Optothermoelectric tweezers device for dry interface and method for manipulating micro-nano objects thereof

Abstract

The present application relates to a kind of photothermal impact tweezers device for dry interface and its control method to micro-nano object, utilize the photothermal effect of micro-nano object itself, under the excitation of pulsed laser, convert light energy into heat energy, make its internal rapid thermal expansion, transient thermal expansion generates rapid impact load in object interior, in the duration of pulse, photothermal impact continuously act on micro-nano object, deposit enough energy in micro-nano object interior to generate great force or acceleration.Combining photothermal impact and interface friction, micro-nano object can directly overcome the resistance of dry interface and be captured by the light trap formed at the center of light spot.By changing the position of light spot or substrate, further control the movement of micro-nano object.The present application has the advantages of low excitation power, high control precision, fast response speed and no thermal damage.The stable capture characteristics of the present application completely control the movement of micro-nano object by light spot movement, realize the free movement of micro-nano object on two-dimensional dry interface.

Description

Technical Field

[0001] This invention relates to a motion control technology for micro- and nano-objects, and more particularly to a photothermal tweezers device for a drying interface and a method for manipulating micro- and nano-objects thereon. Background Technology

[0002] With the rapid development of science and technology, various research fields, such as chip integration, surface engineering, biomedicine, and microelectronics, have entered the stage of miniaturization. Researchers are seeking more miniaturized and lightweight alternatives, and thus the demand for efficient manipulation of micro and nano objects on solid triboelectric interfaces has also emerged. Among them, traditional optical tweezers, dielectrophoresis, and acoustic eddy currents are known powerful tools for manipulating micro and nano objects.

[0003] Dry solid interfaces pose a significant obstacle to the movement of micro- and nano-sized objects, with their normal adhesion and tangential frictional forces reaching micro Newtons (10⁻⁶). -6 The order of magnitude is N, while the traditional optical tweezers technique, which utilizes the mechanical effects of momentum transfer during the interaction of light and particles, can only generate Flying Newtons (10 N). -15 N) to leather (10) -12 Light force on the order of nanoseconds (N) is insufficient to overcome the aforementioned resistance, making it difficult to drive and control micro / nano objects in direct contact with solid interfaces. Therefore, related research is often limited to micro / nano objects suspended in fluid media. The non-negligible Brownian motion in fluid media severely limits the capture stability, manipulation precision, driving distance, and control duration of such techniques. Furthermore, traditional optical tweezers and related techniques often require the use of objectives with extremely high numerical apertures to focus the light spot, creating a very strong light field at the objective focal point to capture and manipulate micro / nano objects. This highly focused, high-power light spot inevitably causes the micro / nano object to absorb a large amount of laser energy while being manipulated, resulting in thermal damage. Additionally, prolonged operation in liquid environments inevitably leads to contamination of the manipulation equipment or the micro / nano object.

[0004] To drive micro- and nano-sized objects at solid interfaces, additional conditions or special environments are usually required. For example, using curved optical fiber structures to reduce the contact area, or coating the surface with a phase change material to achieve surface lubrication, can reduce interfacial friction. This allows laser manipulation techniques, such as photo-ultrasound based on the photo-thermal-elastic wave principle and photo-induced phase change technology based on the photo-thermal-deformation principle, to be applied to drive micro- and nano-sized objects at solid interfaces. However, these methods lack the optical trap-like phenomenon found in traditional optical tweezers, thus failing to achieve stable capture of micro- and nano-sized objects, let alone precise control over their motion.

[0005] Therefore, there is an urgent need to study a device that can directly overcome frictional forces on dry solid interfaces to drive, capture, and manipulate micro and nano objects to promote the development of related scientific fields. Summary of the Invention

[0006] To address the limitations of traditional optical tweezers technology, such as low output force, low manipulation precision, and poor controllability, which prevent direct driving, capture, and control of micro / nano objects at dry solid interfaces, this invention proposes a photothermal impact tweezers device for dry interfaces and its method for manipulating micro / nano objects. Utilizing the photothermal effect of the micro / nano object itself, under pulsed laser excitation, light energy is converted into heat energy, causing rapid thermal expansion within the object. This transient thermal expansion generates a rapid impact load on the object's interior, known as photothermal impact. During the pulse duration, the photothermal impact continuously acts on the micro / nano object, depositing sufficient energy within it to generate significant force or acceleration. Combining the photothermal impact with interfacial friction, the micro / nano object can directly overcome the resistance of the dry interface and be driven, then captured by a light trap-like structure formed at the center of the laser spot. Further control of the micro / nano object's motion can be achieved by changing the position of the laser spot or the substrate. This invention offers advantages such as low excitation power, high control precision, fast response speed, and no thermal damage. It enables multi-dimensional manipulation of micro / nano objects at solid interfaces, is highly compatible with existing optical tweezers equipment, and has a wide range of applications.

