Design And Research Of Integrated Piezoelectric Driven Micro Fluid Reactor Based On PDMS

This paper proposes an integrated micro-fluid reactor driven by piezoelectricbased on PDMS. It integrates piezoelectric micro-pumps, micro mixing channel,micro reaction channel into a piece of PDMS substrate，which can achieve differentand active mixing mode, overcome the deficiency existing in the current activemicro-fluid reactor, improve the mixing effect and mixing rate under the micro-scalefluidic, and give full play to efficient mixing characteristics of the active micro-fluidreactor. It is a kind of further-initiative and process controlled active micro-fluidreactor. It has more advantages especially in the synthesis for noble metalnano-particles (such as gold, silver, platinum, etc). The main research contents of thispaper are as follows:The reliability for integration of piezoelectric micro-pump settled on themicro-fluid reactor chip was analyzed. The pump bodies of micro-pump were madeand the process and materials (PDMS) for manufacture was the same with that ofmicro-fluid chip reactor. Test of working performance of piezoelectric micro-pumpwas carried out after the assembly processes of the prototype. The results showed thatpiezoelectric micro-pump based on PDMS has a good performance. It can not onlyhandle liquid like water with low viscosity, but also for the high viscosity fluid (suchas gold chloride acid for chemical reaction solution) with good transmissionperformance.The flow mixing status of the micro mixing channel of micro-reactor weresimulated by Fluent and the simulation calculation results were output in terms of datafiles and project files. Project files were imported into Tecplot with post-process to getthe component concentration distribution of mixing channel and data files wereimported into MATLAB to value the mixing degree. Then mixing status underdifferent parameters were evaluated comprehensively and the best structureparameters and working parameters were selected, which can provide basis for themaking of micro reactor.Micro reactor with integrated chip structure was designed based on theoptimizing channel structure parameters and the output performance of piezoelectricmicro pump, and its production process was designed on the basis of traditional microfluid chip technology. Finally, the micro reactor with the machine size for40mm×40 mm×4mm was made in lab, while the micro hybrid chips driven by double cavitymicro pump was in size of50mm×50mm×6mm. The micro reactor fulfilled itsintegration, miniaturization and portable utilize.The micro-fluid reactor made by the author was used to test the synthesis of goldnano particles, which verified the performance of homemade micro-fluid reactor, andproved its advantages in the application of complex chemical reactions, such asprecious metal nano particles. Experiments also proved that regulating the entranceflow rate of piezoelectric micro pump and operating frequency can affect the size andmorphology of the gold nano particles. This paper proved a homemade micro fluidreactor in the feasibility and advantage of controllable synthesis of the gold nanoparticles. Gold nano particles with the size ranged from20nm to70nm in the shape ofball were get when the voltage of micro-pump in20V、30V、40V, workingfrequency in100Hz、200Hz、300Hz. The experiment proved that other factors (suchas the concentration of the reducing agent sodium citrate) can also affect themorphology of gold nano particles synthesized apart from working parameters ofmicro pump. So further research should focus on the experiment and investigation oneffect factors for micro pump apart from the solution ph, and temperature to obtainthe best matching values, so as to make full use of micro fluid reactor homemade forthe controlled synthesis of nano particles.