| Microfluidic chip fabrication based on thin film pattern cutting and laminating technology is more cost-effective compared with traditional soft lithography methods.It has become a research hotspot in recent years in the field of POCT.A key problem to face in this strategy is to find an appropriate adhesive material that provide firm bonding with no leakage while not giving polluting chemicals to fluids.The laboratory usage ParafilmM is made of paraffin and fiber,with the good features of waterproofness,soft enough for easy cutting,showing adhesive under 40 degrees heat conditions,as well as general easy to get in most parts of the world,making it an ideal adhesive material for microfluidic chip lamination method.Based on this knowledge,we have explored the strategy of mass production of low cost Parafilm M laminated microfluidic chip based on office level equipment,and have optimized the details of manufacturing technology.A variety of pattern tests have been carried out to verify its 2D functionality,as well as the ability to make multi-layer 3D channel structure.Nowadays,we witnessed a lack of supporting equipment for microfluidic chip,both in laboratory environment and on the market.This condition make thin-film laminated chips difficult to enter the ranks of practical products.Due to some characteristics of thin layer chips,potential users will face inconvenience under two scenes.In the first scenario,when the liquid capacity in the chip is less than 10 μL,a reverse suction can be easily caused if the traditional hosepipe connection or pipette gun is used.In order to make a sensitive and multistep immunization reaction,it is necessary to clean up the waste liquid from each reaction step instantly.In this paper,a centrifuge device for micro-amount waste liquid collection is designed and printed by 3Dprinters.A 19 tube parallel capillary tube bundle is used to dip-take the liquid from outlet port when contacted with chip fixture.Waste liquid was then centrifuged out from the capillary tubes,making them emptied again.The purpose of transferring waste liquid out of thin layer chip was realized with least pollution on contact.Under the second scenario,multiple functions were applied to a self-designed device,including thin-layer chips perfusion,adding biochemical reagent to chip,gas washing,and incubating the chip at 37 ℃.Traditional operation was cumbersome and effort consuming with low efficiency.The device is independently designed.Parts were shopped online,shells are custom designed using CAD.A speed-adjustable peristaltic pump is used for infusion.Sampling is operated through a check valve.Mini air pump blowing was powered by 1.5 V battery to drive out liquids from chips.Silicone heating pad was controlled by a chip which is connected to a temperature probe.24 V transformer plug was used for power supply.The size of the device is small enough to be placed in SLR bag.This machine can aid the potential biochemical detection experiments carried on thin film laminated chips.In addition to manufacturing microfluidic chip using new methods and materials,and inventing new machines to simplify the applications,the author also make a deeper discuss on the principle of microfluidic patterning.Based on these ideas,we put forward a new fluid-manipulating strategy: two-dimensional open-up chip with flexible bottom,combined with fixtures with an active micro-pillar pixel array.In the practice experiment of this strategy,108 units of 3 D printed micro pillars with 2 × 2mm size on top surface,and a pattern-free open-up chip with high elastic latex film bottom and glass substrate,work together,showed good pattern display performance.It can be predicted that with the progress of processing technology,pixel accuracy of this kind of device will continue to improve,and micro column manipulation will be automated.This strategy has broad application prospects in the field of microfluidic patterning. |
PDF Full Text Request