Design And Preparation Of Editable Microfluidic Chip

Microfluidic chip is a device that integrates basic operation units such as sample preparation,reaction,separation,and detection in the biological,chemical,and medical analysis processes.In the past few decades,microfluidic chips have been widely used in the fields of analytical chemistry,biosensing,cell culture,and material preparation due to their good maneuverability.However,microfluidic chips still have problems such as complicated and time-consuming manufacturing,difficulty in in-situ control of the flow path structure and internal environment.In order to solve the above problems,in this article,we have developed a new type of liquid-phase microfluidic chip based on the "liquid volume block" strategy.By in-situ construction,connection and interruption of multiple droplet "units" on a specific substrate,the rapid preparation of complex microfluidic chips and the in-situ editing of the flow path structure are realized.On this basis,we also use photoactive smart gel materials to achieve in-situ,non-invasive realtime control and detection of the mechanical properties and temperature of the microenvironment in the chip.The specific research content is as follows:(1)A microfluidic chip construction method based on the concept of "liquid building block" is proposed,which can quickly construct complex microfluidic chips and modify the flow path structure of the chip in real time.By forming stable droplets on a specific columnar array substrate and directly connecting a large number of droplet units by assembling building blocks,various shapes of flow channels can be constructed,thereby rapidly preparing two-dimensional(2D)or three-dimensional(3D)Channel microfluidic chip.At the same time,due to the deformability of the liquid,the formed fluid channel can be quickly reconstructed as required to meet the adjustment requirements during use.The effects of columnar array substrate parameters such as column diameter,spacing,material surface energy,etc.on the droplet unit and liquid flow channel are studied.Combined with the mechanical analysis of the water-oil interface,the construction principle of the "liquid bulk wood" chip is explained.Demonstrated the application of the chip in chemical microreactors and organ chips.(2)Aiming at the problem that the mechanical properties of the microenvironment in the "liquid building block" microfluidic chip are difficult to control in situ,a method of using light to synchronize the control and detection of microenvironment parameters is proposed.The coumarin group,photonic crystal and gel are combined to prepare the extracellular scaffold material of hydrogel with adjustable hardness.The information of the hardness change of the hydrogel can be displayed by the color change.The scaffold realizes in-situ,patterned light adjustment,and measurement of mechanical parameters of the mechanical properties of the extracellular scaffold material in the microenvironment of the microfluidic chip.The relationship between the morphology and distribution of fibroblasts cultured on the patterned scaffold and the hardness of the substrate was studied.This method can be used to observe and record cell behavior and hardness distribution under the same microscope field of view,making the relationship between cell behavior and substrate properties easy to understand.(3)Based on the proposed concept of "light regulation-light detection",a smart gel cell scaffold that can regulate and detect the microenvironment temperature in the "liquid volumetric wood" microfluidic chip has been developed.Combining reduced graphene oxide with strong near-infrared light absorption,temperature-responsive polyisopropylacrylamide,and photonic crystals,a smart gel that can control the temperature by near-infrared light irradiation and display temperature information in real time with color changes is prepared.The hydrogel is combined with the "liquid bulk wood" chip,and a gel unit with adjustable mechanical properties and temperature can be constructed in the chip,thereby realizing the dynamic adjustment of the performance of the microfluidic chip system.