The Theoretical And Experimental Research On Double-chambered Piezoelectric Pump With Four-actuator

In the past decade,MEMS got a lot of progress. Micro-fluid system as an important part of MEMS has made a rapid progress. Micro-pump is the key part of micro-fluid system. Its development indicates the level of Micro-fluid system.Piezoelectric pump,a new kind of transmitting liquid device , is an important application branch of piezoelectric drive whose power is anti-piezoelectric–effect of piezoelectric ceramic. With many merits such as simple structure, small body, no interfering of electromagnetism and good output ability under low applied voltage etc, the piezoelectric pump has very extensive application prospects in the fields of chemistry analysis, medical treatment and bioengineering etc.On the basic of structure characteristics and principle of the piezoelectric pumps which researched by national and other countries, the author put forward a new structure—double-chambered piezoelectric pump with four actuators.The working principle is researched and the factors that effects the capability of the piezoelectric pump are analysed through academic and experimental.1. PrefaceIntroducted the status of study about Micro-pump at home and abroad,also it's problems to be solved now. Showed the structure characters and working principle of piezoelectric pump especially and analysed it's trend of development.2. The vibration analysis and test of bonding circular PZT actuatorIn this chapter, PZT material, piezoelectric effect,anti-piezoelectric effect,vibration mode of PZT bimorph are introduced and geometry equation and constitutive equation of piezoelectric bimorph are given, providing theoretical warrant for PZT bimorph's vibration analysis, At the same time ,the approximate compute for engineering was given by Rayleigh-Ritz. The formula resonant frequency of the piezoelectric oscilla is also provided. Experimental research about the deformation of the piezoelectric vibrator shows: The deformation of piezoelectric bimorph is affected by wave of power supply. Rectangle wave can make biggest deformation, sina wave is bigger than triangle wave .Base on the noise :Rectangle wave is worst, sina wave is better than triangle wave. In anthother way , The supplied voltage and the frequency of the signal affect the deformation of piezoelectric bimorph too. Vibrator deformation increase with the supplied voltage increase,there is a good linear relationship between them.3. The working principle and theory analysis of piezoelectric pumpTo provide a gist for the design of optimized piezoelectric pump,The index for assessing the output performance of the Piezoelectric pump is summaried.The output pressure and flow of the single-chambered piezoelectric pump are theoretically calculated.The type of the micro- valves used on the piezoelectric pump is introduced,the working characteristics of the umbrella rubber valve and the hysteresis of passive valves are theoretically analysed. On the basis of systemic analysis to the basic unit of multi- chambered piezoelectric pump—single-chambered piezoelectric pump, a double-chambered piezoelectric pump with four actuators is prospered designed and manufactured.A detailed analysis of the pump's work principle is provided. The basic theory of hydromechanics related with PZT pump is expounded.It provides that the mutation of the structure should be avoided or reduced to decrease local energy lose and improve PZT pump's output ability .4. Experimental research about double-chambered piezoelectric pump with four actuatorsA double-chambered piezoelectric pump sample with four actuators is designed and manufactured used plexiglass.From the relevant experimental research,some test conclusions are drawn as follows :1,Multi-cavity structure of piezoelectric pump is conducive to raising the response frequency of the micro-valve, thereby increases the pump's output performance.2,The double-chambered piezoelectric pump sample with four actuators suit to work under the higher frequency.In the operating frequency scope, the corresponding current capacity and the pressure has the optimum working frequency spot to enable its value of exports to achieve in a big way, but the two frequency does not superpose.3,The output performance of piezoelectric pump increases along with the input voltage increasing.The optimum working frequency does not change along with the input voltage change.4,Increasing driver numbers (number of work oscillator) will be able to effectively improve the capability of piezoelectric pump.5,For four oscillators are involved in the case,the pump works best when symmetric oscillators work synchronously and ipsilateral oscillators work asynchronously.The testing results show that the maximum flowrate achieved is up to 1500ml/min at the applied voltage of 150v with frequency of 200 Hz in the conditions of zero pressure of the output,the maximum pressure obtained is 77kPa at voltage of 150v with frequency of 280Hz.5. The utility of PZT pump—Computer Chip Cooling System Driven by Piezoelectric PumpThe heat sink and radiator's dimensions are calculated based on heat transfer knowledge.The computer chip cooling system which is high integration is designed and manufactured. Testing of the prototype shows: the cooling system sample has lower noise, high cooling performance and need short time to reach thermal balance. At ambient temperature of 24℃,it used 18 minutes to reach thermal balance when heating power is 100W,the temperature of thermal balance is 54℃.It need 25 minutes to reach thermal balance when used traditional cooling method and the temperature of thermal balance is 65℃. This shows that the cooling system driven by piezoelectric pump has a good application prospects.