[0007] The technical solution of the present invention is: a photothermal tweezers device for a dry interface, used to drive, capture and control the motion of micro-nano objects at a dry solid interface, the device including a laser driving module, an observation and capture module and a motion control module;

[0008] The laser driving module is used to generate pulse output signals with adjustable frequency, variable power, and switchable wavelength;

[0009] The observation and capture module is used for real-time observation and capture of micro- and nano-sized objects;

[0010] The motion control module is used to control the positional relationship between the micro / nano object placed on the dry solid interface and the capture spot generated by the observation and capture module.

[0011] Preferably, the laser driving module includes a signal generator, a laser, and an optical power control module arranged in sequence; the signal generator is connected to the laser and is used to generate pulse output signals of different frequencies; the optical power control module is on the same optical axis as the laser, receives the optical pulses output by the laser, and adjusts the power of the optical pulse signals.

[0012] Preferably, the laser is a nanosecond laser, but it is not limited to this. Picosecond lasers, femtosecond lasers, or even modulated long-pulse lasers can all meet the driving conditions with a pulse width in the range of 50 fs to 100 μs.

[0013] Preferably, the wavelength of the laser is 532nm, but it is not limited to this. The laser wavelength is the absorption wavelength of the manipulated micro-nano object, that is, the driving conditions are met in the range of 300nm-2μm.

[0014] Preferably, the laser controls the speed and precision of movement of micro- and nano-sized objects by controlling its repetition frequency and single-pulse energy.

[0015] Preferably, the observation and capture module is divided into two types: inverted and upright. The inverted observation and capture module includes a telescope system, a folding mirror, a first semi-transparent and semi-reflective mirror, a first objective lens, a first concave filter, and a first imaging module arranged in sequence. The upright observation and capture module includes a telescope system, a folding mirror, a second semi-transparent and semi-reflective mirror, a third semi-transparent and semi-reflective mirror, a second objective lens, a second concave filter, and a second imaging module arranged in sequence. The telescope system is used to change the size of the captured light spot according to the size of the micro / nano object. The folding mirror is used to select the type of observation and capture module. The first, second, and third semi-transparent and semi-reflective mirrors are used to redirect the excitation light. The second and third semi-transparent and semi-reflective mirrors are also used to introduce illumination light. The first and second objective lenses are used for real-time imaging and observation, and also to focus the captured beam to form a light trap-like structure at the dry solid interface, thereby capturing the micro / nano object.

[0016] Preferably, the motion control module includes a first scanning galvanometer and a second scanning galvanometer, and a two-dimensional electric displacement stage; the first and second scanning galvanometers are used to change the position of the light spot to achieve precise capture and motion control of micro-nano objects within a small area, and the two-dimensional electric displacement stage is used to change the position of the dry solid interface, thereby changing the relative position of the micro-nano object and the captured light spot to achieve capture and motion control of micro-nano objects within a large area.

[0017] Preferably, the micro / nano object comprises nanowires and nanosheets of arbitrary shape, wherein the length of the nanowire or the side length L of the nanosheet satisfies 1 μm ≤ L ≤ 2D. sopt D sopt To capture the diameter of the light spot.

[0018] Preferably, the contact mode between the micro / nano object and the dry solid interface is point contact, line contact, or surface contact.

[0019] Preferably, the dry solid interface is the interface between a gaseous or vacuum environment and a solid substrate.

[0020] Preferably, the solid substrate is a rigid substrate and does not absorb the pulse output signal from the laser driving module.

[0021] Preferably, the dried solid interface includes a planar surface and a curved surface.

