scholarly journals Multieffect Coupled Nanogenerators

Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-24
Author(s):  
Yun Ji ◽  
Yuan Liu ◽  
Ya Yang

With the advent of diverse electronics, the available energy may be light, thermal, and mechanical energies. Multieffect coupled nanogenerators (NGs) exhibit strong ability to harvest ambient energy by integrating various effects comprising piezoelectricity, pyroelectricity, thermoelectricity, optoelectricity, and triboelectricity into a standalone device. Interaction of multitype effects can promote energy harvesting and conversion by modulating charge carriers’ behaviour. Multieffect coupled NGs stand for a vital group of energy harvesters, supporting the advances of an electronic device and promoting the resolution of energy crisis. The matchless versatility and high reliability of multieffect coupled NGs make them main candidates for integration in complicated arrays of the electronic device. Multieffect coupled NGs can also be employed as a variety of self-powered sensors due to their rapid response, high accuracy, and high responsivity. This article reviews the latest achievements of multieffect coupled NGs. Fundamentals mainly including basic theory and materials of interest are covered. Advanced device design and output characteristics are introduced. Potential applications are described, and future development is discussed.

Author(s):  
Guangya Ding ◽  
Hongjun Luo ◽  
Jun Wang ◽  
Guohui Yuan

A novel lever piezoelectric energy harvester (LPEH) was designed for installation in an actual roadway for energy harvesting. The model incorporates a lever module that amplifies the applied traffic load and transmits it to the piezoelectric ceramic. To observe the piezoelectric growth benefits of the optimized LPEH structure, the output characteristics and durability of two energy harvesters, the LPEH and a piezoelectric energy harvester (PEH) without a lever, were measured and compared by carrying out piezoelectric performance tests and traffic model experiments. Under the same loading condition, the open circuit voltages of the LPEH and PEH were 20.6 and 11.7 V, respectively, which represents a 76% voltage increase for the LPEH compared to the PEH. The output power of the LPEH was 21.51 mW at the optimal load, which was three times higher than that of the PEH (7.45 mW). The output power was linearly dependent on frequency and load, implying the potential application of the module as a self-powered speed sensor. When tested during 300,000 loading cycles, the LPEH still exhibited stable structural performance and durability.


2021 ◽  
Vol 11 (12) ◽  
pp. 5474
Author(s):  
Tuomo Poutanen

This article addresses the process to optimally select safety factors and characteristic values for the Eurocodes. Five amendments to the present codes are proposed: (1) The load factors are fixed, γG = γQ, by making the characteristic load of the variable load changeable, it simplifies the codes and lessens the calculation work. (2) Currently, the characteristic load of the variable load is the same for all variable loads. It creates excess safety and material waste for the variable loads with low variation. This deficiency can be avoided by applying the same amendment as above. (3) Various materials fit with different accuracy in the reliability model. This article explains two options to reduce this difficulty. (4) A method to avoid rounding errors in the safety factors is explained. (5) The current safety factors are usually set by minimizing the reliability indexes regarding the target when the obtained codes include considerable safe and unsafe design cases with the variability ratio (high reliability/low) of about 1.4. The proposed three code models match the target β50 = 3.2 with high accuracy, no unsafe design cases and insignificant safe design cases with the variability ratio 1.07, 1.03 and 1.04.


Author(s):  
Jie Chen ◽  
Yifei Wang ◽  
Weixing Chen

Multilayer composites have the potential applications in organic film capacitors due to their excellent dielectric and breakdown characteristic. However, poor efficiency (η) and limited available energy density (Ue) of the...


Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 803
Author(s):  
Zhongjie Li ◽  
Chuanfu Xin ◽  
Yan Peng ◽  
Min Wang ◽  
Jun Luo ◽  
...  

A novel hybridization scheme is proposed with electromagnetic transduction to improve the power density of piezoelectric energy harvester (PEH) in this paper. Based on the basic cantilever piezoelectric energy harvester (BC-PEH) composed of a mass block, a piezoelectric patch, and a cantilever beam, we replaced the mass block by a magnet array and added a coil array to form the hybrid energy harvester. To enhance the output power of the electromagnetic energy harvester (EMEH), we utilized an alternating magnet array. Then, to compare the power density of the hybrid harvester and BC-PEH, the experiments of output power were conducted. According to the experimental results, the power densities of the hybrid harvester and BC-PEH are, respectively, 3.53 mW/cm3 and 5.14 μW/cm3 under the conditions of 18.6 Hz and 0.3 g. Therefore, the power density of the hybrid harvester is 686 times as high as that of the BC-PEH, which verified the power density improvement of PEH via a hybridization scheme with EMEH. Additionally, the hybrid harvester exhibits better performance for charging capacitors, such as charging a 2.2 mF capacitor to 8 V within 17 s. It is of great significance to further develop self-powered devices.


