Design And Research On The Piezoelectric Pump With Different-Viscosity Liquid

In the past decade, MEMS developed very quickly. As an important branch of MEMS, Micro-fluid system has made a rapid progress. As a key part of Micro-fluid system, the quality of pump can determine the whole Micro-fluid system's quality.Piezoelectric pump is a kind of new transmission fluid device driven by the piezoelectric transducer components. Piezoelectric pump is also a new kind of superior smart materials actuator. There are three parts of Traditional pump-- driving source, transmission parts and pump body. But piezoelectric pump can combine those three parts together. The characters of piezoelectric pump are small size, high precision control fluid, fast response, no electromagnetic noise, low power expending. So these features make piezoelectric pump has a hugeness application in the high-tech field.In this paper is basis on previous studies, we mainly research piezoelectric pump which transit the different viscosity liquids. We discuss the feature of different structure piezoelectric pump which transit the different viscosity liquids.The full dissertation is divided into six chapters, mainly as follows:1. PrefaceThe status of study about Micro-pump at home and abroad were introduced, problems to be solved were introduced either. Showed the structure characters and working principle of piezoelectric pump especially and analyzed trend of development. And put forward the specific requirements for the following paper.2. Analysis and research on the disk of piezoelectric pumpPiezoelectric pump is driven by the piezoelectric disk which is also the electrical energy conversion components. So the research on the piezoelectric disk is very important to the piezoelectric pump. The basic concept of the piezoelectric disk, the basic physical properties of the piezoelectric material and the important performance parameters, including relative dielectric constant, elastic constants, electrical and mechanical coupling coefficient, mechanical quality factor, piezoelectric constant, working condition and constant frequency were studied. The support way, resonant characteristics, vibration way of piezoelectric disk were studied. The static and dynamic states of piezoelectric disk were analyzed. In another way, the supplied voltage and the frequency of the signal affect the deformation of piezoelectric disk too. Vibrator deformation increase with the supplied voltage increase, there is a good linear relationship between them.3. Passiveness valve of piezoelectric pumpPassiveness valve is one of important component of piezoelectric pump. Three kind of passiveness valve (Cantilever valve, Umbrella valve, Wheel valve) were introduced, the produced materials, working principle and structure were introduced either. The virtue and flaw of these valves were introduced. The opening gap, response frequency and flowing characteristics were analyzed; these can be applied in the research of following text. The opening ability of these three valves was tested, and we knew the opening ability of cantilever valve is 1.2kPa, the opening ability of umbrella valve is 0.5kPa, and the opening ability of wheel valve is 0.7kPa. The hysteretic of passiveness valve was analyzed, and the hysteretic numberδ_j was defined. We found out that decreasing the mass or increasing the stiffness of valve could reduce theδ_j.4. Design the structure of piezoelectric pumpDifferent structure of piezoelectric pump has different output feature. The structure of single cavity pump, dual-chamber tandem pump and dual-chamber parallel pump were introduced, and combine with the basic knowledge of mechanics and fluid, we analyzed the viscosity liquid affected on the pump's properties from the theory.The basic concept of viscosity liquid's movement and the fluid state of the fluid in the piezoelectric pump were discussed. The head loss in piezoelectric pump was analyzed. Researching on single chamber pump is the basic analysis of many chambers pump. So the formulae of the output of single chamber pump were given. And the formula of the output of dual-chamber tandem pump and dual-chamber parallel pump were derived from that.5. The research on the feature of piezoelectric pump when it transit different viscosity liquidThe characteristics of the glycerin were given, as the relation of thickness, density, temperature and viscosity. Glycerin solution is constructed using different viscosity of the liquid. The equipment and experimental programs of viscosity experiment were introduced. A simple constant temperature flume was made. And we made a viscosity experiment by using the tow kind of dual-chamber piezoelectric pump. We got a conclusion that the working condition of dual-chamber parallel pump is better than dual-chamber tandem pump from the experiment. And got a relation of viscosity liquid, working frequency and output of pump. Some phenomena which were seen in the viscosity experiment were analyzed and explained. The valve, the height of cavity and the cushion chamber affect on the dual-chamber parallel pump were obtained by one-factor test. A series of different structure dual-chamber parallel pump were made, and comparative tests were carried out repeatedly. The laws of output of dual-chamber parallel pump were obtained, when the one factor was modified. These results could provide references for the further design. The output of dual-chamber parallel pump is 1500ml/min; the max-pressure is 74.2kPa in 110V AC excitation voltage at 50Hz, when the transited liquid is water. When the viscosity is 234 mPa·s, the flux is 32.7 ml/min, and the max-viscosity of the transited liquid is 300 mPa·s.6. ConclusionThe main conclusions were given. The prospect of the research of piezoelectric pump was made, and the orientation of the research was carried out.