CN-116994789-B - Optical heat forceps device for drying interface and control method of optical heat forceps device on micro-nano object

CN116994789BCN 116994789 BCN116994789 BCN 116994789BCN-116994789-B

Abstract

The invention relates to a photo-thermal forceps device for a drying interface and a control method of the photo-thermal forceps device for a micro-nano object, which utilize the photo-thermal effect of the micro-nano object, convert light energy into heat energy under the excitation of pulse laser, so that the interior of the micro-nano object is subjected to rapid thermal expansion, the transient thermal expansion generates rapid impact load to the interior of the object, and photo-thermal shock continuously acts on the micro-nano object within the pulse duration time to deposit enough energy to generate extremely large force or acceleration in the interior of the micro-nano object. The micro-nano object can be directly driven against the resistance of a dry interface by combining the photo-thermal shock effect and the interface friction, and is captured by a similar optical trap formed at the center of a light spot. And then the movement of the micro-nano object is further controlled by changing the positions of the light spots or the substrate. The invention has the advantages of low excitation power, high control precision, high response speed, no thermal damage and the like. The invention has stable capturing characteristic, and can completely control the movement of the micro-nano object by using the movement of the light spot, thereby realizing the free movement of the micro-nano object on a two-dimensional drying interface.

Inventors

GU FUXING
Zhu Runlin
GU ZHAOQI
Shen Tianci
DOU LIN

Assignees

上海理工大学

Dates

Publication Date: 20260512
Application Date: 20230824

Claims (10)

1. The optical heat forceps device for the dry interface is characterized by comprising a laser driving module, an observation and capturing module and a motion control module, wherein the laser driving module is used for generating a pulse output signal with adjustable frequency, variable power and switchable wavelength, the observation and capturing module is used for observing in real time and capturing a micro-nano object, and the motion control module is used for controlling the position relationship between the micro-nano object placed on the dry solid interface and a capturing light spot generated by the observation and capturing module; The laser driving module comprises a signal generator, a laser and an optical power control module which are sequentially arranged, wherein the signal generator is connected with the laser and is used for generating pulse output signals with different frequencies; The observation capture module comprises an inverted type observation capture module and a normal type observation capture module, wherein the inverted type observation capture module comprises a telescope system (4), a foldback mirror (5) and a first half-mirror (7) which are sequentially arranged, a first objective lens (8), a first concave filter (9) and a first imaging module (10), the normal type observation capture module comprises the telescope system (4), the foldback mirror (5), a second half-mirror (12) and a third half-mirror (13) which are sequentially arranged, a second objective lens (14), a second concave filter (15) and a second imaging module (16), the telescope system (4) is used for changing the size of a capture light spot according to the size of a micro-nano object, the foldback mirror (5) is used for selecting the type of the observation capture module, the first half-mirror (7), the second half-mirror (12) and the third half-mirror (13) are used for realizing the steering of excitation light, the second half-mirror (12) and the third half-mirror (13) are also used for introducing illumination light, and the first half-mirror (8) and the second half-mirror (14) are used for focusing and observing the object to form a real-time capture interface, and the micro-nano object is formed at the same time; The motion control module comprises a first scanning galvanometer (6), a second scanning galvanometer (11) and a two-dimensional electric displacement table (18), wherein the first scanning galvanometer (6) and the second scanning galvanometer (11) are used for changing the positions of light spots to achieve accurate capturing and motion control of micro-nano objects in a small range, and the two-dimensional electric displacement table (18) is used for changing the positions of a dry solid interface to further change the relative positions of the micro-nano objects and captured light spots to achieve capturing and motion control of the micro-nano objects in a large range.
2. The optical heat shock tweezer device for dry interface according to claim 1, wherein the laser is a nanosecond laser, a picosecond laser, a femtosecond laser or even a long pulse laser generated by modulation, and the pulse width satisfies the driving condition within 50fs-100 μs.
3. The optical heat shock tweezer device for dry interface according to claim 2, wherein the wavelength of the laser is 532nm, and the laser wavelength is the absorption wavelength of the micro-nano object to be controlled, namely, the wavelength in the range of 300nm-2 μm, and all the laser wavelength meets the driving condition.
4. An optical heat shock tweezer apparatus for dry interface according to claim 2 or 3, characterized in that said laser achieves control of micro-nano object moving speed and accuracy by controlling its repetition frequency and single pulse energy.
5. The optical heat shock tweezer device for dry interface of claim 4, wherein the micro-nano object comprises nanowires and nano-sheets of arbitrary shape, the length of the nanowires or the side length of the nano-sheets L is 1 μm≤L≤2D sopt ,D sopt is the diameter of the capturing light spot.
6. The optical heat shock tweezer device for dry interface according to claim 4, wherein the micro-nano object is contacted with the dry solid interface in a manner of point contact, line contact or surface contact.
7. The optical heat punch device for drying an interface of claim 1, wherein the dried solid interface is an interface where a gas or vacuum environment contacts a solid substrate.
8. The optical heat shock tweezers device for drying interface of claim 7, wherein the solid substrate is a rigid substrate and does not absorb the pulse output signal outputted by the laser driving module.
9. The optical heat punch device for a dry interface of claim 7, wherein the dry solid interface comprises a planar surface and a curved surface.
10. A control method of micro-nano objects on a drying interface is characterized in that, the method for controlling the micro-nano object on the drying interface by adopting the optical heat forceps device for inoculating any one of the drying interfaces according to the claims 1 to 9 comprises the following steps: 1) According to the light absorption characteristics of the materials, the output wavelength of the laser is selected, the laser is regulated by a signal generator and the laser is regulated by an optical power control module, and pulse signals with required frequency and power are output; 2) According to the shape and the size of the material, the size of the captured light spot is adjusted through a telescope system (4); 3) According to the substrate condition, an inverted or upright light path is selected through a foldback mirror (5) to capture and manipulate the micro-nano object; 4) The laser forms light spots with light field gradient distribution on the surface of the dry solid interface substrate through a first objective lens (8) or a second objective lens (14), so that the micro-nano object is driven and captured; 5) The object plane information is observed in real time by utilizing the first imaging module (10) or the second imaging module (16), the light spot position is changed by the first scanning vibrating mirror (6) and the second scanning vibrating mirror (11), the micro-nano object moves along with the light spot position, the capturing and the motion control of the micro-nano object in a small range are realized, or the position of a dry solid interface substrate is changed by an electric displacement table (18), and the relative position of the micro-nano object and the light spot is further changed, so that the micro-nano object moves along with the light spot position, and the capturing and the motion control of the micro-nano object in a large range are realized.

