Research And Application Of Micro-nanofluidic Manipulation System

Microfluidic chips are the hotspot in the development of micro-analytical systems and have wide application prospects of biology,chemistry,medicine and others.To improve the property of the microfluidic chips,the nanofluidic control systems with small scale and large specific surface area is embedded into the chip with microchannels forming a micro-nanofluidic chip.In this paper,a low cost and short-cycle method for fabricating separated micro-nanofluidic chips is studied.However,in order to fabricate the micro and nano channels on different chips,a kind of microassembly system is needed.Aiming at the alignment requirement of separated micro-nano fluidic chip,the observation resolution,assembly stress and pre-bonding base performance of micro-assembly system are analyzed and studied.Ultimately,dark field lighting is selected to observe the micro channel and nano channel in the chip with the minimum line width up to 1?m and the minimum depth up to50 nm.In order to reduce the assembly stress,the method of vacuum adsorptionis adopted to fix the nano chips.According to the size of the chip,material and weight factors,two vacuum suction with 6mm diameter rubber are selected,and the method of clamping the side surface of magnet is employed to fix the chips.Dramatically the operation is simple and convenient.In order to solve the prebonding problem between the chip with microchannels and the chip with nanochannels,the prebonding base with aluminum alloy and the resistance wire is designed.An alignment system including microscope unit,vacuum suction unit and alignment regulatory unit is constructed and an assembly method referred to "fixing a chip with microchannels and moving a chip with nanochannels" is adopted.The effective pixels of the inverted biological microscope utilized in the microscopic observation unit for the assembly system are up to 2.01 million,which can clearly collect the images of micro channel and nano channel.Mobile adjustment unit manual 3d micro mobile platform in the direction of the three-dimensional mechanical feeding are 6.5 mm,the accuracy of 0.01 mm,manual rotation of micro mobile platform of coarse tuning range is 360°,fine adjustment range is 6.5 °,precision is0.0167 °,it meets the demand of chip channel on schedule on time and accuracy,and effectively integrates three-dimensional movement and horizontal rotation operation at an organic whole.Consequently the assembly system integration is improved,with the operating space enhanced.simultaneously,a pre-bonding base with a radius of 55 mm the assembly is invented for the assembly system,which effectively realizes the direct pre-bonding operation after chip alignment and avoids the issue of relative position movement during chip transfer.In this paper,a chip with microchannels and a chip with nanochannels are fabricated,the width and the depth of the micro channel is 200?m and 30?m respectively,and the width and depth of the nano channel is 5?m,and 200 nm respectively,and the alignment assembly of glass micro-nanofluidic chips are completed through using the assembly system and assembly method.The system has the advantages of low cost and easy operation.In addition,in order to verify the performance of the chip and the practicability of the system,an ion enrichment experiment is carried out.The results of the experiment show that the assembly system and assembly method can be used to fabricate the micro-nanofluidic chips,and the performance of chips is fine.Compared with other micro-assembly system,the proposed assembly system has the advantages of low cost,flexible operation,high integration and direct pre-bonding.