Study On The Effect Of Surface Effect Of Lithium Niobate Crystal On Mesoscopic Biological Behavior

Lithium niobate crystals have become one of the hot topics in the field of microfluidics because of their excellent spontaneous polarization and photovoltaic effect.In recent years,biophotonic chips have attracted people's attention due to their advantages of miniaturization,intensification,automation,and convenience,such as micro-bioassay,cell adhesion markers,real-time cell manipulation,making biophotonic chips have a broad application prospects.However,there are few reports on the effects of surface effects of lithium niobate crystal on mesoscopic biological behavior within 10 ?m.Therefore,the effects of surface effects on mesoscopic biological behavior of lithium niobate crystals have been studied in depth and systematically in this paper.Firstly,the effects of spontaneously polarized surface charge of lithium niobate crystal and photovoltaic surface charge of lithium niobate crystal on the activity of mesoscopic Escherichia coli were studied.The experimental results show that the spontaneously polarized surface charge of the?C face of lithium niobate crystal and the?C face of lithium niobate crystal has significant effects on the activity of Escherichia coli,and the bacteria have a specific preference for the negative charge on the surface of the crystal;The effect of the surface charge of the lithium niobate crystal on the activity of Escherichia coli was investigated.This effect is more dependent on the UV pre-irradiation power and time.Secondly,in order to explore the effect of the photovoltaic effect of lithium niobate crystal on mesoscopic biological behavior,we built a set of experimental platform that can observe and record experimental data in real time.Based on this experimental platform,the mesoscopic bio-micromanipulation behavior based on photovoltaic effect of lithium niobate crystal was studied in this paper.By comparing the groups of laser irradiation with different wavelength and intensity,it was found that the inhomogeneous electric field formed by laser irradiation on the?C surface of lithium niobate crystal,the inhomogeneous electric field could cause the bacteria in the liquid to be quickly trapped by dielectrophoresis.At the center of the irradiation spot,405 nm laser was selected as the optimal irradiation light source based on photovoltaic effect of lithium niobate crystal for micromanipulation of Escherichia coli.Lastly,the mesoscopic biological transport characteristics based on photovoltaic effect of lithium niobate crystals were studied.405 nm laser was selected as the driving light source.Laser-assisted bio-droplet driving experiments were carried out on lithium niobate crystals?C surface,?C surface and Y surface.The experimental results showed that the driving modes of bio-droplets on different surfaces were different.The driving force of bio-droplets on the lithium niobate crystals?C surface is attractive,while the?C surface of lithium niobate crystal is repulsive.At the same irradiation power,the driving force of the?C surface is larger than that of the?C surface,and the Y surface has both the driving characteristics of the?C surface and the?C surface.In addition,the splitting control of the biological droplets is realized on the Y surface.After the driving process is completed,the bacteria in the biological droplets still show good activity.