Self-powered Switching Research Articles

A Self-Powered Dual-Type Signal Vector Sensor for Smart Robotics and Automatic Vehicles.

Automatic control systems are the most efficient technology for reducing labor cost while improving work efficiency. Vector motion monitoring is indispensable for the normal operation of automatic control systems. Here, a self-powered dual-type signal triboelectric nanogenerator (DS-TENG) is designed through integrating an alternating-current TENG and a direct-current TENG, which can monitor vector movement in real time based on pulse signal counts. As a result, the DS-TENG avoids the shortcoming of traditional self-powered sensors based on signal amplitude that is sensitive to the working environment, achieves a high sensing precision, and maintains stability after reciprocating motion of 500000 cycles. Moreover, it realizes effective movement direction recognition by self-powered switching of signal type in reverse movement. This dual-type signal TENG exhibits high precision and automatic direction recognition in vector motion monitor and trajectory tracker, paving the way for the application of the self-powered TENG sensor in automatic control systems in the future.

Compact self-powered synchronous energy extraction circuit design with enhanced performance

Synchronous switching circuit is viewed as an effective solution of enhancing the generator’s performance and providing better adaptability for load variations. A critical issue for these synchronous switching circuits is the self-powered realization. In contrast with other methods, the electronic breaker possesses the advantage of simplicity and reliability. However, beside the energy consumption of the electronic breakers, the parasitic capacitance decreases the available piezoelectric voltage. In this technical note, a new compact design of the self-powered switching circuit using electronic breaker is proposed. The envelope diodes are excluded and only a single envelope capacitor is used. The parasitic capacitance is reduced to half with boosted performance while the components are reduced with cost saved.

Deep blue energy harvest photovoltaic switching by heptazole-based organic Schottky diode circuits

We report novel photovoltaic (PV) switching based on the low exciton-binding energy property of an organic heptazole (C26H16N2) thin film after fabrication of an heptazole-based Schottky diode. The Schottky diode cell displayed an instantaneous voltage of 0.3 V as an open circuit voltage (VOC) owing to the work function difference between the Schottky and ohmic electrode under deep blue illumination. Four tandem diode cells therefore produced ~1.2 V. As a PV diode circuit can be formed using an even number of diodes, a photo-excited charge accumulation takes place, generating VOC in the central electrode of the tandem diode array by illuminating one half of the array. An electron–hole recombination then also takes place in that electrode by illuminating the other half, making the VOC decrease to 0 V. Utilizing this charge accumulation and recombination under deep blue illumination, we successfully demonstrated quite fast PV optical switching, logic gating and, ultimately, the gate switching of an organic field-effect transistor. We therefore concluded that our self-powered PV-induced switching was novel and promising enough to open a new door for energy harvest-related device applications in organics. Photovoltaic switching in organic thin films has been realized by a team in Korea. The photovoltaic effect is virtually synonymous with light harvesting using solar-cell technology, but researchers have now demonstrated another application of it — self-powered switching. Seongil Im of Yonsei University in Seoul and co-workers made Schottky diode cells that exploit the low exciton-binding energy of thin films made from heptazole (C26H16N2). Under deep-blue illumination, the cells generated a voltage of 0.3 volts. Furthermore, they exhibited relatively fast photovoltaic switching, logic gating and gate switching of an organic field-effect transistor. The team anticipates that this self-powered switching could be used for detection of ultraviolet and visible light, wireless healthcare devices and powerless communication. It is especially suited for devices designed to protect the eyes from ultraviolet light. Photovoltaic switching in organic heptazole Schottky diode circuits is successfully implemented under dynamic illumination. Blue energetic photons generate electron–hole pairs, and instantaneous voltage of 0.3 V is produced that is multiplied by tandem diode structure. Using the photovoltaic effects, NOT, OR and AND logics are demonstrated without any electric power.

Applied self-powered semi-passive control for a 2-degree-of-freedom aeroelastic typical section using shunted piezoelectric materials

The use of smart materials in vibration control problems, including aeroelastic response, has been investigated in several researches over the last years. Although different smart materials are available, the piezoelectric one has received great attention due to ease of use as sensors, actuators, or both. The main control techniques using piezoelectric materials are the active and passive ones. In the case of aeroelastic control, passive piezoelectric networks have a weak capability of improving the flutter stability margin. Although active systems can achieve good vibration control performance, the amount of external power and added hardware are important issues for active aeroelastic control. In this article, the self-powered semi-passive piezoelectric control of a wind tunnel model aeroelastic response is presented as an alternative to active and passive systems. Linear and nonlinear aeroelastic cases are examined using a test apparatus that allows for experiments of pitch and plunge degrees of freedom of a typical section. Piezoelectric coupling is introduced onto the plunge degree of freedom, and two different semi-passive control schemes are employed: the synchronized switch damping on short circuit and the synchronized switch damping on inductor. An autonomous and self-powered switching circuit is employed, providing a useful self-powered method of aeroelastic control.

