Research On Wireless Power Transmission Technology Of Biological Implantable Device Based On Magnetoelectric Effect

The advancement of modern medical equipment has greatly improved people’s quality of life.As an extension of wearable devices,biological implantable devices have the advantages of small size,convenient use,real-time and accurate monitoring of the health of living organisms,and effective prevention and treatment of specific diseases compared with traditional medical devices.The biggest technical bottleneck facing biological implantable devices is the lack of reliable power supply.At present,most of these devices use mature lithium battery technology,and the battery needs to be replaced by surgery after the power is exhausted,which will increase the pain and economic burden of patients.Wireless power transmission technology can transmit energy in a non-contact manner,and has the characteristics of safety and reliability.However,existing wireless power transmission technologies such as inductive coupling and ultrasonic have certain technical problems,which restrict the application of wireless power transmission technology in biological implantable devices.To this end,this paper proposes a wireless power transmission technology for biological implantable devices based on the magnetoelectric effect.Through the structural design,simulation and experimental analysis of components,the rational use mode and feasibility of the proposed technology are systematically studied,and laid the foundation for its application.The main research contents of this paper are as follows.This paper summarizes and analyzes the application and research status of wireless power transmission technology in the field of biological implantable devices,and clarifies the problems faced by this technology on this basis.Based on the analysis of the principle of magnetoelectric effect and the equivalent circuit model of magnetoelectric composite materials,the paper puts forward the concept of wireless power transmission technology for biological implantable devices based on this effect,and discusses its specific technical scheme.The magnetoelectric transducer is the executive element of this technology,and its magnetoelectric properties directly affect the efficiency of energy transmission.To this end,the thesis builds a magnetoelectric performance testing system,designs and fabricates magnetoelectric transducers,and uses experimental testing methods to study the effects of magnetic field application,piezoelectric materials,excitation modes,external organization and packaging on device performance.The feasibility of the scheme is verified.Furthermore,the paper designs a self-clamping magnetoelectric transducer device for implantation applications,and uses COMSOL finite element software to carry out simulation analysis of the device performance,and compares the magnetoelectric output characteristics of the three structural schemes included.And analyze the internal causes of its results.On the basis of the above work,the thesis fabricated a self-clamping magnetoelectric transducer prototype device for biological implantation.The performance of bias magnetic field,magnetoelectric voltage coefficient and output linearity are compared and studied,and the optimal structure scheme is obtained to achieve the maximum magnetoelectric voltage output.The authors further prepared a magnetoelectric transducer prototype device based on the optimized scheme.The power supply and load capacity test and the energy harvesting test under mechanical excitation were carried out in the simulated biological environment to evaluate its energy conversion ability and actual power supply efficiency.The experimental results show that the self-clamping magnetoelectric transducer prototype device made based on the optimized scheme exhibits good power supply and load carrying capacity in the simulated biological environment.It works under a 5Oe alternating magnetic field for 603 s,charges a 9400μF capacitor to 5.293 V,and stores132 m J of energy in the capacitor.It can drive 12 parallel LEDs to emit light for 16 s,or maintain a commercial thermometer and hygrometer to work normally for 61 s.At the same time,the device works under 4Hz mechanical vibration for 600 s,can charge the680μF capacitor to 1.764 V,and stores 1.07 m J of energy in the capacitor.The device finally realizes the wireless power transmission under the excitation of external magnetic field and the collection and storage of external vibration energy.The research of this thesis is expected to play a positive role in breaking through the bottleneck of sustainable power supply technology for biological implantable devices.