Self-powered Piezoelectric Energy Harvesting Research Articles

Self-powered piezoelectric energy harvesting with ultra-low power consumption for low-amplitude ambient vibrations

Self-powered piezoelectric energy harvesting with ultra-low power consumption for low-amplitude ambient vibrations

Simulation and performance analysis of self-powered piezoelectric energy harvesting system for low power applications

<span lang="EN-US">Energy harvesting is a process of extracting energy from surrounding environments. The extracted energy is stored in the supply power for various applications like wearable, wireless sensor, and internet of thing (IoT) applications. The electricity generation using conventional approaches is very costly and causes more pollution in the environmental surroundings. In this manuscript, an energy-efficient, self-powered battery-less piezoelectric-based energy harvester (PE-EH) system is modeled using maximum power point tracking (MPPT) module. The MPPT is used to track the optimal voltage generated by the piezoelectric (PE) sensor and stored across the capacitor. The proposed PE system is self-operated without additional microarchitecture to harvest the Power. The experimental simulation results for the overall PE-EH systems are analyzed for different frequency ranges with variable input source vibrations. The optimal voltage storage across the storing capacitor varies from 1.12 to 1.6 V. The PE-EH system can harvest power up to 86 µW without using any voltage source and is suitable for low-power applications. The proposed PE-EH module is compared with the existing similar EH system with better improvement in harvested power.</span>

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.

A Self-Powered Piezoelectric Energy Harvesting Circuit With an Optimal Flipping Time SSHI and Maximum Power Point Tracking

This brief presents an ultra low power IC design for piezoelectric (PE) energy harvesting, which integrates a maximum power point tracking (MPPT) circuit and a synchronized switch harvesting on inductor (SSHI) circuit. The proposed circuit also has three different operation modes to extend the range of the harvestable power level generated by a PE transducer. The circuit is designed in CMOS and fabricated in BiCMOS 0.25 $\mu \text{m}$ technology with the die size of 2 mm2. The measurement results indicate the circuit can harvest energy with the input power ranging from 10 to 34 $\mu \text{W}$ during MPPT. It achieves peak efficiency of 77% under a PE cantilever voltage of 3.5 V and the battery voltage of 4.2 V.

A self-powered piezoelectric energy harvesting interface circuit with efficiency-enhanced P-SSHI rectifier * * Project supported by the National Natural Science Foundation of China (Nos. 61574103, U1709218) and the Key Research and Development Program of Shaanxi Province (No. 2017ZDXM-GY-006).

The key to self-powered technique is initiative to harvest energy from the surrounding environment. Harvesting energy from an ambient vibration source utilizing piezoelectrics emerged as a popular method. Efficient interface circuits become the main limitations of existing energy harvesting techniques. In this paper, an interface circuit for piezoelectric energy harvesting is presented. An active full bridge rectifier is adopted to improve the power efficiency by reducing the conduction loss on the rectifying path. A parallel synchronized switch harvesting on inductor (P-SSHI) technique is used to improve the power extraction capability from piezoelectric harvester, thereby trying to reach the theoretical maximum output power. An intermittent power management unit (IPMU) and an output capacitor-less low drop regulator (LDO) are also introduced. Active diodes (AD) instead of traditional passive ones are used to reduce the voltage loss over the rectifier, which results in a good power efficiency. The IPMU with hysteresis comparator ensures the interface circuit has a large transient output power by limiting the output voltage ranges from 2.2 to 2 V. The design is fabricated in a SMIC 0.18 μm CMOS technology. Simulation results show that the flipping efficiency of the P-SSHI circuit is over 80% with an off-chip inductor value of 820 μH. The output power the proposed rectifier can obtain is 44.4 μW, which is 6.7× improvement compared to the maximum output power of a traditional rectifier. Both the active diodes and the P-SSHI help to improve the output power of the proposed rectifier. LDO outputs a voltage of 1.8 V with the maximum 90% power efficiency. The proposed P-SSHI rectifier interface circuit can be self-powered without the need for additional power supply.

