However, current transfer printing technologies often focus too much on the positioning and alignment accuracy of the transfer process, neglecting the dynamic control of interfacial adhesion; they also struggle to simultaneously decouple and measure the tangential and normal forces acting on the stamp during the transfer process, lacking multidimensional force sensing capabilities. Separating the "sensing" and "execution" functions prevents the stamp from adaptively adjusting adhesion based on real-time mechanical feedback. Therefore, research is needed on the design of transfer stamps with high-performance integrated drive sensing systems to develop a transfer stamp that integrates controllable adhesion and a multidimensional force sensing drive sensing system. Summary of the Invention

[0003] This invention provides a transfer stamp that integrates controllable adhesion force and a multi-dimensional force sensing drive system to solve the technical problems existing in the prior art.

[0004] The present invention provides a technical solution to address the technical problems existing in the prior art: a transfer stamp with controllable adhesion and multi-dimensional force sensing functions. The main body of the stamp is made of a viscoelastic material and includes a substrate and multiple identical stamp units. These stamp units are arranged in a rectangular array below the substrate. Each stamp unit has a column connected to the substrate. A driving sensing system is integrated within the column. The driving sensing system has a stool-shaped frame, which is inverted and coaxial with the column. The "stool surface" portion of the stool-shaped frame is encapsulated and fixed to the bottom of the column. The "stool leg" section extends vertically upwards and passes through the bottom of the column. The end of the "stool leg" section of the stool-shaped frame is provided with a foot extending radially outwards. The foot is encapsulated and fixed inside the bottom surface of the base. A drive module for causing the system to generate active deformation is provided on the outside of any "stool leg" section of the stool-shaped frame. A sensing module for receiving force changes is provided on the outside of each of the remaining "stool legs" sections. The sensing module and the drive module are each provided with an electrode. The electrode is located on the corresponding foot. The adhesion force is adjusted by changing the bending amplitude of the stamp by adjusting the electrical excitation parameters of the drive module.

[0005] Based on the above solution, the present invention has made the following improvements:

[0006] The stool-shaped frame is made of viscoelastic material and is fabricated based on a micro-origination process.

[0007] The sensing module is made of any one of piezoelectric, piezoresistive, or capacitive materials.

[0008] The drive module is made of piezoelectric materials or shape memory alloy materials.

[0009] Another technical solution adopted by the present invention to solve the technical problems existing in the prior art is: a method for transfer printing using the above-mentioned stamp, wherein: in the extraction stage: firstly, the mechanical system confirms that the stamp has successfully contacted the micro-nano device based on the normal force signal detected by the sensing module, then applies pre-pressure, and then moves upward; in the printing stage: firstly, the mechanical system confirms that the micro-nano device has successfully contacted the target substrate based on the normal force signal detected by the sensing module, then the stamp is placed still. During the stilling process, the stamp is bent and deformed by adjusting the electrical excitation parameters of the driving module. After deformation, the stamp is confirmed to have detached from the adhesive state based on the fact that the sensing module can no longer detect the normal force signal, and the printing is completed.

[0010] The advantages and positive effects of this invention are as follows: The driving sensing system, by employing a stool-shaped frame and a driving module, enables the stamp to have an "active bending" function, allowing adjustment of the adhesion force between the stamp and the micro / nano device interface. This enables rapid switching between stamp pickup and printing functions, resulting in high yield, high reliability, and high repeatability. Furthermore, the driving sensing system, by employing a stool-shaped frame and a sensing module, enables the stamp to have a "multi-dimensional force sensing" function, achieving precise and real-time sensing of the contact state between the stamp and the recipient substrate. This allows for immediate judgment of the pickup and release status of the micro-device, significantly improving transfer yield and process reliability. In summary, this invention, by integrating a driving sensing system with a driving module and a sensing module into the transfer stamp, endows the stamp with controllable adhesion force and multi-dimensional force detection capabilities. This transforms a process that previously relied on experience into a quantifiable and repeatable precision manufacturing process. During manufacturing, it can monitor the changes in multi-dimensional forces acting on the stamp in real time during the transfer process, altering the adhesion force between the stamp and the micro / nano device interface, thereby controllably achieving the extraction and release of micro / nano devices. Meanwhile, since the stamp is composed of multiple stamp units with the same structure arranged in a rectangular array, large-area precise transfer can be achieved by integrating a driving sensing system. Attached Figure Description

[0011] Figure 1 This is a two-dimensional structural diagram of the seal unit of the present invention;

[0012] Figure 2 This is a three-dimensional diagram of the driving sensing system of the present invention;

[0013] Figure 3 for Figure 2 Top view;

[0014] Figure 4 This is a schematic diagram illustrating the functional principle of the driving and sensing modules of the driving sensing system of the present invention. Figure 1 ;

[0015] Figure 5 This is a schematic diagram illustrating the functional principle of the driving and sensing modules of the driving sensing system of the present invention. Figure 2 ;

[0016] Figure 6 This is a schematic diagram of the release micro / nano device principle of the driving sensing system of the present invention;

[0017] Figure 7 This is a flowchart of the transfer operation used in this invention.

