c is the viscosity coefficient of liquid in the micro-nano cavity, rho is the density of the liquid in the micro-nano cavity, V is the driving speed of the electric transfer platform when laser bound particles start to move at a constant speed along with the micro-nano cavity, and S is the sectional area of the microspheres.

Compared with the prior art, the optical tweezers realization and measurement device and the optical tweezers force measurement method have the beneficial effects that: the method can visually observe that the laser can form a gradient force optical trap to bind micro particles in the solution in the micro-nano cavity, and the measurement of the optical tweezers force on the microspheres with specific sizes can enable the actual optical tweezers force of the laser with fixed power with large final energy parameters to be known; the method provides help for selecting laser power when optical tweezers are used for objects with different sizes such as cells, yeasts and the like in other researches in the future; the force of the optical tweezers is directly measured by a balance method, and is irrelevant to the laser energy loss of the whole optical path, so that the precision and the reliability of the force measurement of the optical tweezers are greatly improved.

[ description of the drawings ]

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 is a graph illustrating a force analysis of laser-bound particles according to an embodiment of the present invention;

the figures in the drawings represent:

100 optical tweezers realization and measurement device;

1-a laser; 2-a first lens; 3-a second lens; 4-a spectroscope; 5-an objective lens; 6-micro nano cavity; 7-electric transfer platform; 8-CCD camera; 9-display.

[ detailed description ] embodiments

Example (b):

referring to fig. 1-2, the present embodiment is an optical tweezers implementing and measuringapparatus 100, which includes a laser 1, a first lens 2 and asecond lens 3 for expanding and shaping a light beam emitted from the laser 1, a beam splitter 4 for receiving the light beam emitted from thesecond lens 3 and reflecting the light beam downward to enter anobjective lens 5, amicro-nano cavity 6 located below theobjective lens 5, anelectric transfer platform 7 for driving themicro-nano cavity 6 to move horizontally, a CCD camera 8 located above the beam splitter 4 and located on the same optical bus as theobjective lens 5, and a display 9 electrically connected to the CCD camera 8.

Liquid with known density is contained in themicro-nano cavity 6, microspheres are put in the liquid, and the diameter of each microsphere is 0.5-15 mu m.

Thesecond lens 3 can be adjusted in the position of three X, Y and Z axes by a three-axis adjusting and driving mechanism (not marked in the figure), the adjustment of the X axis can effectively adjust the bright spots of the optical trap and the imaging of the microspheres on the same horizontal plane, the adjustment of the Y axis and the Z axis can enable laser to enter the objective lens in a more collimated manner, a better gradient force optical trap is formed, and then the focusing point and the imaging point are effectively connected.

In this embodiment, the laser 1 is a red laser with a wavelength of 650nm, and has a strong contrast ratio and a clearer display and observation. But the thermal effect is obvious, for the active cells, lasers with other wavelengths such as 976nm and the like can be selected, but the adjustment difficulty is larger because the lasers are not in the visible light wave band. Therefore, a 650nm red laser is preferable.

Light beams emitted by a red laser 1 are expanded and shaped by a light beam coupler consisting of a fixed first lens 2 and a position-variablesecond lens 3 and then enter a spectroscope 4, the laser is reflected downwards by the spectroscope 4 and enters anobjective lens 5, and the laser is focused by theobjective lens 5 and then enters amicro-nano cavity 6 to form a laser potential well; and the micro particles in themicro-nano cavity 6 are bound through the laser potential well to form the optical tweezers effect. And imaged by the CCD camera 8 above and finally displayed on the display 9. Because the red laser is adopted, the optical tweezers phenomenon can be directly observed.

In the embodiment, the CCD and the display are combined to be a tool for displaying the effect of the optical tweezers, so that the observation is more convenient; the electric transfer platform is used as a carrier of the micro-nano cavity, so that a power source for uniform motion at different speeds is realized, and conditions are provided for calculation of optical tweezers force.

The embodiment also provides an optical tweezers force measuring method based on the optical tweezers implementing and measuring device, which comprises the following steps: starting theelectric transfer platform 7 to drive themicro-nano cavity 6 to rotate at an initial speed V₀Starting to move at a constant speed, and observing whether the microspheres in the liquid move along with the constant speed through a display to judge whether the particles are caught by the laser; if the particles do not move, the particles are effectively bound by the laser, the movement speed of themicro-nano cavity 6 is increased by a set speed increment delta V (for example, 1 μm/s), whether the laser bound particles move along with the micro-nano cavity is observed again, if the laser bound particles do not move, the movement speed of themicro-nano cavity 6 is continuously increased until the laser bound particles move along with themicro-nano cavity 6 at a constant speed, at this time, the movement speed V of themicro-nano cavity 6 is recorded, and a calculation formula of the optical tweezers force F of the laser bound particles is as follows:

The initial velocity V0 should be as small as possible, and it is not possible to move the microspheres at once initially, and thus cross the optical tweezers force, and the specific magnitude of the optical tweezers force is unknown.