[0022] A method for manipulating micro- and nano-objects on a drying interface, comprising the following steps, using the aforementioned photothermal tweezers device for drying interfaces to manipulate micro- and nano-objects on the drying interface:

[0023] 1) Based on the light absorption characteristics of the material, select the output wavelength of the laser, adjust the laser through the signal generator and the optical power control module, and output the pulse signal with the required frequency and power;

[0024] 2) Adjust the size of the captured light spot using the telescope system according to the shape and size of the material;

[0025] 3) Depending on the substrate, inverted or upright optical paths can be selected using a folding mirror to capture and manipulate micro- and nano-objects;

[0026] 4) The laser forms a light spot with a light field gradient distribution on the surface of a dry solid interface substrate through the first or second objective lens, thereby driving and capturing micro- and nano-sized objects.

[0027] 5) The object surface information is observed in real time using the first imaging module or the second imaging module. The position of the light spot is changed by the first scanning galvanometer and the second scanning galvanometer, and the micro-nano object moves accordingly, thereby realizing the capture and motion control of micro-nano objects in a small area. Alternatively, the position of the dry solid interface substrate is changed by the electric displacement stage, thereby changing the relative position of the micro-nano object and the light spot, so that the micro-nano object moves accordingly, thereby realizing the capture and motion control of micro-nano objects in a large area.

[0028] The beneficial effects of this invention are as follows: The photothermal tweezers device and method for manipulating micro / nano objects at a drying interface are simple in structure, easy to assemble, low in cost, highly compatible with existing optical tweezers equipment, and have a wide range of applications. Furthermore, compared to traditional optical tweezers, this invention also has advantages such as low excitation power, high control precision, fast response speed, and no thermal damage. Existing micro / nano object manipulation technologies often require special conditions, including a liquid environment, special substrates (micro / nano fiber surfaces – reducing contact area), or structured materials (coating the interface surface with a phase change material – surface lubrication), to reduce friction and thus achieve the driving of micro / nano objects on a solid interface. This invention can directly overcome the solid interface resistance to drive, capture, and control the motion of micro / nano objects, thus exhibiting greater versatility and scalability. Due to the stable capture characteristics of this invention, the motion of micro / nano objects can be completely controlled by the movement of the light spot, achieving free movement of micro / nano objects in a two-dimensional plane. Existing technologies often only achieve driving, lacking further control over motion, or are limited to one-dimensional motion. Therefore, this invention has greater flexibility and universality. Attached Figure Description

[0029] Figure 1This is a schematic diagram of the photothermal tweezers device for drying interfaces according to the present invention.

[0030] Figure 2 Photographs and schematic diagrams of the optical sequence of the oblique nanowire orbital change motion of the present invention;

[0031] Figure 3 This is a schematic diagram illustrating the principle of the rotational motion of the obliquely placed nanowires of the present invention;

[0032] Figure 4 This is an optical sequence diagram of the axial motion of the flat nanowires of the present invention;

[0033] Figure 5 This is a schematic diagram illustrating the axial motion principle of the flat nanowires of the present invention;

[0034] Figure 6 This is an optical sequence diagram of the radial motion of the flat nanowires of the present invention;

[0035] Figure 7 This is a schematic diagram illustrating the radial bending principle of the flat nanowires of the present invention;

[0036] Figure 8 This is an optical sequence diagram of the nanosheet motion of the present invention. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0038] This invention utilizes the common photothermal effect to convert the light energy of a pulsed laser acting on a micro / nano object into the material's own thermal energy, causing rapid internal thermal expansion. This transient thermal expansion energy creates an impact load within the material, known as photothermal shock. During the pulse duration, the photothermal shock can deposit sufficient energy within the micro / nano object to generate a significant force or acceleration, overcoming interfacial resistance and allowing the micro / nano object to achieve net displacement at the dry solid interface, thus driving the micro / nano object. By keeping the laser spot stationary and continuously applying the pulsed laser, the micro / nano object can be continuously driven until it reaches a position of internal force equilibrium, thereby achieving capture of the micro / nano object. When relative motion occurs between the laser spot and the micro / nano object—that is, when the laser spot or substrate moves (driving the micro / nano object)—the micro / nano object will move accordingly until it returns to its original captured state (i.e., the position of internal force equilibrium), thus achieving motion control of the micro / nano object. Furthermore, an electric displacement stage is used instead of manual operation to achieve stable, persistent, and highly reciprocating motion control.

