| Summary: | 碩士 === 國立臺灣大學 === 應用力學研究所 === 100 === In recent years, according to there are many works focus on biosensing systems and micro-electro-mechanical system, the size of bio-sensor has been decreased enough to implant into human body and achieved real-time medical monitoring. There are two ways of power provide: implanted non-rechargeable batteries and wireless power transfer. However, the implanted battery can’t be prolonged use and the lack of replacement is not easy, this research use of wireless power transmission to provide a sensing system to do for long-term monitoring of energy.
This study use ultrasound to do the concept of power transfer, using piezoelectric transducer exciting the ultrasound into the body and transfer it to electrical energy for the biosensing. Using biocompatible material PDMS to package transducer for implanted into body. Compare the efficiency of different package shapes : spherical, cubic and fresnel for the power transmission. From the experiments, we can find the energy generation by Fresnel packaged is all bigger than the spherical and cubic. While input power is 693.7mW, the average output power of Fresnel is 57.15mW which is larger than spherical as 32.55mW and cubic as 19.7mW. The efficiency of transmission promotes significantly from -13.28dB (spherical) and -15.46dB (cubic) to -10.84dB (Fresnel). According to above results, we concluded the Fresnel shape of packaged receiver is the best for power transmission in human body. Besides, we combine the receiver with voltage double-rectifier. In order to obtain the stable DC output power, the receiver is considered at far field and it is observed the DC power under variable resistance. The experiment results show that the maximum DC power is 24.4mW with 5.1k
|
|---|