[0018] In the figure: 1-substrate; 2-pillar; 3-driving sensing system; 4-stool-shaped frame; 5-sensing module; 6-driving module; 7-power-on electrode; 8-micro-nano device. Detailed Implementation

[0019] To further understand the invention's content, features, and effects, the following embodiments are provided, and detailed descriptions are given below in conjunction with the accompanying drawings:

[0020] Please see Figures 1 to 7 A transfer stamp with controllable adhesion and multi-dimensional force sensing is disclosed. The main body of the stamp is made of viscoelastic material and includes a substrate 1 and multiple identical stamp units arranged in a rectangular array below the substrate 1. Each stamp unit has a column 2 connected to the substrate 1. A drive sensing system 3 is integrated within the column 2. The drive sensing system 3 has a stool-shaped frame 4, which is inverted and coaxial with the column 2. The "stool surface" of the stool-shaped frame 4 is encapsulated and fixed to the bottom of the column 2, and the "legs" extend vertically upwards. The bottom of the column 2 is penetrated through the stool-shaped frame 4. The end of the stool leg is provided with a foot that extends radially outward. The foot is encapsulated and fixed in the bottom surface of the base 1. A drive module 6 for causing the system to generate active deformation is provided on the outside of any one of the stool legs of the stool-shaped frame 4. Each of the remaining stool legs is provided with a sensing module 5 for receiving force changes. The sensing module 5 and the drive module 6 are each provided with an electrode 7. The electrode 7 is located in the corresponding foot. The bending amplitude of the stamp is changed by adjusting the electrical excitation parameters of the drive module 6, thereby adjusting the adhesion force.

[0021] The more preferred solution in this embodiment is as follows:

[0022] The stool-shaped frame 4 is made of viscoelastic material and is prepared based on micro-folding technology. Specifically, it is a three-dimensional structure formed by applying pre-strain to a two-dimensional micro-nano structure to induce nonlinear buckling deformation.

[0023] The sensing module 5 is made of any one of piezoelectric, piezoresistive, or capacitive materials.

[0024] The drive module 6 is made of piezoelectric materials or shape memory alloy materials.

[0025] The overall configuration of the aforementioned stool-shaped frame 4 includes, but is not limited to, three-legged, four-legged, and five-legged configurations. The stool-shaped frame 4 is made of viscoelastic materials, including but not limited to PDMS. Taking the four-legged stool-shaped frame 4 as an example, the stool surface is the core, and the four "stool legs" are distributed outward in a cross shape. The included angle between any two adjacent legs is 90°, forming a symmetrical spatial configuration. The structural parameters of the four "stool legs" are consistent. Sensing modules 5 for receiving force changes are respectively set at the same position on three of the legs, and a driving module 6 for causing the system to generate active deformation is set at the same position on the remaining leg. The materials of the sensing modules 5 include, but are not limited to, piezoelectric materials, piezoresistive materials, and capacitive materials, and the materials of the driving module 6 include, but are not limited to, piezoelectric materials and shape memory alloy materials. The system is equipped with power-on electrodes 7, which include two types: one is a driving electrode connected to the driving module 6, and the other is a sensing electrode connected to the sensing module 5. Through the above parts, a "one-drive, multi-sensor" topological architecture layout is formed in space.

[0026] The working principle of the above-mentioned driving sensing system:

[0027] Please see Figures 5-6 The active deformation and adhesion control of the stamp are achieved through a drive module. Under electrical excitation, the drive module outputs precise directional deformation. This deformation acts on the stool-shaped frame, creating an unbalanced torque that drives the stamp to undergo quantifiable bending deformation. When the stamp bends, tangential shear stress is generated at its contact interface with the micro / nano device 8, breaking the original force state dominated only by normal force: during the pickup phase, the stamp does not bend, and the interface crack is a single opening type (Type I), with high adhesion ensuring stable device adsorption; during the release phase, electrical excitation drives the stamp to bend, and the crack propagation mode changes to an opening-sliding coupling type (Type I-II), significantly reducing the critical dissociation force and consequently lowering the interface adhesion. When the adhesion force is lower than the interfacial bonding force between the device and the target substrate, the device can detach from the stamp surface and complete release. By adjusting the electrical excitation parameters to change the stamp bending amplitude, precise control of the adhesion force can be achieved. Please refer to [link to relevant documentation]. Figures 4-5 The "multi-dimensional force sensing" function of the driving sensing system is realized through the collaboration of three sensing modules. Each sensing module generates corresponding changes in electrical characteristics under the action of external force. By detecting the amount of change and combining the symmetrical distribution design of the three sensing modules, the driving sensing system can simultaneously detect the normal force and tangential force on the seal, thereby realizing all-round monitoring of the complex stress state of the seal.

