Impact induced compound method for triboelectric-piezoelectric hybrid nanogenerators to achieve Watt level average power in low frequency rotations

Abstract Achieving hybrid nanogenerator is an important device technique to multiplex working mode and increase power generation capability of traditional triboelectric nanogenerators (TENGs). Typically, TENGs are characterized by pulsed output with voltage spikes on level of tens or hundreds of volts, which raises challenges such as low average power and voltage surge risks for electronic systems in most industrial applications. To solve this problem, this paper presents an impact induced compound method to achieve triboelectric and piezoelectric hybrid nanogenerator, in which impacts first induce frictions to generate triboelectric power, and then induce beam deflections to prompt the self-oscillation and generate piezoelectric power. Based on this method, a hybrid device has been designed to achieve Watt level average power in low frequency rotations (≤9.38Hz). Device parameters such as beam thickness, overlap length and contact angle have been experimentally optimized. Results show that under diverse testing conditions, the hybrid nanogenerator produces steady voltage waveforms both during and after friction, which is the key factor to boost average power. With only 1 rotor and 1 stator, the hybrid nanogenerator is able to lighten 150 light emitting diodes and to power a 12-digit electronic calculator. The average power of the hybrid nanogenerator can be further improved through multiplying rotors and stators. With 3 rotors and 4 stators, rectified voltage in the range of 12.1-51.6V has been achieved, and average power of 1.04W is obtained on 511Ω load resistor.