Design of interdigital structured supercapacitor for powering biomedical devices

Energy scavenging has become an increasingly popular option for powering electronic devices as a long lasting power sources. A MEMS piezoelectric based energy scavenging system consists of a MEMS piezoelectric generator, a voltage multiplication circuit and an energy storage unit. Supercapacitor has the potential to be an excellent power storage material for renewable energy sources. The interdigital structured supercapacitor consists of silicon as the substrate, nickel as current collectors and polyvinyl alcohol based gel as a solid state electrolyte. Coventorware ver. 2008 was used in this work to simulate the working structure of supercapacitor. Physical parameters such as length of fingers, electrode spacings, and electrode widths strongly influence the capacitance value of the interdigital structured supercapacitor. From the simulation, the maximum charge density value is 4.1×10^-6 pC/ μm² and the maximum capacitance achieved is 0.116pF for finger length of 2500 μm. The results presented here is crucial in obtaining an optimal design for interdigital structured supercapacitor to be used for powering biomedical devices.