Self-powered Interface Circuit Research Articles

A Self-Powered Interface Circuit for Piezoelectric and Photovoltaic Energy Extracting

This paper presents a high-efficiency multi-source energy harvesting system consisting of a piezoelectric rectifier, a photovoltaic maximum power point tracking circuit and a fast self-startup circuit for powering wireless sensor nodes. Synchronous electric charge extraction techniques (SECE) are utilized to extract the piezoelectric energy when the deflection of piezoelectric energy harvester beam reaches its peak. Compared with other circuits, the proposed SECE technique can achieve piezoelectric and photovoltaic extraction simultaneously with a concise flyback topology structure. A novel maximum power point tracking method is adopted to enhance the robustness of operation against changing operating condition and improve the photovoltaic extraction efficiency. To remove the need for a battery, a simple and efficient self-startup circuit is introduced. The energy harvesting circuit is fabricated in 180 nm CMOS process. Measurement results show a fast self-startup at a relatively low light intensity of 120 lux is realized. The energy harvesting circuit is capable of outputting 189 μW power at 3.3 V piezoelectric open circuit voltage and 0.6 V photovoltaic input voltage.

A Dual-Output Rectifier-based Self-Powered Interface Circuit for Triboelectric Nanogenerators

A Dual-Output Rectifier-based Self-Powered Interface Circuit for Triboelectric Nanogenerators

A Self-Powered Interface Circuit for Simultaneous Piezoelectric and Electromagnetic Energy Extraction

A self-powered circuit for the combination of synchronized electric charge extraction (SECE) and synchronous magnetic flux extraction (SMFE) interfaces (SP-SECE-SMFE) is proposed, which can simultaneously extract energy from piezoelectric transducer (PZT) and electromagnetic transducer (EMT). It reveals that when the energy extraction time of PZT and EMT is consistent, the electromagnetic energy harvested by SP-SECE-SMFE is greatly improved due to the action of the pulse piezoelectric voltage, and demonstrates how to use a resistance to adjust the energy extraction time of PZT. Simulation results show that the output power of SP-SECE-SMFE for the hybrid harvesting of piezoelectric and electromagnetic energy is 1.4-2.4 times higher than that of the sum when they are harvested separately under different frequencies and loads. Experimental results show that the maximum output power achieved by SP-SECE-SMFE is 1.7 times higher than that of the sum when are they harvested by the self-powered circuits of SECE and SMFE respectively, and is 2.2 times higher than that of the half-bridge rectifier circuit. The simulation and experimental results show the superiority of the proposed SP-SECE-SMFE circuit.

A graded metamaterial for broadband and high-capability piezoelectric energy harvesting

This work proposes a graded metamaterial-based energy harvester integrating the piezoelectric energy harvesting function targeting low-frequency ambient vibrations (<100 Hz). The harvester combines a graded metamaterial with beam-like resonators, piezoelectric patches, and a self-powered interface circuit for broadband and high-capability energy harvesting. Firstly, an integrated lumped parameter model is derived from both the mechanical and the electrical sides to determine the power performance of the proposed design. Secondly, thorough numerical simulations are carried out to optimize both the grading profile and wave field amplification, as well as to highlight the effects of spatial-frequency separation and the slow-wave phenomenon on energy harvesting performance and efficiency. Finally, experiments with realistic vibration sources validate the theoretical and numerical results from the mechanical and electrical sides. Particularly, the harvested power of the proposed design yields a five-fold increase with respect to conventional harvesting solutions based on single cantilever harvesters. Our results reveal that by bridging the advantages of graded metamaterials with the design targets of piezoelectric energy harvesting, the proposed design shows significant potential for realizing self-powered Internet of Things devices.

Efficient self-powered piezoelectric energy harvesting interface circuit with wide rectified voltage

Synchronized Switching Harvesting on Inductor (SSHI) and Synchronous Electric Charge Extraction (SECE) are two classic interface circuit techniques for Piezoelectric energy harvesting. But the former has high peak output power with narrow rectified voltage range, while the latter has wide rectified voltage range with lower peak output power. This paper presents a self-powered interface circuit for piezoelectric energy harvesting to achieve a good balance between the two. The proposed interface circuit is based on the Series-SSHI (S–SSHI) and SECE. The circuit proposed can harvest energy through S–SSHI and SECE in positive and negative half cycles, respectively. Moreover, the figure of merit (FOM), optimal rectified voltage range (ORVR) and region of interest (SRoI) of simulation and experiment results are discussed. The maximum FOM of the proposed circuit is as high as 2.15, which is 1.68 times that of the SECE, and it can reach 6 times the ORVR of the S–SSHI. SRoI factor of the proposed circuit show that the proposed method has better performance. In addition, the circuit shows a simpler implementation compared with state-of-the-art designs.

An Autonomous Interface Circuit Based on Self-Investing Synchronous Energy Extraction for Low Power Piezoelectric Energy Harvesters

This paper presents a self-powered interface circuit to rectify and manage the AC output of the piezoelectric energy harvesters (PEH) by utilizing Self-Investing Synchronous Electric Charge Extraction technique (SI-SECE). The system invests charges from the battery to PEH to improve the electromechanical coupling factor and consequently the energy extraction by utilizing only one external component. The circuit was implemented in 180 nm CMOS technology where high voltage (HV) MOS transistors are utilized to tolerate high open circuit output voltages of PEHs. MEMS PEH with 4.7 nF inherent capacitance has been used to charge a 1 μF storage capacitor. Proposed interface circuit extracts 18.55 μW that is 33 % more than traditional SECE (13.95 μW) for 250 Hz PEH excitation frequency and 2.3 V piezoelectric open circuit voltage amplitude. At the output power of 48.5 μW, maximum power conversion efficiency of 62.4% is achieved as charge investment and corresponding conduction and switching losses on investing transistors. SI-SECE delivers power with 4.5x relative performance improvement over on-chip full-bridge rectifier.

An Adaptable Interface Circuit With Multistage Energy Extraction for Low-Power Piezoelectric Energy Harvesting MEMS

This paper presents a self-powered interface circuit to extract energy from ambient vibrations for powering up microelectronic devices. The circuit interfaces a piezoelectric energy harvesting micro electro-mechanical systems (MEMS) device to scavenge acoustic energy. Synchronous electric charge extraction (SECE) technique is deployed through the implementation of a novel multistage energy extraction (MSEE) circuit in 180 nm HV CMOS technology to harvest and store energy. The circuit is optimized to operate with minimum power losses when input power is limited, and adapts well to operating conditions with higher input power. The highly accurate peak detector was validated for a wide piezoelectric frequency range from 20 Hz to 4 kHz. A charging efficiency of about 84% has been achieved for 4.75 V open-circuit piezoelectric voltage excited at 390 Hz input vibration under nominal input power range of 30–80 μW. Power optimizations enable the circuit to maintain a conversion efficiency of 47% at input power level as low as 3.12 μW. MSEE provides up to 15% efficiency improvement compared to traditional SECE, and maintains power efficiency as high as possible for a wide input power range.

Self-powered optimized synchronous electric charge extraction circuit for piezoelectric energy harvesting

This article presents a self-powered interface circuit for the optimized synchronous electric charge extraction technique applied to piezoelectric vibration energy harvesting. A peak detector circuit is developed to detect the maximum and minimum vibration displacements and drive the electronic switches synchronously. This approach does not require additional piezoelectric elements to power the electronic interface itself for which a detailed analysis and a simple model are proposed to give a better understanding on the working principle. Finally, the influence of the switching phase lag and the peak detector power consumption on the harvested power is studied. Experimental studies are conducted and successfully compared with the theoretical approach.