Surface Tension Confined Droplet Microfluidics-the Research Of A New Method To Fabricate Materials With High Throughput

Surface tension confined microfluidic technology has a wide range of applications in materials,chemistry,biology,etc.The use of facile and efficient methods for high-throughput preparation of microdroplet arrays is a hot area for surface tension confined microfluidics in recent years.With the development of microfluidics technology and the limitations of traditional experimental methods,it is urgent that microfluidics technology replace traditional experimental methods.We also hope that all of these processes can be miniaturized into one chip.The microfluidic experimental method not only realize the high-throughput materials synthesis,characterization and testing,but also facilitates the development of the integrated,miniaturized,automated and portable platforms.First of all,this paper focuses on the fabrication of droplet arrays with a simple,high-throughput,controllable method with low-consumption.The content includes the preparation of the pre-patterned surface,the process of droplet generation,the scope of application of the method,the influencing factors of the droplet volume,and the lateral size scaling effects during discontinuous dewetting.Millions of droplets can be produced in a few seconds with this method(up to 375KHz),and can be effectively controlled for the position,geometry and volume of the droplets.It is important for the applications such as material synthesis,drug screening,crystals preparation.We systematically explore the influencing factors of the droplet volume,including the size of the droplets,the viscosity of the liquid,and sliding speed.In this process,we find the corresponding relationship between the lateral size of the droplet and contact angle,at the same time,propose and define the lateral size scaling effect during discontinuous dewetting.This phenomenon is explained by the process of droplet generation.We also study the effect of droplets sizes on the evaporation mode,and verify by aggregation-induced emission materials.As novel porous materials-Metal Organic Framework materials have a wide range of applications in gas storage,sensing,catalysis,and molecular separation.In this work,we use a sliding method to fabricate MOFs single crystals during discontinuous dewetting with high-throughput,and precisely control the morphology of crystals and growth orientation by tuning the sliding speed,and also synthesize MOFs crystals in different sizes.The growth of MOFs crystals in the droplets with different size further validates the effect of droplets sizes on the evaporation mode,which provides a new development direction for the study of functional materials in the futureMicrolens and microlens arrays(MLAs)have wide applications in various fields,including light-emitting devices,sensors,fiber-coupling devices,vertical cavity surface emitting lasers(VCSEL),microfluidic system and so on.The demand of MLA with precise shape has increased over the last few decades.In this work,we use sliding method for high-throughput fabricating droplet arrays with low consumption and the utilization of a sliding method to create MLA with confined position and size.We describe a controllable sliding method for fabricating millions of isolated femto-to nanoliter-sized droplets with defined volume,geometry and position and a speed of up to 375 kHz.In this work,without using a superhydrophobic or superoleophobic surface,MLAs are instantly formed on the patterned substrate by sliding a strip of liquid along the substrate,which exhibit good ability to focus light.Because both shape and size of the final microlens can be controlled by the pre-pattern and the speed of sliding,it is possible to define MLAs with different imaging properties.Particularly,both the simulations and experimental measurements in optical properties are carried out,demonstrating that microlenses with shapes beyond a hemisphere exhibits higher light utilization efficiency and wider viewing angleBased on the surface tension confined microfluidic chips,we also try other applications,including the synthesis of metal nanomaterials with the alignment platforms,the preparation of polymer microparticles and the synthesis of coordination polymers.We use the alignment platform to realize the synthesis and screening of gold nanoparticles,and prepared gold with different morphologies on the same chip;The preparation of microparticles using photoresist and PLGA is also realized on the chip by sliding method.It's the basis of functional preparation of microparticles;in addition,we also try the growth of coordination polymers on the chip to verify the feasibility and to afford a basis for the growth and synthesis of materials.Although the parameters of the experiment need further optimizations,it provides the basis and possibility to replace the traditional laboratory with microfluidic chips.