Study On Nonlinear Vibration Control Of Nano Beam Based On Piezoresistive Effect

With the development of micro sensor technology,piezoresistive sensor has become one of the hotspots of sensor technology research.The piezoresistive sensor with high integration,high precision,miniaturization and lightness has become an important demand product in the sensor market.The traditional signal transmission method of piezoresistive sensor has some defects,such as low detection accuracy,poor anti-interference ability,low signal-to-noise ratio,and parameters are easily affected by the change of environmental conditions.In addition,piezoresistive materials have some problems such as temperature drift,nonlinear hysteresis error and poor stability,which can not meet the requirements of modern high-precision measurement and control technology.Therefore,finding new piezoresistive materials,adopting advanced sensing principles and innovating sensing control methods are the main tasks of micro sensor research,which have important theoretical value and research significance.Firstly,the nonlinear vibration control method based on piezoresistive effect of silicon diaphragm is studied.The vibration differential equation of nano beam with piezoresistive effect of silicon was established.Considering the main resonance,the control factors of nonlinear vibration of nano beam are studied.Then,the time-delay feedback control method is used to solve the nonlinear problem caused by time-delay.This paper focuses on the problem of vibration instability caused by nonlinear vibration of time-delay feedback control system,analyzes the relationship between the parameters of DC and AC excitation source control voltage,damping,closed-loop gain coefficient of feedback system and time-delay parameters,and obtains the influence factors of control and suppression system nonlinearity.Secondly,using carbon nanotube composite as piezoresistive membrane material,the nonlinear vibration control method of nano beam containing carbon nanotube composite piezoresistive sensor control is analyzed.According to the vibration physical model of the piezoresistive effect of the nano beam,the partial differential equation of the system is obtained,the equation is solved,and the amplitude frequency ratio equation of the system input signal and output signal is obtained.According to the amplitude frequency equation,the control factors of nonlinear vibration of nano beam are obtained,and how to keep the nonlinear vibration in a balanced and stable state by adjusting the control parameters is analyzed.Finally,taking Euler-Bornoulli beam as vibration model,a nonlinear vibration control method based on GMR effect is proposed.According to the vibration model,the vibration differential equation with giant magnetoresistance effect is established.Considering themain resonance of the vibration system,the differential equation is solved and the amplitude frequency ratio equation is obtained.According to the analysis of the amplitude frequency characteristic curve,the nonlinearity of the system can be weakened by adjusting the control voltage,damping,closed-loop gain coefficient of the feedback system and the physical parameters of the nano cantilever beam.The results show that the sensors based on piezoresistive effect of silicon,piezoresistive effect of carbon nanotube composite and giant magneto resistive effect of ferrosilicon multilayer have higher accuracy and sensitivity for vibration signal extraction.By selecting appropriate system parameters and control parameters,the nonlinear vibration of the nano beam can be weakened and restrained.