In this Letter, the authors introduce for the first time how a Bennet's doubler conditioning circuit will boost the extracted energy from an electrostatic kinetic energy harvester based on ...triboelectricity. With zero initial bias on all capacitors, after 1000 charging cycles, the harvested power is amplified by more than 2 orders of magnitude by the Bennet's doubler in comparison to a half-wave diode bridge. The harvested energy derived from a 3 × 3 cm2 device made of polymer PFA and aluminium is at least 4.6 μJ per tap with the Bennet's doubler conditioning circuit, and only 30 nJ per tap with the half-wave bridge.
We present for the first time how a Bennet's doubler conditioning circuit can boost the electrical energy extracted from an electrostatic Kinetic Energy Harvester (e-KEH) based on triboelectricity, ...commonly called Tribo-Electric Nano-Generator (TENG). After 1000 charging cycles, the harvested power is increased by more than 2 orders of magnitude with the Bennet doubler compared to a half-wave diode bridge. The maximum energy extracted by a 3×3 cm2 device made of PFA and aluminum is no less than 4.6 μJ per tap through the Bennet's doubler circuit.
This paper reports for the first time a MEMS electrostatic vibration energy harvester (e-VEH) with corona-charged vertical electrets on its electrodes. The bandwidth of the 1-cm2 device is extended ...in low and high frequencies by nonlinear elastic stoppers. With a bias voltage of 46 V (electret@21 V + DC external source@25 V) between the electrodes, the RMS power of the device reaches 0.89 μW at 33 Hz and 6.6 μW at 428 Hz. The -3dB frequency band including the hysteresis is 223∼432 Hz, the one excluding the hysteresis 88∼166 Hz. We also demonstrate the charging of a 47 μF capacitor used for powering a wireless and autonomous temperature sensor node with a data transmission beyond 10 m at 868 MHz.
The paper is devoted to a novel study of monophase MEMS electrostatic Vibration Energy Harvester (e-VEH) with conditioning circuit based on Bennet's doubler. Unlike the majority of conditioning ...circuits that charge a power supply, the circuit based on Bennet's doubler is characterized by the absence of switches requiring additional control electronics, and is free from hardly compatible with batch fabrication process inductive elements. Our experiment with a 0.042 cm3 batch fabricated MEMS e-VEH shows that a pre-charged capacitor as a power supply causes a voltage increase, followed by a saturation which was not reported before. This saturation is due to the nonlinear dynamics of the system and the electromechanical damping that is typical for MEMS. It has been found that because of that coupled behavior there exists an optimal power supply voltage at which output power is maximum. At 187 Hz / 4 g external vibrations the system is shown to charge a 12 V supply with a output power of 1.8 μW.
This paper reports on an electrostatic Vibration Energy Harvester (e-VEH) system, for which the energy conversion process is initiated with a low bias voltage and is compatible with wideband ...stochastic external vibrations. The system employs the auto-synchronous conditioning circuit topology with the use of a novel dedicated integrated low-power high-voltage switch that is needed to connect the charge pump and flyback – two main parts of the used conditioning circuit. The proposed switch is designed and implemented in AMS035HV CMOS technology. Thanks to the proposed switch device, which is driven with a low-voltage ground-referenced logic, the e-VEH system may operate within a large voltage range, from a pre-charge low voltage up to several tens volts. With such a high-voltage e-VEH operation, it is possible to obtain a strong mechanical coupling and a high rate of vibration energy conversion. The used transducer/resonator device is fabricated with a batch-processed MEMS technology. When excited with stochastic vibrations having an acceleration level of 0.8 g rms distributed in the band 110–170 Hz, up to 0.75 μW of net electrical power has been harvested with our system. This work presents an important milestone in the challenge of designing a fully integrated smart conditioning interface for the capacitive e-VEHs.
This letter deals with an innovative design for a silicon MEMS DC/DC converter, to be used in autonomous mechanical-energy scavengers, based on electrostatic transduction. The device is made of bulk ...silicon and is fabricated using a batch process. It is 27 mm 3 in volume and resonates at 250 Hz. We demonstrate a net vibration-to-electricity power conversion of between 60 and 100 nW in autonomous mode, i.e., without injecting and introducing new charges from an external power supply. We have compared the measurements with the results of a mixed VHDL-AMS/ELDO modeling experiment, and the agreement between these two experiments is better than 3%.
This paper reports the application of different analytical tools to a basic continuous conditioning (CC) circuit for electrostatic vibration energy harvesters (e-VEHs). We address the fundamental ...issues of this conditioning circuit and give design advice that enhances the performance of e-VEHs employing this circuit. This circuit is widely used for harvesters with or without an electret layer. Despite its wide use, its fundamental problems have been weakly addressed even for simple configurations of e-VEHs since it is impossible to solve the corresponding equations in closed form. As a consequence, appropriate semi-analytical methods that provide an insight into the physics of the system are required.
We present a new concept for impact-based triboelectric nanogenerators (TENG) inspired from the electrostatic machines of the 18th century. With this system, the electrical energy converted from the ...mechanical domain is automatically accumulated in a large capacitance without the need of diodes. Our TENG has three electrodes and self-synchronized/self-actuated mechanical switches, which automatically and repeatedly connect the capacitances of the system according to their series and parallel configurations in order to reproduce a behaviour similar to the Bennet's charge doubler. The movable and freestanding electrode is covered with triboelectric patches that drastically decreases the start-up time. The output voltage, and so the harvested energy, increases exponentially until either the output voltage reaches the air dielectric breakdown or a saturation occurs because the electrostatic forces become comparable to the mechanical ones. We have developed a complete numerical model that takes into account both electrical and mechanical forces and is able to show the saturation phenomena due to the high electromechanical coupling occurring at high voltage. This model has been validated with practical experiments where the prototype were excited with a sinusoidal acceleration of 0.2 grms at 5 Hz. This new and diode-free concept can be applied to any TENG having at least one variable capacitor to boost the mechanical-to-electrical energy conversion.
We report a new type of triboelectric nanogenerator (TENG) having alternating and self-actuated series-to-parallel interfaces based on self-synchronized mechanical switches. It has been inspired from the Bennet doubler electrical machine. The TENG is composed of a freestanding electrode, two anti-phase variable capacitors excited by the external vibrations, and a reservoir capacitor. The absence of diodes and their unavoidable voltage threshold for signal rectification, combined with the boost introduced by the Bennet-like doubler structure, can largely improve the energy conversion efficiency of TENGs, especially during the start-up. Display omitted
•We report a new TENG having a self-actuated series-to-parallel electrical interface based on mechanical switches.•The absence of diodes combined with the Bennet-like doubler can largely improve the energy conversion efficiency of TENGs.•A numerical model that takes into account both electrical and mechanical forces has been validated with the experiments.
In this paper, we present a formal analysis and description of the steady-state behavior of an electrostatic vibration energy harvester operating in constant-charge mode and using different types of ...electromechanical transducers. The method predicts parameter values required to start oscillations, allows a study of the dynamics of the transient process, and provides a rigorous description of the system, necessary for further investigation of the related nonlinear phenomena and for the optimisation of converted power. We show how the system can be presented as a nonlinear oscillator and be analysed by the multiple scales method, a type of perturbation technique. We analyse two the most common cases of the transducer geometry and find the amplitude and the phase of steady-state oscillations as functions of parameters. The analytical predictions are shown to be in good agreement with the results obtained by behavioral modeling.
PDF
