Fundamental Research On Pressure Sensitive Hall Element

In the science and technology of national defense system,narrow surface structure between the layers exists in some large equipment.It's required to measure the internal stress and magnetic induction intensity,but the traditional sensor can't meet the above situations.However,silicon rubber filled with a small amount of carbon nanotubes can form effective conductive network and ensure good flexibility at the same time.It's sensitive to pressure and can be used as a flexible pressure transducer.It combines with hall sensor to constitute a pressure sensitive hall element which can realize double parameters measurement of stress and magnetic induction intensity and save space and cost.Therefore,the thesis mainly focuses on the electrical properties of pressure-sensitive hall element and makes the pressure sensitive magnetic sensor for one component become possible.Besides all above,a further step is taken to improve the sensitivity of the element and so on.The main tasks are summarized as follows:(1)The pressure sensitive hall element was got and experimental platform in line with the requirements was achieved;(2)The stress-magnetic experiments(deformation:0.1mm?0.4mm;magnetic induction intensity:50Gs?550Gs;current value:0.5mA?1.5mA)was performed;(3)How the magnetic induction intensity,current,mass ratio,pressure sensitive hall element structure influenced hall voltage-stress-time characteristics was obtained.The hall voltage change value increases as the pressure or current value is raised and it decreases as the mass ratio value is larger;(4)How the stress,current,mass ratio,pressure sensitive hall element structure influenced the hall voltage-magnetic induction intensity-time characteristics and absolute magnetic field sensitivity was derived.The magnetic field sensitivity decrease as the mass ratio increases and goes the opposite trend as the current value increases;(5)How the circuit inside the hall element of conduction worked according to the above phenomenon and the experimental data was got;(6)The conversion method among the hall voltage,magnetic induction intensity and stress was acquired.According to the experimental results,the feasibility that pressure sensitive hall element can measure stress and magnetic field is preliminary verified.It's important to make the manufacture process better to improve the sensitivity and solve other issues.At last,the magnetic field sensitivity is no less than 2.5?V/Gs.