A Power-Enhanced Active Rectifier with Offset-Controlled Comparator for Self-Powered PEH Systems

In this paper, a power-enhanced active rectifier with high precision of current detection for piezoelectric energy harvesting (PEH) system is presented. A traditional two-stage active rectifier is adopted, which includes a first-stage negative voltage converter and an active diode. A comparator with offset control technique is proposed; thus the input-referred offset voltage of the proposed comparator can be less than 1[Formula: see text]mV. The current detected accuracy of the proposed offset-controlled comparator (OCC) is improved by more than 10 times over a traditional comparator. Output oscillations of the OCC are dramatically reduced attributing to the high precision of current detection. In addition, the OCC is also able to prevent the reverse leakage current. The design is implemented in an SMIC 0.18[Formula: see text][Formula: see text]m standard CMOS technology with a chip area of 0.22[Formula: see text]mm2. The measurement results show that the maximum output power, power conversion efficiency and figure of merit are 23.3[Formula: see text][Formula: see text]W, 90%, and 0.9, respectively, when the open-circuit voltage is 2.4[Formula: see text]V. The proposed rectifier can be self-powered without the additional external supply.

An Efficient Self-Powered Piezoelectric Energy Harvesting CMOS Interface Circuit Based on Synchronous Charge Extraction Technique

An efficient self-powered synchronous electric charge extraction CMOS interface circuit dedicated to piezoelectric harvesters is proposed in this paper. Self-powered peak detection (PKD) and switch circuits are used to reduce quiescent current so that the backup or pre-charged power can be saved. A new low phase lag (LPL) PKD circuit is designed to improve the synchronous extraction efficiency, which only requires one detection capacitor to perform positive and negative PKD. The circuit can be set at general mode (G-mode) or LPL mode (LPL-mode). Under LPL-mode, the phase lag can be reduced typically by 50%, the synchronous extraction efficiency can obtained up to 94%, while the output power can reach 659 μW when the piezoelectric transducer original opencircuit voltage Voc,org = 5 V, which is 3.56 times of that of full-bridge rectifier standard energy harvesting circuit at the maximum power point. The minimum harvesting startup voltage is 1.7 V and is independent of the energy storage capacitor voltage VDC. The harvesting efficiency can still reach 71.3% at Voc,org = 5 V. The size of the active area is 0.5 mm2 in a 0.18-μm CMOS technology. Circuit may be invoked as a functional block for energy autonomous wireless sensor network node of the Internet of Things.

A Self-Powered Piezoelectric Energy Harvesting Interface with Wide Input Range in 65 nm CMOS Process

ABSTRACTA self-powered piezoelectric energy harvesting interface circuit (PEHIC) with wide input range and good performance is presented in this paper. The proposed PEHIC consists of a two-stage active charge pump rectifier and an ultra-low power intermittent power management unit (IPMU). Active diodes based on unbalanced-biased comparators improve the reverse leakage current problem that conventional active diodes faced. By limiting the output voltage between 1.2 and 0.8 V, the IPMU working in intermittent mode can provide an expanded input range and ensure that the interface circuit has a large transient output power. Implemented in a 65 nm standard complementary metal oxide semiconductor (CMOS) technology, the PEHIC has been simulated and verified. Simulation results show that an AC signal with amplitude ranging from 0.32 to 1.5 V and frequencies of 20 Hz–3 kHz can be rectified. The maximum output current is as large as 5 mA. The peak power conversion efficiency is up to 81% when the input voltage is 0.8 V at 200 Hz. The PEHIC can be self-powered without the need for additional power supply.

Low-Power Design of a Self-powered Piezoelectric Energy Harvesting System With Maximum Power Point Tracking

A low-power energy harvesting system targeting to harvest several milliwatts from vibration is presented in this paper. Several low-power design schemes to reduce power dissipation of the proposed system are described, and sources of power loss are analyzed to improve the power efficiency. A discontinuous conduction mode (DCM) flyback converter with the constant on-time modulation is adopted for our system. The DCM operation of a flyback converter is chosen as for maximum power point tracking (MPPT) to be implemented with a single current sensor. The constant on-time modulation lowers the clock frequency of the controller by more than an order of magnitude for our system, which reduces the dynamic power dissipation of the controller. MPPT, executed by a microcontroller unit (MCU), is achieved through dynamic resistive matching, and the MPPT is executed at intermittent time intervals due to a relatively slow change of the operating condition. When MPPT is not active, the MCU operates at a lower clock frequency to save power. Experimental results indicate that the proposed system harvests up to 8.4 mW power under 0.5-g base acceleration with four parallel piezoelectric cantilevers and achieves 72% power efficiency around the resonant frequency of 47 Hz.

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.