Research On Bionic Magnetic Sensor Based On Salmon Weak Magnetic Sensing Mechanism

With the continuous extension of the application of magnetic field,the detection and application of weak magnetic field are more and more deeply in people’s life.Examples include the search for iron ore 500m underground,aided navigation for geomagnetic surveys,and magnetic imaging applications for biomedicine.Weak magnetic field detection has put forward new requirements for magnetic sensor performance.There are many kinds of magnetic sensors on the market,but they all have certain disadvantages in weak magnetic detection.For example,high sensitivity and small volume cannot be taken into account,large working power and the need for external power supply and so on.At this time,salmon’s highly sensitive ability of weak magnetic field gives researchers new inspiration.To explore the mechanism of salmon’s weak magnetic perception and design a bionic magnetic sensor,which has great application value.Therefore,this thesis takes salmon as a biomimetic template,analyzes the biological structure of salmon magnetic perception,establishes the mechanism model of salmon magnetic perception,and designs and prepares biomimetic magnetic sensor based on it.Finally,the performance index of the magnetic sensor is tested.Combined with the excellent performance of the magnetic sensor,the engineering application is carried out.The main research work is as follows:（1）The biological experiment of salmon weak magnetic perception was concluded,the biological structure of salmon weak magnetic perception was analyzed,and the complete biological process of salmon magnetic perception was elaborated.By simplifying and abstracting the biological mechanism,the magnetic sensing mechanism model of multi-layer heterogeneous material coupling structure is established,and the magnetic domain,intermediate medium and cell membrane are simulated respectively.The finite element simulation was carried out to analyze the influence of important parameters on the overall stress conduction of the model,and it was found that the presence of the medium layer would reduce the stress conduction effect,which revealed that the direct coupling structure between the magnetic domain particles and the cell membrane in the nasal cavity of salmon is the reason for the ultra-high magnetic sensitivity of salmon.On this basis,theoretical modeling analysis was carried out on the force of the model,and the theoretical calculation value was compared with the trend of the finite element simulation,which further verified the correctness of the model and laid the foundation for the design of the bionic magnetic sensor.（2）Based on the mechanism model and combined with the characteristics of biological structure,the magnetic sensitive part of the sensor composed of Terfenol-D and Ni was designed.The Piezoelectric ceramics（PZT）material was selected as the signal reading layer to complete the preparation of the bionic magnetic sensor.Finally,the performance of the prepared magnetic sensor is tested.The experimental results show that the sensor sensitivity is as high as 10^-9T,and the output linearity is 0.98.The sensor can maintain a stable output in continuous 8 hours of work,and has good durability.Bionic magnetic sensor also has excellent self-bias,can output the maximum voltage at zero bias,completely abandon the external DC bias magnetic field.（3）Combined with the performance advantages of bionic magnetic sensor,such as no external power supply,stable,durability and strong self-bias ability,this thesis finds that it has a huge application possibility in the field of self-power supply.Because the bionic magnetic sensor combines small size with high sensitivity,combined with the excellent performance of magnetic field itself,this thesis applies it in the background of wireless charging of human implant devices,and designs a self-powered charging system with bionic magnetic sensor as energy supply.In the system,in order to know the battery power in time so as to charge the battery,this thesis adds an ultra-low power ZIGBEE voltage wireless transmission module with CC2530 and AT2401C as the core.Finally,the magnetic field environment is built to test the sensor and module to verify its feasibility.In summary,by analyzing the magnetic sensing biological structure of salmon,a magnetic sensing mechanism model of multi-layer heterogeneous material coupling was established in this thesis,and the direct coupling structure between the magnetic domain particles and the cell membrane in the nasal cavity of salmon was revealed to be the reason why salmon has ultra-high magnetic sensitivity.Based on this,the bionic magnetic sensor was designed and prepared.The correctness of the model and sensor design is verified by testing the performance index of the magnetic sensor,and the sensor is applied in engineering,which provides a new idea for the design and application of the bionic magnetic sensor.