PLANAR MEMS SUPERCAPACITOR USING CARBON NANOTUBE FORESTS

Planar micro supercapacitors utilizing vertically aligned carbon nanotube (CNT) forests with the design of interdigital electrodes have been demonstrated. Conductive substrates using Mo/Al/Fe metal stack shows best CNT forest synthesis results with high electrical conductivity and dense CNT structures. Prototype devices show measured specific capacitances about 1000 times higher than those with plain metal electrodes without CNT forests. Furthermore, charging/discharging experiments show over 92% efficiency and very robust cycling stability. As such, we believe these planar MEMS supercapacitors could be applicable in various systems including energy harvesters, pulse-power supplies and advanced microelectronics as on-chip capacitors.