| The mechanics sensitive unit as a key part of mechanical detection technology,have beenwidely applied in the filed of aerospace, geological exploration, medical equipment and everyaspects of production and life.In recent years, with the development of nano technology,especially the research and development metal nanostructure bulk effect and high sensitiveproperties. Combined with physical quantum tunneling mechanism of the nanocomposites, thenano composite materials with high mechanical, electrical, biochemical sensitive have becomeresearch focus of researchers all over the world.As semiconductor materials, ZnO has a goodpiezoelectric and piezoresistive properties, has been widely used in power generation, nanosensing research,its sensitivity factor is about1～2order of magnitude higher than metal.Socombine the high sensitivity characteristic of nanostructures and high sensitivity facto of ZnO,the ultra high sensitive detection of the mechanics parameter could be realized.A polydimethylsiloxane(PDMS)-Zinc oxide copolymer was successfully prepared byultrasonic mix method in this paper and accelerometer structure Was trial-produced accordingto the optimized stress sensitive film, using Zinc oxide powder as filler particles andpolydimethylsiloxane(PDMS) as matrix．The preparation technics，microstructure，stresssensitive characteristics properties of ZnO／PDMS composite film were studiedsystematically．Then，the measuring technique for the stress sensitive characteristics of thecomposite film were designed step by step．On this basis，the stress sensitive characteristicsof the composite film under different accelerometer was studied. The composite films withexcellent stress sensitive property were optimized through a large number of experiments.Finally, Accelerometer structure Was trial-produced according to the optimized stress sensitivefilm．The main results are as follows：（1）On the respect of composite film preparation: sensitive composite film wasresearched and developed based on Zinc oxide powder as filler particles andPolydimethylsiloxane(PDMS)as matrix and the ultrasonic technology condition30℃×2h, Andpolydimethylsiloxane(PDMS)-Zinc oxide copolymer was successfully prepared.respectively．The effects of filler surface modification on the stress sensitivecharacteristic of Zinc oxide／PDMS composite film were studied，Such problems as uniformdispersion of Zinc oxide powder into the PDMS matrix, The experimental research verifiesthat change the ratio between ZnO and PDMS could adjust the electronic transportproperties,stress resistance and capacitance well, and provides some new research ideas for theapplication of different force-sensitive sensor technology based on such type of force-sensitivematerials.（2）On the respect of construction methods and the stress sensitive characteristics ofcomposite film: Film microstructures is investigated by scanning electronic microscopy(SEM)JSM-6700F. the micrographs showed that Zinc oxide powder in PDMS matrix with gooddispersity, and interweaved with each other homogeneously, Such problems as uniformdispersion of Zinc oxide powder into the PDMS matrix, We design firstly a new stress loadingsystem to obtain the sensitive nature, including an Agilent4156C semiconductor characteristicanalyzer and an Agilent4284A precision impedance characteristics analyzer.The experimental research verifies that the stress sensitive characteristics of the composite filmare excellent when the test frequency is100KHz, The stress sensitivity of Zinc oxide thecomposite film increases with the increase of the density. By measuring the resistance、capacitive and GF values of Zinc oxide powder in a polydimethylsiloxane(PDMS) matrix.The stress sensitive characteristics of Zinc oxide composite film of composite thin films istested and the piezoresistive sensitivity factor reaches40and pressure capacitive sensitivityfactor reaches70in the experiment. The Zinc oxide composite film with excellent stresssensitivity. The key factors to affect the stress-capacitive and stress-resistance characteristic ofthe Zinc oxide composite film are powder content and the size．(3) In the aspect applies: First，sensitive element of accelerometer sensor is designed, thedevice stress sensitive characteristics tests of the accelerometer sensor are conducted．Themeasured results shows the sensitivity of the accelerometer is up to0.48pF／g，the feasibilityof the composite film is applied in the accelerometer.for sensitive accelerometer based on thestructure of composite thin film force effect validation laid the foundation theory and test. The Zinc oxide composite film is in accord with the essential requirements of stresssensitive sensor, which is expected to become a new potential generation of sensitive materialwith excellent application prospect．... |
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