Design And Preparation Of Flexible Pyroelectric Cell Devices

The flexible pyroelectric detector based on organic polymer materials has a simple preparation process and small thermal conductivity.It is suitable for preparing large-scale integrated devices.The flexible pyroelectric detector has become a research hotspot in recent years.The work of this paper revolves around the structure of pyroelectric detector cell device.The influence of sensitive element structure and support structure on the performance of the device is studied through the simulation of the finite element software COMSOL system.At the same time,the film preparation process of the PVDF with surface structure is preliminarily explored.Firstly,the surface structure parameters were simulated and optimized,and the effects of different structural parameters on the thermal properties of sensitive metamaterials were analyzed.COMSOL is used to establish a two-dimensional model,and systematically analyzed the influence of surface structure on the thermal performance of PVDF-sensitive units.Then two kinds of three-dimensional finite element models were carefully designed and constructed,and the effects of surface structure on the surface thermal properties of sensitive elements were analyzed more comprehensively.After compared with non-structural sensitive elements,it came to a conclusion that when the sensitive element has an inclined wall trench structure,the surface temperature change rate of the sensitive element is 117.7%higher than that of the flat plate structure.Secondly,this paper introduces the microphonic effect in PVDF pyroelectric detector.The influence of the support structure on the stress of the sensing element was analyzed by COMSOL simulation.A supporting structure with five columns were designed and constructed.The inhibition of the piezoelectric interference voltage due to the microphonic effect was studied through simulation.The support structure of the substrate has performed a comparison analysis with the between thermal and mechanical.The influence of supporting column structural parameters on the suppression of micro effect in sensitive cells is analyzed,and the optimal structural parameters are obtained.It is concluded that when the sensitive element of the inclined wall trench structure is supported by the five-support column structure,the thermal performance is only lost by 25%,and in the meanwhile the piezoelectric interference voltage is also reduced by 49.3%.Finally,a mold with a surface structure was successfully prepared,as well as a PVDF-sensitive unit with a surface structure on the mold by casting or scraping the film.The influence of the preparation process on the film formation quality was also analyzed.Aluminium was vacuum-evaporated to produce electrodes and the device response rate was measured by a test system.When the sensing element has an inclined wall trench structure,and its trench width and trench spacing are both 300?m,the device response rate is 2.69×10~3V/W,which is 63.2%higher than the PVDF film without surface structure.It is proved that the surface structure of PVDF film has a significant improvement effect on its pyroelectric properties,which lays a solid foundation for the structural structuring and large-scale integration of PVDF-based flexible pyroelectric detectors.