[0039] A photothermal tweezers device is proposed to drive, capture, and control the motion of micro- and nano-objects at a dry solid interface. Depending on the excitation conditions, it can drive, capture, and control the motion of micro- and nano-objects on the dry interface, performing rotational, axial, and radial movements, respectively.

[0040] like Figure 1 The schematic diagram shown is of a photothermal tweezers device for drying interfaces. The device includes a laser driving module, an observation and capture module, and a motion control module.

[0041] The laser driving module includes a signal generator 1, a laser 2, and an optical power control module 3 arranged in sequence. The signal generator 1 is connected to the laser 2 and is used to generate pulse output signals of different frequencies. The optical power control module 3 is on the same optical axis as the laser 2, receives the optical pulses output by the laser 2, and adjusts the power of the optical pulse signals.

[0042] The observation and capture module is divided into two types: inverted and upright. The inverted observation and capture module includes a telescope system 4, a folding mirror 5, a semi-transparent mirror 7, an objective lens 8, a concave filter 9, and an imaging module 10 arranged in sequence. The upright observation and capture module includes a telescope system 4, a folding mirror 5, semi-transparent mirrors 12 and 13, an objective lens 14, a concave filter 15, and an imaging module 16 arranged in sequence. The telescope system 4 is used to change the size of the capture spot according to the size of the micro / nano object. The folding mirror 5 is used to select the type of observation and capture module. The semi-transparent mirrors 7, 12, and 13 are used to redirect the excitation light. The semi-transparent mirrors 12 and 13 are also used to introduce the illumination light 17. The objective lenses 8 and 14 are used for real-time imaging and observation, and also to focus the captured beam to form a light trap-like structure on the surface of the substrate 19 to capture the micro / nano object.

[0043] The motion control module includes scanning galvanometers 6 and 11 arranged in sequence, and a two-dimensional electric displacement stage 18. The scanning galvanometers 6 and 11 are used to change the position of the light spot to achieve precise capture and motion control of micro-nano objects in a small area. The two-dimensional electric displacement stage 18 is used to change the position of the substrate 19, thereby changing the relative position of the micro-nano object and the captured light spot to achieve capture and motion control of micro-nano objects in a large area.

[0044] The light pulse output by the laser drive module is sent into the telescope system 4. After the light spot size is adjusted, the light shines on the folding mirror 5. For inverted observation: the light reflected by the folding mirror 5 enters the semi-transparent mirror 7 in the inverted observation capture module after the light spot is adjusted by the scanning galvanometer 6. The reflected light passes through the objective lens 8 and is focused on the surface of the substrate 19. The transmitted light enters the concave filter 9 and is captured by the imaging module 10. For upright observation: the transmitted light from the folding mirror 5 enters the semi-transparent mirror 12 in the upright observation capture module after the light spot is adjusted by the scanning galvanometer 11. The light is reflected to the semi-transparent mirror 13. The reflected light passes through the objective lens 14 and is focused on the surface of the substrate 19. The transmitted light enters the concave filter 15 and is captured by the imaging module 16. The illumination light 17 shines on the semi-transparent mirror 12 and passes through the semi-transparent mirror 13.

[0045] The introduction of illumination light 17 provides conditions for real-time observation, enabling the observed field of view to obtain uniform and sufficient illumination, and can be placed on any optical axis that requires supplemental lighting.

[0046] In some embodiments, laser 2 is a nanosecond laser, but it is not limited to this. Picosecond lasers, femtosecond lasers, or even modulated long-pulse lasers can all meet the driving conditions with pulse widths within the range of 50 fs to 100 μs. Furthermore, the speed and precision of movement of micro- and nano-sized objects can be controlled by adjusting the repetition frequency and single-pulse energy (output power) of laser 2.

[0047] In some embodiments, the wavelength of the laser 2 is 532 nm, but it is not limited to this. The laser wavelength is the absorption wavelength of the manipulated micro-nano object, that is, the driving conditions can be met in the range of 300 nm-2 μm.

[0048] In some embodiments, the manipulated material is a gold nanomaterial, but it is not limited to this. Most photothermal absorbing materials can meet the driving conditions, such as metallic materials and semiconductor materials.

[0049] In some embodiments, the manipulated object is shaped as a one-dimensional linear or a two-dimensional arbitrary sheet structure. By changing the area of ​​the light spot or the size of the light power, the length of the nanowire can be extended from one or two micrometers to tens of micrometers, and the area of ​​the nanosheet can be extended from a few square micrometers to thousands of square micrometers.

