Micro-nano Particle Manipulation And Sorting In Integrated Optical Fluidic Chip

With the development of modern medicine and biochemistry,related research has reached the molecular level,and researchers increasingly need to analyze and solve problems from a single cell or even the molecular level.Due to the small size of single cells and molecular size,the precision of traditional operation methods can no longer meet the demand,and microfluidic technology has gradually developed.At the same time,how to capture single cells or even molecules,the transport of molecules and the screening of different small molecules have become the hotspots of related research.Conventional aperture technology captures and manipulates micron-scale targets by focusing the laser and using the optical force that focuses to form the spot.However,conventional aperture technology cannot achieve a smaller area of focus due to the diffraction limit of the laser focus itself.This results in a conventional diaphragm that requires higher optical power for manipulation of sub-micron target samples.The traditional diaphragm requires bulky equipment,and it is impossible to batch operate the defects of the target sample.Therefore,when faced with target samples below submicron,new near-field optical particle manipulation techniques are needed.The novel near-field optical particle manipulation technology mainly includes particle manipulation technology based on waveguide near-field optical force,particle manipulation technology based on the optical resonator,and particle manipulation technology based on surface plasmon resonance.The near-field aperture can not only avoid the influence of the laser focusing thermal effect,but also enable the capture,storage,transmission and sorting of nano-scale particles on the optical flow control chip.And the near-field aperture chip structure is small,which is conducive to large-scale integration on the optical flow control chipBased on surface plasmon resonance optical particle manipulation technology,we designed a novel antibody rapid detection chip with nanoparticle as a solid carrier.The chip captures and transports nanoparticles of appropriate size by changing the polarization of the incident light.We use antigenic antibodies to modify nanoparticles of different sizes.The antibody particles can be transported between the ellipse,while the antigen particles can only be dragged and transported by binding to the antibody particles,and then the antibody is determined by identifying the fluorescent label of the antigen particles at the outlet.Our chip design provides a new two-dimensional planar particle sorting scheme.Due to its ability to perform parallel detection,our design provides an attractive solution for rapid,high-throughput microfluidic channel antibody detection.Based on the optical trapping force of evanescent wave at a micro-ring resonator alongside a waveguide,we designed a tunable optofluidic sorting unit for micro-nanoparticles by localized thermal phase tuning.With the change of field build-up factor of the resonator,the depth of trapping potential well as well as the threshold of trapped particle size are adjustable.Furthermore,by considering the Brownian motion of trapped particles from a statistic perspective,we verified the critical trapping threshold of a potential well,which is usually assumed to be 1 kBT.The threshold not only depends on the optical power and particle size but also on the length of the coupling region.Compared with the wavelength tuning mechanism,localized thermal tuning enables large-scale integration of many independent tunable resonators.As a demonstration,we proposed a set of operations with three resonators for nanoparticles manipulation,including sorting,storing and mixing.Our proposed function units are of great importance to on-chip large-scale integration of optofluidic systems.In summary,we have designed two chip structures in this paper.The first chip is based on the gold nano-elliptical structure to realize the manipulation and sorting of two-dimensional plane particles,and the nanoparticle as the carrier can realize the rapid detection of antibody particles.The second chip is based on a ring resonator for capturing,registering,and sorting sub-micron particles,and the structure is based on thermal tuning to manipulate the particles,facilitating large-scale integration of the microrings on the chip.