A nanogenerator includes a first frame, a second frame, a first conductor, a second conductor, an array of nano-rods, and an array of electrodes. The second frame engages the first frame. The first conductor is fixed to a first inner surface of the first frame facing the second frame. The second conductor is fixed to a second inner surface of the second frame facing the first frame. The array of nano-rods extends from a first surface of the first conductor toward the second frame. The array of electrodes extends from a second surface of the second conductor toward the first frame. The array of electrodes corresponds to the array of nano-rods. The hardness of the array of electrodes is being greater than that of the array of nano-rods.