After the particles are captured by the laser, theelectric transfer platform 7 is started to drive themicro-nano cavity 6 to move at a constant speed, and the speed is adjustable. According to the principle of relative motion, themicro-nano cavity 6 can be regarded as immobile, and the laser bound particles move horizontally at a uniform speed. The force balance principle of a uniform-speed moving object is that the small ball is dragged to move horizontally by optical tweezers force F, and meanwhile, the small ball is subjected to resistance F, gravity G and buoyancy N of liquid, so that F is F, and G is N. Resistance to laser-bound particles

Which is equivalent to optical tweezers force.

In the embodiment, a Newton's first motion law is used as a design principle, a driving transfer platform is designed, a micro-nano cavity is placed on the transfer platform, liquid with a known density is filled in the micro-nano cavity, microspheres with a known diameter are placed in the liquid, then an optical tweezers implementation device generates optical tweezers into the micro-nano cavity, the micro-nano cavity is moved at a set speed, whether the microspheres are effectively grabbed by the optical tweezers is observed through a display, and the set speed is as low as possible so as to ensure that the optical tweezers can effectively grab the microspheres; after the optical tweezers effectively grasp the microsphere, the moving speed of the micro-nano cavity is gradually increased until the microsphere moves along with the micro-nano cavity at a constant speed, the moving speed of the micro-nano cavity at that time is recorded, and then the optical tweezers force received by the microsphere is equal to the resistance of liquid to the microsphere according to the Newton's first motion law, so that the optical tweezers force can be accurately calculated, the measurement accuracy of the optical tweezers force is greatly improved, and the measurement method is more scientific and reasonable.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

Translated fromChinese

1.一种光镊实现与测量装置，其特征在于：其包括激光器、对所述激光器发出的光束进行扩束整形的第一透镜与第二透镜、接收所述第二透镜射出光束并向下反射进入一物镜的分光镜、位于所述物镜下方的微纳腔、驱动所述微纳腔实现水平移动的电动移载平台、位于所述分光镜上方且与所述物镜位于同一光学母线上的CCD相机、以及与所述CCD相机电连接的显示器；所述第二透镜受三轴调节驱动机构驱动进行XYZ三轴的位置调整。1. A kind of optical tweezers realizes and measures device, it is characterized in that: it comprises laser, the first lens and the second lens that the beam that described laser sends out beam expanding and shaping, receives described second lens and emits beam and downward A beam splitter that is reflected into an objective lens, a micro-nano cavity below the objective lens, an electric transfer platform that drives the micro-nano cavity to move horizontally, a beam splitter located above the beam splitter and on the same optical bus as the objective lens. A CCD camera and a display electrically connected to the CCD camera; the second lens is driven by a three-axis adjustment drive mechanism to adjust the position of the XYZ three-axis.

2.如权利要求1所述的光镊实现与测量装置，其特征在于：所述激光器为波长为650nm的红光激光器。2 . The optical tweezers realization and measurement device according to claim 1 , wherein the laser is a red laser with a wavelength of 650 nm. 3 .

3.如权利要求1所述的光镊实现与测量装置，其特征在于：所述微纳腔内盛放有已知密度的液体，所述液体中放入有微球。3 . The optical tweezers realization and measurement device according to claim 1 , wherein the micro-nano cavity contains a liquid of known density, and the liquid contains microspheres. 4 .

4.如权利要求3所述的光镊实现与测量装置，其特征在于：所述微球的直径为0.5～15μm。4 . The optical tweezers realization and measurement device according to claim 3 , wherein the diameter of the microspheres is 0.5-15 μm. 5 .

5.一种基于权利要求3所述光镊实现与测量装置的光镊力测量方法，其包括：启动电动移载平台带动所述微纳腔以初始速度V₀开始匀速运动，并通过显示器观测液体中的微球是否随之运动来判断激光是否抓住了粒子，若粒子未移动，则说明激光有效束缚了粒子，然后以设定的速度递增量ΔV增加微纳腔的运动速度，再次观测激光束缚粒子是否随之移动，以此类推直到激光束缚粒子随着微纳腔一起匀速运动，此时记录微纳腔移动的速度V，则激光束缚粒子的光镊力F的计算公式如下：5. An optical tweezers force measurement method based on the optical tweezers implementation and measurement device of claim 3, comprising: starting an electric transfer platform to drive the micro-nano cavity to start a uniform motion with an initial speed V₀ , and observing through a display Whether the microspheres in the liquid move along with it can be used to judge whether the laser has caught the particle. If the particle does not move, it means that the laser has effectively bound the particle, and then the speed of the micro-nano cavity is increased by the set speed increment ΔV, and observe again. Whether the laser-bound particles move along with it, and so on until the laser-bound particles move at a uniform speed with the micro-nano cavity. At this time, the velocity V of the micro-nano cavity moving is recorded, and the calculation formula of the optical tweezer force F of the laser-bound particles is as follows:

其中，C为微纳腔内液体的粘滞系数，ρ微纳腔内液体的密度，V为让激光束缚粒子随着微纳腔一起开始匀速运动时电动移载平台的驱动速度，S为微球截面积。Among them, C is the viscosity coefficient of the liquid in the micro-nano cavity, ρ is the density of the liquid in the micro-nano cavity, V is the driving speed of the electric transfer platform when the laser-bound particles start to move at a uniform speed with the micro-nano cavity, and S is the micro-nano cavity. Ball cross-sectional area.