Micro Hybrid Energy Harvester Circuit for Biomedical Application

The deployment of energy harvester as a power supply attracts high attention especially for micro-scale devices. It is utilizing the ambient energy sources to produce electric energy. In-depth research has been carried out to achieve energy harvester with high efficiency and sensitivity. Three energy sources are used as input which are thermal energy, vibration and Radio Frequency (RF). The thermal energy input is in the form of DC voltage while RF and vibration is in the form of AC voltage. All these inputs are set to 0.02 V, 0.5 V and -20 dBm respectively. The operation frequency that has been used for vibration input is 10 Hz while for RF input is 915 MHz. The full - wave rectifier circuit is used to convert AC to DC vibration signal. Meanwhile, the voltage multiplier circuit is constructed by implementing substrate modulation techniques to multiply the input voltage. All these individual circuits are combined using the voltage adder circuit to form a complete hybrid energy harvester system. The energy harvester circuit is built and simulated using PSPICE software with the resistor load of 1 MΩ. The complete energy harvester circuit with hybrid input has successfully achieved output voltage approximately 2.12 V and suitable for use as an alternative power supply to biomedical device applications. The device is Health Monitoring device that requires minimum supply source of 1.7 V.