[0050] The second aspect of this invention provides a method for using the photothermal tweezers device for driving, capturing, and controlling the motion of micro- and nano-objects at a dry solid interface. Three specific embodiments are given below to illustrate the method steps of this invention in detail. Specific Implementation Example 1:

[0052] A method for manipulating obliquely placed nanowires at solid interfaces using photothermal punching tweezers:

[0053] like Figure 2As shown, metal nanowires are randomly distributed on a silica substrate. Due to the dihedral shape of the nanowire ends, some nanowires can stably tilt onto the substrate using these dihedral angles. Under irradiation with a 532nm nanosecond laser with a spot diameter of 10μm, a repetition frequency of 100Hz, and an average power of 0.5μW, a 3.7μm long tilted gold nanowire rapidly leaves the center of the laser spot. After reaching the point of equilibrium (the point of force balance) where the spot captures the nanowire, it rotates in a quasi-circular shape (approximately 6.5μm in diameter). The tilted nanowire can be moved to any specified position on the substrate by changing the laser spot or substrate (moving the sample) one orbit at a time (similar to satellite orbit changes), thus manipulating the rotational motion of the tilted nanowire.

[0054] Figure 3 This is a schematic diagram illustrating the rotational motion principle of the tilted nanowire. When the first half of the laser pulse acts on the nanowire, initiating thermal shock, the temperature at the contact point between the gold nanowire and the quartz substrate rises by 150K, causing the nanowire to begin thermal expansion. At this time, the expansion at the lower left contact point is hindered by interfacial friction, while the suspended tilted end generates extremely high acceleration (10⁻⁶ K) under the thermal shock. 7 m / s 2 ) and strain rate (10 5 s -1 Therefore, the expansion of the material can push the suspended end to the upper right, such as... Figure 3 As shown in (a). During the latter half of the laser pulse's action, due to inertia, the tilted end maintains its original motion state, as shown in (a). Figure 3 As shown in (b). Even though the nanowires have a very small mass, the enormous acceleration generated by thermal shock will still cause the material to generate a corresponding thermal inertial force F. int F int The horizontal component is used to overcome the maximum static friction, pulling the contact end to slide on the substrate towards the inclined end; while the vertical component is used to reduce the contact force, thereby reducing the maximum friction force, so that the inclined nanowire produces a net displacement.

[0055] like Figure 3 As shown in (c), under continuous pulsed light, the nanowire exhibits a corresponding temperature gradient due to the influence of the pulse intensity gradient. Because of this internal temperature gradient, the nanowire generates a thermal gradient mass density F. grd The net thermal gradient force F can be obtained by integrating the entire nanowire by volume. Ngrd It includes one component toward the hot contact end and another component toward the center of the light spot, the latter providing the force to adjust the axis.

[0056] In F int and F NgrdUnder the combined effect of these factors, the nanowires can continuously adjust their state during movement, always remaining perpendicular to the light intensity gradient curve, i.e., the isointense lines (a curve formed by points in all directions with equal light intensity centered on the light spot). Figure 3 As shown in (d). Specific Implementation Example 2:

[0058] A method for axially manipulating flat nanowires at solid interfaces using photothermal punching tweezers:

[0059] like Figure 4 The diagram shows the optical sequence of the axial movement of a flat nanowire. A 532nm nanosecond laser with a spot diameter of 8.6μm, a repetition frequency of 100Hz, and an average power of 0.9μW irradiates the right end of a 10.1μm long flat gold nanowire. The nanowire gradually moves towards the spot until the center of the nanowire and the center of the spot roughly coincide, at which point the nanowire stops moving. The average speed of the nanowire during the entire process is approximately 1.3nm / pulse.

