A conditioning circuit with exponential enhancement of output energy for triboelectric nanogenerator

Triboelectric-electret nanogenerators (T-ENG) are characterized by their high output voltage and small current and therefore a relatively low output power, making them limited to small power consuming electronics. Here we report a self-enhancing conditioning circuit (CC) that exponentially amplifies the output electrical energy converted from the mechanical domain of a T-ENG, in orders of magnitude compared to traditional CC. The circuit, working on the principles of Bennet's doubler device, is inductorless and uses only diodes as automatic switches to reconfigure the charge storing capacitors between series and parallel modes. We previously reported this circuit in saturation and stable mode for T-ENG and compared the performances with half-wave rectifier. Here we investigate the circuit performance in exponential and unstable mode in comparison with half-wave and full-wave rectifiers. Theoretical analysis is presented to study the operation of the circuit and to find out the required conditions for the Bennet's doubler to work in exponential boosting mode. Output performance of half and full wave rectifiers are compared theoretically. Simulations and experiments are performed to verify the theoretical discussions and to present the effect of non-ideal circuit elements on the output performance of the T-ENG.