2021 ◽  
Vol 6 (51) ◽  
pp. eaaz5796
Author(s):  
I. D. Sîrbu ◽  
G. Moretti ◽  
G. Bortolotti ◽  
M. Bolignari ◽  
S. Diré ◽  
...  

Future robotic systems will be pervasive technologies operating autonomously in unknown spaces that are shared with humans. Such complex interactions make it compulsory for them to be lightweight, soft, and efficient in a way to guarantee safety, robustness, and long-term operation. Such a set of qualities can be achieved using soft multipurpose systems that combine, integrate, and commute between conventional electromechanical and fluidic drives, as well as harvest energy during inactive actuation phases for increased energy efficiency. Here, we present an electrostatic actuator made of thin films and liquid dielectrics combined with rigid polymeric stiffening elements to form a circular electrostatic bellow muscle (EBM) unit capable of out-of-plane contraction. These units are easy to manufacture and can be arranged in arrays and stacks, which can be used as a contractile artificial muscle, as a pump for fluid-driven soft robots, or as an energy harvester. As an artificial muscle, EBMs of 20 to 40 millimeters in diameter can exert forces of up to 6 newtons, lift loads over a hundred times their own weight, and reach contractions of over 40% with strain rates over 1200% per second, with a bandwidth over 10 hertz. As a pump driver, these EBMs produce flow rates of up to 0.63 liters per minute and maximum pressure head of 6 kilopascals, whereas as generator, they reach a conversion efficiency close to 20%. The compact shape, low cost, simple assembling procedure, high reliability, and large contractions make the EBM a promising technology for high-performance robotic systems.


2021 ◽  
Vol 36 (2) ◽  
pp. 1680-1692
Author(s):  
Huakang Xia ◽  
Yinshui Xia ◽  
Ge Shi ◽  
Yidie Ye ◽  
Xiudeng Wang ◽  
...  

2015 ◽  
Vol 69 (13) ◽  
pp. 51-55
Author(s):  
T.-W. Chang ◽  
Y.-Y. Ke ◽  
Z.-H. Lin

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4274
Author(s):  
Eunsuk Choi ◽  
Sunjin Kim ◽  
Jinsil Gong ◽  
Hyeonjeong Sun ◽  
Minjin Kwon ◽  
...  

In this article we report on a 3 × 3 mm tactile interaction sensor that is able to simultaneously detect pressure level, pressure distribution, and shear force direction. The sensor consists of multiple mechanical switches under a conducting diaphragm. An external stimulus is measured by the deflection of the diaphragm and the arrangement of mechanical switches, resulting in low noise, high reliability, and high uniformity. Our sensor is able to detect tactile forces as small as ~50 mgf along with the direction of the shear force. It also distinguishes whether there is a normal pressure during slip motion. We also succeed in detecting the contact shape and the contact motion, demonstrating potential applications in robotics and remote input interfaces. Since our sensor has a simple structure and its function depends only on sensor dimensions, not on an active sensing material, in comparison with previous tactile sensors, our sensor shows high uniformity and reliability for an array-type integration.


2021 ◽  
Vol 79 (6) ◽  
pp. 631-640
Author(s):  
Takaaki Tsunoda ◽  
Takeo Tsukamoto ◽  
Yoichi Ando ◽  
Yasuhiro Hamamoto ◽  
Yoichi Ikarashi ◽  
...  

Electronic devices such as medical instruments implanted in the human body and electronic control units installed in automobiles have a large impact on human life. The electronic circuits in these devices require highly reliable operation. Radiographic testing has recently been in strong demand as a nondestructive way to help ensure high reliability. Companies that use high-density micrometer-scale circuits or lithium-ion batteries require high speed and high magnification inspection of all parts. The authors have developed a new X-ray source supporting these requirements. The X-ray source has a sealed tube with a transmissive target on a diamond window that offers advantages over X-ray sources having a sealed tube with a reflective target. The X-ray source provides high-power-density X-ray with no anode degradation and a longer shelf life. In this paper, the authors will summarize X-ray source classification relevant to electronic device inspection and will detail X-ray source performance requirements and challenges. The paper will also elaborate on technologies employed in the X-ray source including tube design implementations for high-power-density X-ray, high resolution, and high magnification simultaneously; reduced system downtime for automated X-ray inspection; and reduced dosages utilizing quick X-ray on-and-off emission control for protection of sensitive electronic devices.


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