[0060] Figure 5 This is a schematic diagram illustrating the principle of axial movement of a flat nanowire. Figure 5 (a) shows the thermal absorption distribution of gold nanowires under laser irradiation, with the left end referred to as the cold end and the right end as the hot end. When a flat nanowire is subjected to pulsed laser irradiation, the thermal shock generated at the hot end cannot be conducted through thermoelastic conduction during the pulse duration (equivalent to a force F). Npro This affects the cold end, causing a thermal gradient force F within the nanowire. Ngrd The acceleration was not offset in time, resulting in an extremely high acceleration (10⁻⁶) at the center of the nanowire towards the hot end. 8 m / s 2 ) and strain rate (10 5 s -1 This causes a net displacement of the nanowires towards the hot end, such as... Figure 5 (b) Under continuous pulse action, the gold nanowire continues to move until its center roughly coincides with the center of the light spot, at which point the thermal gradient force density F at various points in the nanowire is measured. grd It is balanced, such as Figure 5 (c) When the substrate moves slowly along the nanowire axis, the nanowire remains trapped in the center of the light spot. Therefore, the nanowire slides axially on the substrate in the direction of the light spot. This method can be used to manipulate the axial movement of the nanowire. Specific Implementation Example 3:

[0062] A method for axial manipulation of flat nanowires at a solid interface using photothermal punching tweezers:

[0063] like Figure 6As shown, under the specific conditions described above, the average power of the 532nm nanosecond laser is further increased to 1.2μW and irradiated at the center of the 10.1μm gold nanowire, where the center of the nanowire and the center of the laser spot roughly coincide. The nanowire gradually bends and deforms, moving away from the center of the laser spot until it roughly coincides with the isointense line (an isointense line is a curve formed by points of equal intensity in all directions centered on the laser spot). Under continuous pulse action, when the substrate moves slowly in the opposite direction of the nanowire's bending (i.e., towards the laser spot), the gold nanowire remains trapped by the laser spot at its isointense line position. Therefore, the nanowire undergoes radial sliding on the substrate towards the laser spot. This method can be used to manipulate the radial movement of the nanowire.

[0064] Figure 7 This is a schematic diagram illustrating the principle of radial bending deformation of a flat nanowire. The thermal gradient force density F within the nanowire... grd As the average power increases, the pressure on the two ends of the nanowire increases, causing it to gradually overcome the lateral friction and begin to bend and deform until it bends to the point where the nanowire is in equilibrium with the force inside, i.e., the bending curvature of the nanowire coincides with the intensity lines of the light spot. Specific Implementation Example 4:

[0066] A method for manipulating nanosheets at solid interfaces using photothermal tweezers:

[0067] like Figure 8 As shown, a 532nm nanosecond laser with a spot diameter of 8.2μm, a repetition frequency of 8kHz, and an average power of 180μW irradiates a 46.3μm area. 2 The gold nanosheets are positioned at the edge of the light spot and move towards it until they reach a point of equilibrium. At this point, the center of the nanosheet is close to the center of the light spot. When the substrate is moved, the nanosheet is still captured by the light spot and moves accordingly, thus achieving control over the movement of the nanowires. The movement of the gold nanosheets in different directions can be manipulated by selecting the irradiation edge. Furthermore, during the manipulation of the gold nanosheets, a smaller nanosheet is simultaneously pushed and controlled to move a longer distance at one end. Therefore, this method can be used to indirectly manipulate another micro / nano object.

[0068] The metal and semiconductor micro / nano materials are prepared by vapor deposition, and materials grown by other methods (such as liquid phase growth) can also be driven.

[0069] The light source is spatial light, which may be replaced by fiber laser.

