Research On Multi-dimensional Piezoelectric Sensor Based On CMOS

In recent years,with the development of electronic skins,wearable portable electronic devices,and intelligent robots,various functional sensors have received considerable attention.At present,the research on single-functional sensors such as temperature sensors,pressure sensors,and vision sensors has achieved excellent results.Most of the research results have been commercialized.However,a single-functional sensor can often only realize one function,which limits its application scope.It is difficult to meet the requirements of modern electronic devices for the sensor's multidimensionality,versatility,flexibility,portability and portability.Therefore,this paper proposes a piezoelectric / pyroelectric / capacitive multidimensional sensor based on PVDF-TrFE and PLLA film prepared on a large area TFT array,which realizes the detection of dynamic three-dimensional forces,temperature changes,and quasi-static forces.Capacitive sensing can achieve high-precision visual representation of quasi-static forces(theoretical resolution of 50?m)to give multi-dimensional sensors visual perception.This multi-function sensor greatly expands the applications of the sensor.The specific research work is as follows:Firstly,starting from sensitive materials,this paper analyzes the superiority of piezoelectric / pyroelectric thin films,and elaborates its piezoelectric effect and pyroelectric effect in detail.The finite element analysis software COMSOL Multiphysics was used to simulate the response from multidimensional sensors with different structures to pressure,temperature,and both pressure and temperature.Through analysis,it is found that: 1.The piezoelectric signal of the multi-dimensional sensor increases proportionally with the thickness of the piezoelectric film.However,as the thickness of the film increases,the degree of increase in the piezoelectric signal ?V gradually decreases.Therefore,in the process of preparing the piezoelectric film,the thickness of the film should be increased as much as possible within the process allowable range,so as to improve the sensitivity of the piezoelectric film;2.With the structure of the multidimensional sensor unchanged,the signal generated by the piezoelectric film is proportional to the applied pressure load and has a high sensitivity to external stimuli.The piezoelectric signal generated by a force of 0.01 N is 0.3 V;3.By setting the film surface to different temperatures,it can be seen that the greater the temperature change rate of the film,the greater the voltage generated,the temperature rises by 15 ° C,and a signal of 0.1536 V is generated.The finite element analysis laid the foundation for the preparation and theoretical analysis of multi-dimensional piezoelectric sensors;Secondly,the structure design and manufacturing process of piezoelectric /pyroelectric sensors based on PVDF-TrFE,piezoelectric / capacitive sensors based on PLLA,and multi-dimensional piezoelectric sensors combining them are studied in detail.The conclusions are as follows: 1.The piezoelectric thin film with excellent performance is prepared by the blade coating method;2.The PVDF-TrFE piezoelectric film was polarized in situ by the polarization process,and its piezoelectric coefficient was increased from 1~2 pC/N to 28 pC/N,which greatly improved the sensitivity of multidimensional sensors to dynamic force detection.Finally,this paper builds the multi-dimensional sensor signal detection platforms,highlights the sensing capabilities of multi-dimensional sensors,and analyzes the relationship between external physical signals and the system's electrical output signals.It mainly includes the signal response from multi-dimensional sensors to different pressure stimuli,different temperature,different contour objects.The conclusions are as follows: 1.The piezoelectric signal generated by the multi-dimensional sensor is proportional to the external dynamic force,and can identify the direction of the force and the position of the force;2.The pyroelectric signal generated by the multi-dimensional sensor is directly proportional to the temperature change rate of the film,and the pyroelectric signal generated when the temperature decreases and rises is in the opposite direction,so the temperature change can be accurately judged;3.Multi-dimensional sensors can realize accurate recognition and visual representation of the texture of cicada wing with very small mass.These studies have proved that this multi-dimensional sensor has good sensing performance and has great application development potential in the field of electronic skin.