[0028] The method of transferring the seal as described above:

[0029] Extraction Stage: The mechanical system first moves the stamp horizontally, while simultaneously judging based on real-time visual feedback from orthogonally arranged industrial cameras. If the stamp is not directly above the micro / nano device 8 on the source substrate, the horizontal position is adjusted until the camera confirms accurate stamp positioning. Subsequently, the mechanical system moves the stamp vertically downward. During this process, the relative position of the stamp and the micro / nano device 8 is determined by image detection from the industrial camera. The normal force signal detected by the sensing module confirms whether the stamp and the micro / nano device have made successful contact. After successful contact, the stamp applies pre-pressure to the micro / nano device 8, and the mechanical system moves the stamp vertically upward to extract the micro / nano device 8 from the source substrate.

[0030] Printing Stage: The mechanical system moves the stamp with the micro / nano devices 8 adsorbed on it horizontally. The position is determined by real-time visual feedback from an orthogonal industrial camera at the target location. If the stamp is not directly above the target location on the substrate, the horizontal position is adjusted until precise positioning is achieved. Then, the mechanical system moves the stamp vertically downwards. During this process, image detection from the industrial camera helps determine the relative position of the micro / nano devices 8 and the target substrate. The normal force signal detected by the sensor module confirms successful contact between the stamp and the micro / nano devices. After successful contact, the stamp is left to stand still. During this standing period, the electrical excitation parameters of the drive module are adjusted to cause the stamp to bend. Again, image detection from the industrial camera helps determine if bending deformation has occurred. Tangential shear stress detected by the sensor module confirms bending deformation. If the sensor module does not detect a normal force signal, the stamp has detached from its adhesive state. At this point, the mechanical system moves the stamp vertically upwards, completing the printing of the micro / nano devices 8. If further operation is needed, the mechanical system, with camera assistance, moves the stamp to the next batch of micro / nano devices 8, repeating the above extraction process until all micro / nano devices 8 have been printed.

[0031] The seal of the integrated driving sensing system includes, but is not limited to, a microstructure seal.

[0032] Although preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other modifications under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these modifications are within the scope of protection of the present invention.

Claims

1. A transfer stamp with controllable adhesion and multi-dimensional force sensing functions, wherein the main body of the stamp is made of viscoelastic material, and comprises a substrate and multiple stamp units with identical structures, the stamp units being arranged in a rectangular array below the substrate, each stamp unit having a column connected to the substrate, and a driving sensing system integrated within the column, characterized in that, The driving sensing system includes a stool-shaped frame, which is inverted and coaxial with the column. The "stool surface" of the stool-shaped frame is encapsulated and fixed to the bottom of the column, and the "stool legs" extend vertically upward and pass through the bottom of the column. The ends of the "stool legs" of the stool-shaped frame have radially outward-extending feet, which are encapsulated and fixed inside the bottom surface of the base. A driving module for generating active deformation of the system is provided on the outside of any one of the "stool legs" of the stool-shaped frame, and a sensing module for receiving force changes is provided on the outside of each of the remaining "stool legs". The sensing module and the driving module each have an electrode, which is located on the corresponding foot. The adhesion force is adjusted by changing the bending amplitude of the stamp by adjusting the electrical excitation parameters of the driving module.

2. The transfer stamp with controllable adhesion and multi-dimensional force sensing function according to claim 1, characterized in that, The stool-shaped frame is made of viscoelastic material and is fabricated based on a micro-origination process.

3. The transfer stamp with controllable adhesion and multi-dimensional force sensing function according to claim 1, characterized in that, The sensing module is made of any one of piezoelectric, piezoresistive, and capacitive materials.

4. The transfer stamp with controllable adhesion and multi-dimensional force sensing function according to claim 1, characterized in that, The drive module is made of piezoelectric materials or shape memory alloy materials.

5. A method for transfer printing using a seal as described in any one of claims 1 to 4, characterized in that, Extraction stage: First, the mechanical system confirms that the stamp has successfully contacted the micro / nano device based on the normal force signal detected by the sensing module. Then, a pre-pressure is applied, and then the stamp is moved upward. Printing stage: First, the mechanical system confirms that the micro-nano device has successfully contacted the target substrate based on the normal force signal detected by the sensing module. Then, the stamp is left to stand still. During the standing process, the stamp is bent and deformed by adjusting the electrical excitation parameters of the driving module. After deformation, the normal force signal is no longer detected by the sensing module, confirming that the stamp has detached from the adhesive state, and the printing is completed.

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