Theoretical analyses of the electronic breaker switching method for nonlinear energy harvesting interfaces

It has been proved that the harvested energy can be greatly improved by applying nonlinear treatments on the piezoelectric element. These treatments consist of switching the piezoelectric element on a resonant electrical network intermittently. To implement these treatments with little power consumption, a self-powered switching circuit called electronic breaker has been researched. Although the operation of the switching control circuit has been introduced, the theoretical model of the circuit has not been set up. Therefore, the purpose of this article is to further investigate the mechanism of this circuit and to establish its theoretical model. Furthermore, this switching circuit is employed in the parallel synchronized switch harvesting on inductor interface and the synchronous charge extraction interface. It is proved that the electronic breaker can fulfill different switching times in these interfaces. It is shown both theoretically and experimentally that the parallel synchronized switch harvesting on inductor interface allows a gain of 18.4 of power compared to a standard circuit, while the synchronous charge extraction interface results in a gain of 4. Meanwhile, the switching circuits consume less than 2% power of that harvested. Thus, the electronic breaker circuit has been proved an efficient way of charging control for self-powered vibration generators.

A self-powered switching circuit for piezoelectric energy harvesting with velocity control

The rapid development of low-power consumption electronics and the possibility of harvesting energy from environmental sources can make totally autonomous wireless devices. Using piezoelectric materials to convert the mechanical energy into electrical energy for batteries of wireless devices in order to extend the lifetime is the focus in many researches in the recent years. It is important and efficient to improve the energy harvesting by designing an optimal interface between piezoelectric device and the load. In this paper, a self-powered piezoelectric energy harvesting device is proposed based on the velocity control synchronized switching harvesting on inductor technique (V–SSHI). Comparing to the standard full bridge rectifier technique, the synchronized switching harvesting on inductor (SSHI) technique can highly improve harvesting efficiency. However, in real applications when the energy harvesting device is associated with wireless sensor network (WSN), the SSHI technique needs to be implemented and requires being self-powered. The conventional technique to implement self-powered SSHI is to use bipolar transistors as voltage peak detector. In this paper, a new self-powered device is proposed, using velocity control to switch the MOSFET more accurately than in the conventional technique. The concept of design and the theoretical analysis are presented in detail. Experimental results are examined.

An optimized self-powered switching circuit for non-linear energy harvesting with lowvoltage output

Harvesting energy from environmental sources has been of particular interest these last fewyears. Microgenerators that can power electronic systems are a solution for the conceptionof autonomous, wireless devices. They allow the removal of bulky and costly wiring,as well as complex maintenance and environmental issues for battery-poweredsystems. In particular, using piezoelectric generators for converting vibrationalenergy to electrical energy is an intensively investigated field. In this domain,it has been shown that the harvested energy can be greatly improved by theuse of an original non-linear treatment of the piezoelectric voltage called SSHI(Synchronized Switch Harvesting on Inductor), which consists in intermittently switchingthe piezoelectric element on a resonant electrical network for a very short time.However, the integration of miniaturized microgenerators with low voltage output(e.g. MEMS microgenerators) has not been widely studied. In the case of lowvoltage output, the losses introduced by voltage gaps of discrete components suchas diodes or transistors can no longer be neglected. Therefore the purpose ofthis paper is to propose a model that takes into account such losses as well as anew architecture for the SSHI energy harvesting circuit that limits such lossesin the harvesting process. While most of the study uses an externally poweredmicrocontroller for the non-linear treatment, this circuit is fully self-powered, thusproviding an enhanced autonomous microgenerator. In particular this circuitaims at limiting the effect of non-linear components with a voltage gap such asdiodes. It is shown both theoretically and experimentally that the harvested powercan be significantly increased using such a circuit. In particular, experimentalmeasurements performed on a cantilever beam show that the circuit allows a160% increase of the harvested power compared to a standard energy harvestingcircuit, while the classical implementation of the SSHI shows an increase of only100% of the output power in the classical case.