Description

Optical heat forceps device for drying interface and control method of optical heat forceps device on micro-nano object Technical Field The invention relates to a micro-nano object motion control technology, in particular to an optical heat shock forceps device for a drying interface and a micro-nano object control method thereof. Background With the rapid development of technology, various research fields, such as on-chip integration, surface engineering, biomedicine, microelectronics and the like, enter the microminiaturization development stage, and researchers seek more miniaturized and light-weight alternatives, so that the requirement for efficient manipulation of micro-nano objects on a solid friction interface is also accompanied, wherein the traditional optical tweezers, dielectrophoresis, acoustic vortex and the like are powerful tools for manipulating the micro-nano objects. The dry solid interface has a great hindrance to the movement of the micro-nano object, the normal adhesion force and tangential friction force can reach the order of magnitude of micro-cow (10 -6 N), while the classical traditional optical tweezers technology utilizing the mechanical effect generated by the moment transfer during the interaction of light and particles can only generate the optical power of the order of magnitude of flying cow (10 -15 N) to Pinier (10 -12 N), the resistance is not enough to overcome, and the micro-nano object in direct contact with the solid interface is difficult to drive and control, so the related research is often limited to the micro-nano object suspended in the fluid medium. The presence of non-negligible brownian motion in the fluid medium severely limits the capture stability, steering accuracy, driving distance and control duration of such techniques. And conventional optical tweezers and related techniques often require the use of an objective lens of extremely high numerical aperture to focus the spot to form a very strong optical field at the focal point of the objective lens to capture and manipulate the micro-nano object. The high-power spot of high focusing makes the micro-nano object inevitably absorb a lot of laser energy while being manipulated, thereby generating thermal damage. In addition, operation in a liquid environment for a long time causes unavoidable pollution to the handling equipment or the micro-nano objects. In order to drive the micro-nano object at the solid interface, additional conditions are usually required to be met or the micro-nano object is usually required to be carried out in a special environment, such as adopting a curved surface structure of an optical fiber to reduce the contact area, or adopting a method of coating a layer of phase change material on the surface to realize surface lubrication and the like to reduce interface friction, so that laser control technology, such as photo-ultrasonic technology based on a photo-thermal-elastic wave principle and photo-thermal-deformation principle, can be applied to drive the micro-nano object at the solid interface. However, the above methods lack the phenomenon of optical traps in the conventional optical tweezers, so that stable capture of micro-nano objects, not to mention precise control of micro-nano object movement, cannot be realized. Thus, there is a need to develop a device that can directly overcome friction at a dry solid interface to drive, capture and manipulate micro-nano objects to promote the development of related scientific fields. Disclosure of Invention Aiming at the problems that the traditional optical tweezers technology is small in output force, low in operation precision and poor in controllability, and micro-nano object movement cannot be directly driven, captured and controlled on a dry solid interface, the optical heat impact tweezers device for the dry interface and the operation method of the optical heat impact tweezers device for the micro-nano object are provided, the optical heat effect of the micro-nano object is utilized, the optical energy is converted into heat energy under the excitation of pulse laser, so that rapid thermal expansion occurs in the optical heat impact tweezers device, and the transient thermal expansion can generate rapid impact load, namely so-called optical heat impact, on the interior of the object. During the pulse duration, the photo-thermal shock is constantly acting on the micro-nano object, depositing enough energy inside the micro-nano object to create a significant force or acceleration. The micro-nano object can be directly driven against the resistance of a dry interface by combining the photo-thermal shock effect and the interface friction, and is captured by a similar optical trap formed at the center of a light spot. And then the purpose of further controlling the movement of the micro-nano object is achieved by changing the positions of the light spots or the substrate. The invention has the advantages of low excitation power, hig