The triboelectric nanogenerator (TENG) is a newly invented technology that is effective for harvesting ambient mechanical energy for portable electronics, self-powered sensor networks, etc. Here, by introducing segmentation and multilayer integration into the cylindrical TENG, the generator's output is enhanced significantly. With a four-layer and thirty-segment configuration, the TENG produces a short-circuit current of 86 A (13.5 A m(-2)) and power of 4.3 mW (676 mW m(-2)) at a rotating speed of 600 rpm, which are respectively over 70 and 15 times higher than those of the one-layer and one-segment structure. This makes the TENG a sufficient power supply for conventional electronics, such as light bulbs and temperature sensors. Furthermore, it is demonstrated that the segmentation design is a perfect self-power management technique to automatically lower the TENG's output voltage and increase its output current without scarifying the output power. The fractal geometry is an effective way to maximize the TENG's contact surface area and thereby the output performance.