[0070] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A photothermal tweezers device for drying interfaces, characterized in that, The device is used to drive, capture, and control the motion of micro- and nano-objects at a dry solid interface. It includes a laser driving module, an observation and capture module, and a motion control module. The laser driving module generates a pulse output signal with adjustable frequency, variable power, and switchable wavelength. The observation and capture module observes and captures the micro- and nano-objects in real time. The motion control module controls the positional relationship between the micro- and nano-objects placed on the dry solid interface and the capture spot generated by the observation and capture module. The laser driving module includes a signal generator, a laser, and an optical power control module arranged in sequence; the signal generator is connected to the laser and is used to generate pulse output signals of different frequencies; the optical power control module is on the same optical axis as the laser, receives the optical pulses output by the laser, and adjusts the power of the optical pulse signals. The observation and capture module is divided into two types: inverted and upright. The inverted observation and capture module includes a telescope system (4), a refracting mirror (5), a first semi-transparent mirror (7), a first objective lens (8), a first concave filter (9), and a first imaging module (10) arranged in sequence. The upright observation and capture module includes a telescope system (4), a refracting mirror (5), a second semi-transparent mirror (12), a third semi-transparent mirror (13), a second objective lens (14), a second concave filter (15), and a second imaging module (16) arranged in sequence. The system (4) is used to change the size of the captured light spot according to the size of the micro-nano object. The folding mirror (5) is used to select the type of observation and capture module. The first semi-transparent and semi-reflective mirror (7), the second semi-transparent and semi-reflective mirror (12) and the third semi-transparent and semi-reflective mirror (13) are used to realize the direction of the excitation light. The second semi-transparent and semi-reflective mirror (12) and the third semi-transparent and semi-reflective mirror (13) are also used to introduce the illumination light. The first objective lens (8) and the second objective lens (14) are used for real-time imaging and observation. At the same time, the captured light beam is focused to form a light trap-like structure on the dry solid interface to capture micro-nano objects. The motion control module includes a first scanning galvanometer (6) and a second scanning galvanometer (11), and a two-dimensional electric displacement stage (18). The first scanning galvanometer (6) and the second scanning galvanometer (11) are used to change the position of the light spot to achieve precise capture and motion control of micro-nano objects in a small area. The two-dimensional electric displacement stage (18) is used to change the position of the dry solid interface, thereby changing the relative position of the micro-nano object and the captured light spot to achieve capture and motion control of micro-nano objects in a large area.

2. The photothermal tweezers device for drying interfaces according to claim 1, characterized in that, The laser can be a nanosecond laser, a picosecond laser, a femtosecond laser, or even a modulated long-pulse laser, with a pulse width within the range of 50 fs–100 μs, all of which meet the driving conditions.

3. The photothermal tweezers device for drying interfaces according to claim 2, characterized in that, The laser has a wavelength of 532nm, which is the absorption wavelength of the manipulated micro-nano object, meaning that the driving conditions are met within the range of 300nm–2μm.

4. The photothermal tweezers device for drying interfaces according to claim 2 or 3, characterized in that, The laser controls the speed and precision of movement of micro- and nano-sized objects by controlling its repetition frequency and single-pulse energy.

5. The photothermal tweezers device for drying interfaces according to claim 4, characterized in that, The micro / nano objects include nanowires and nanosheets of arbitrary shapes, wherein the length of the nanowires or the side length L of the nanosheets satisfies 1μm≤L≤2D. sopt D sopt To capture the diameter of the light spot.

6. The photothermal punching tweezers device for drying interfaces according to claim 4, characterized in that, The contact methods between the micro / nano objects and the dry solid interface are classified as point contact, line contact, or surface contact.

7. The photothermal punching tweezers device for drying interfaces according to claim 1, characterized in that, The dry solid interface is the interface between a gaseous or vacuum environment and a solid substrate.

8. The photothermal tweezers device for drying interfaces according to claim 7, characterized in that, The solid substrate is a rigid substrate and does not absorb the pulse output signal from the laser driving module.

9. The photothermal punching tweezers device for drying interfaces according to claim 7, characterized in that, The dried solid interface includes planar and curved surfaces.

10. A method for manipulating micro / nano objects on a dry interface, characterized in that, Manipulating micro / nano objects on a drying interface using any of the photothermal tweezers devices for drying interfaces as described in claims 1 to 9 specifically includes the following steps: 1) Based on the light absorption characteristics of the material, select the output wavelength of the laser, and adjust the laser through the signal generator and optical power control module to output a pulse signal with the required frequency and power; 2) Adjust the size of the captured light spot using the telescope system (4) according to the shape and size of the material; 3) Depending on the substrate, the inverted or upright optical path is selected through the folding mirror (5) to capture and manipulate micro- and nano-objects; 4) The laser forms a light spot with a light field gradient distribution on the surface of the dry solid interface substrate through the first objective lens (8) or the second objective lens (14), thereby driving and capturing micro and nano objects; 5) The object surface information is observed in real time using the first imaging module (10) or the second imaging module (16). The position of the light spot is changed by the first scanning galvanometer (6) and the second scanning galvanometer (11), and the micro-nano object moves accordingly, thereby realizing the capture and motion control of micro-nano objects in a small area. Alternatively, the position of the dry solid interface substrate is changed by the electric displacement stage (18), thereby changing the relative position of the micro-nano object and the light spot, so that the micro-nano object moves accordingly, thereby realizing the capture and motion control of micro-nano objects in a large area.

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