High-Frequency Micro Supercapacitors Based on High-Aspect-Ratio 3D Nanoporous Gold Interdigital Electrodes for On-Chip Filtering

Micro supercapacitor (MSC) featured by high capacity and superior frequency response, is a great candidate to replace bulky electrolytic capacitors in circuits for miniaturization. This paper presents a novel high-aspect-ratio three-dimensional(3D) nanoporous gold (NPG) interdigital electrode with thickness as high as 8 μm. The thick electrodes render the micro device an unprecedented high capacitance of 1.64 mF/cm² for NPG based MSCs. Meanwhile, the electrodes remain excellent conductivity and porosity so that the MSC can efficiently operate at high frequency of 120 Hz or high charge/discharge rate of 500 V/s. Moreover, the on-chip device could be integrated and applied in a low-pass filtering circuit, showing great advantages compared with traditional electrolytic capacitors.