Research On The Mechanism And Application Of A High-performance Flexible Pressure Sensor

Flexible pressure sensors have broad application prospects in health monitoring,human-computer interaction,wearable electronic devices,and electronic skin.High sensitivity and wide measurement range are often difficult to achieve simultaneously in pressure sensors.In this paper,a flexible capacitive pressure sensor using a composite film of graphene oxide（GO）and low-dimensional nanomaterials as a dielectric layer was constructed,on the one hand,low-dimensional nanomaterials are used to construct convex microstructures for interlayer modification of layered GO films,one the other hand,low-dimensional nanomaterials form a single layer in BP/GO@BP/BP sensor.The synergy of microstructures solves the contradiction between sensor sensitivity and measurement range,enabling the sensor to achieve performance goals such as extremely low minimum detection limit,wide measurement range,and high sensitivity;and establishes the relationship between the morphology characteristics,mechanical properties and sensor performance of different microstructured materials.The relationship between them is obtained.The specific research contents are as follows:（1）Construction of four flexible capacitive pressure sensors with different microstructure materials as dielectric layers,wherein the dielectric layers are thin films of GO with layered microstructures,thin films of GO mixed stack layers decorated with zero-dimensional material carbon spheres（CS）spherical protrusions（GO@CS）,thin films of GO mixed stack layers decorated with two-dimensional material black phosphorene（BP）nanpsheets protrusions（GO@BP）,and on the basis of the hybrid stacked GO@BP structure,constructed a sandwich composite film（BP/GO@BP/BP）with loose BP nanosheets at the bottom,a mixed-stacked GO@BP intermediate layer,and a clustered BP nanosheet at the top,it was prepared by self-assembly.（2）Establish the relationship between different microstructure morphological characteristics,mechanical properties and sensor performance.Specifically,the electrical performance test of the four sensors can be obtained.GO,GO@CS,GO@BP pressure sensor have a very wide measurement range of 0 k Pa-8800 k Pa,and the BP/GO@BP/BP sensor has a wide measurement range of 0 k Pa-242 k Pa,and the minimum detection limit can reach 0.588Pa.The order of maximum sensitivity of each sensor is SBP/GO@BP/BP>SGO@BP>SGO>SGO@CS.According to the characterization analysis of microscopic morphology,under the action of pressure,the loose BP layers at the bottom and top are most prone to deformation,resulting in the highest sensitivity of the sensor,but at the expense of a certain amount of measurement range;the second is the GO@BP structure;the third is layered GO structure;the GO@CS sturcture is relatively least prone to pressure deformation,the reason may be that the strength of CS nanospheres is high.The stress-strain mechanical characteristics analysis shows that under the same pressure,the change of the distance between the upper and lower electrode plates of the four sensors is（35）d _BP/GO@BP/BP>（35）d _GO@BP>（35）d _GO>（35）d _GO@CS,which is consistent with the above microscopic mechanism.The research results show that the sensors proposed has the performance characteristics of wide measurement range,high sensitivity,specially,the BP/GO@BP/BP sensor has the performance characteristics of low minimum detection limit（0.588 Pa）,good high-pressure resolution at the same time.An effective method is provided for the development of high-performance flexible pressure sensing devices.In addition,demonstrate the application of various scenarios from tiny pressure to extremely high pressure.The results show that the BP/GO@BP/BP sensor can have broad potential application prospects in the fields of human health monitoring,wearable electronic devices,robotics,real-time communication and so on.