Design And Optimization Of Magneto-elastic Sensor Detection Instrument

The magneto-elastic sensor is a new type of biochemical sensors, use the giantmagnetostrictive material(GMM) as the substrate, coating modification on thesubstrate. Coating materials is sensitive to the measured object, the change of themeasured object will cause the change of resonance parameters. Analysis the changeof sensor’s resonance parameters used for the measurement of biochemistry field,such as the analysis of chemical substances, concentration and chemical reaction ratedetermination, determination of the concentration of biological enzyme and activityanalysis.Magneto-elastic sensor is based on the magnetostrictive principle of magneticmaterial, when the AC drive magnetic field applied along the sensor axial, due to themagnetostrictive effect, the incentive of the magnetic field can be converted intomechanical elastic energy, the generated elastic energy will force the magneto-elasticsensor vibration along its length direction; due to the inverse magnetostrictive effect,forced vibration of sensor affect its magnetization state, thus the detection coil canmeasure the forced vibration by induced current. Measure the induced output signal,we can analysis the resonance parameters of the magneto-elastic sensor, and theparameters will change when the coating materials change.Sweep detection method is used to measure the parameters of the magneto-elasticsensor. Applied alternating excitation magnetic field with known frequency range onthe magneto-elastic sensor, when excitation signal frequency equal to the sensor’sfrequency, the forced vibration of magneto-elastic sensor will induce the maximumcurrent and amplitude, we can analyze the sensor’s resonance parameters by theoutput signal.Using embedded ARM-Linux architecture to design the magneto-elastic sensordetector, measure the sensor’s resonance parameters, it also provide a portablesolution for the detector. Magneto-elastic sensor excitation system and detectionsystem design needs to consider the actual magneto-elastic sensor measurementstructure, it will helpful of rapid and accurate completion of the measurementfunctions.Magneto-elastic sensor’s resonance parameters not only related to its surfacecoating material, the excitation signal will have an impact. DC bias magnetic field can eliminate the "multiplier" effect of magnetic materials, applied DC bias magnetic onthe magnetic materials will cause pre-stretching, but the amount of size (related to theDC bias magnetic) will affect the vibration of the magneto-elastic sensors, thus affectthe resonance parameters, a reasonable DC bias magnetic field will makemagneto-elastic sensor reach minimum resonant frequency, and it will improve theconversion efficiency of the magnetic machine system; However, reasonable DC biasmagnetic field varied of magnetoelastic sensor’s size, to solve this problem, develop amethod to select optimal DC bias magnetic field, that can reduce the influence of ΔEeffect and magnetic anisotropy changes, to ensure that the measurement process iskept in the same optimal state.