Study On Automatic Control Technology Of Optical Tweezers In Single-molecule Force Spectroscopy Measurement System

Over the last four decades,optical tweezers have become a more and more sophisticated tool and been extensively used in a large variety of scientific disciplines.Especially in life science,optical tweezers have many advantages such as non-contact,non-damage and high precision,thus making it very suitable for biological cells,proteins research and promoting the development of the quantitative biology.Optical tweezers,which are based on the mechanical action of light,utilize a highly converged laser beam to capture micro beads,and apply acting force with the magnitude of piconewtons to the trapped object.Combining with the back focal plane(BFP)detection techniques,optical tweezers have the ability to measure the piconewtons force.So optical tweezers have both the ability of fine control and precision measurement,and the development of optical tweezers technology has mainly focused on the two aspects.Dual optical tweezers configured with one laser beam splitting are designed for high-precision single-molecule force spectroscopy measurement.This paper aims at improving the efficiency of technology segment with manual operation or receptive tasks,achieving the automated testing of optical tweezers,and promoting the further promotion of optical tweezers.The main works and achievement in this paper are list below,1.The improvement on instrument and application development status of optical tweezers are reviewed.Some approaches of motorized optical tweezers are list and their advantages and disadvantages are compared.Then,the necessity of motorized improvement for our dual optical tweezers system is analyzed.2.The dual optical tweezers with differential detection system is built,the key parameters in the design of the system and some details in the process of building optical path are discussed and the hardware used for automated testing is configured.3.The software of automated testing for optical tweezers is finished.Then the major algorithms of image process and control strategy are analyzed.Further,the test of capturing particles dynamically is conducted.4.The phenomenon of receptive trapping in a single optical trap,which have a significant impact on the efficiency of the force spectra experiment,is analyzed and a video process method is adopted to discern two or more particles residing along the axial direction in a single optical trap.5.The system performance is verified by experiment.Firstly,the conjugation structure in the optical system is tested,and then performance of electrical system is verified through the power spectrum analysis of the key equipment.Finally,the automatic features of the software is verified.