The Experts below are selected from a list of 3165 Experts worldwide ranked by ideXlab platform
Jae-hyun Ryou - One of the best experts on this subject based on the ideXlab platform.
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Biocompatible and sustainable power supply for self-powered wearable and implantable electronics using III-nitride thin-film-based flexible Piezoelectric Generator
Nano Energy, 2019Co-Authors: Jie Chen, Noor Nabulsi, Heidi Johnson, Weijie Wang, Jae-hyun RyouAbstract:Abstract Energy harvesters that scavenge biomechanical energy are promising power supply candidates for wearable and implantable electronics. Of the most widely used energy harvesters, Piezoelectric Generators can generate more electric charge than their triboelectric counterparts with similar device size, thus are more suitable to make compact wearable devices. However, most high-power Piezoelectric Generators are made from lead zirconate titanate, making them undesirable for wearable applications due to the toxic lead element. In this study, a flexible Piezoelectric Generator (F-PEG) is fabricated with chemically stable and biocompatible Group-III-nitride (III-N) thin film by a layer-transfer method. The III-N thin-film F-PEG can generate an open-circuit voltage of 50 V, a short-circuit current of 15 µA, and a maximum power of 167 µW at a load resistance of 5 MΩ. Applications of the III-N thin-film F-PEG are demonstrated by directly powering electronics such as light-emitting diodes and electric watches, and by charging commercial capacitors and batteries to operate an optical pulse sensor. Furthermore, the III-N thin-film F-PEG shows good durability and a stable output after being subjected to severe buckling tests of over 30,000 cycles.
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High-Output Lead-Free Flexible Piezoelectric Generator Using Single-Crystalline GaN Thin Film.
ACS applied materials & interfaces, 2018Co-Authors: Jie Chen, Weijie Wang, Zhong Lin Wang, Haiyang Zou, Shahab Shervin, Sara Pouladi, Jae-hyun RyouAbstract:Piezoelectric Generators (PEGs) are a promising power source for future self-powered electronics by converting ubiquitous ambient mechanical energy into electricity. However, most of the high-output PEGs are made from lead zirconate titanate, in which the hazardous lead could be a potential risk to both humans and environment, limiting their real applications. III-Nitride (III-N) can be a potential candidate to make stable, safe, and efficient PEGs due to its high chemical stability and Piezoelectricity. Also, PEGs are preferred to be flexible rather than rigid, to better harvest the low-magnitude mechanical energy. Herein, a high-output, lead-free, and flexible PEG (F-PEG) is made from GaN thin film by transferring a single-crystalline epitaxial layer from silicon substrate to a flexible substrate. The output voltage, current density, and power density can reach 28 V, 1 μA·cm–2, and 6 μW·cm–2, respectively, by bending the F-PEG. The generated electric power by human finger bending is high enough to light...
Chan-sei Yoo - One of the best experts on this subject based on the ideXlab platform.
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Tunable unipolar synchronized electric charge extraction strategy for Piezoelectric energy harvesting
Journal of Intelligent Material Systems and Structures, 2019Co-Authors: Alexis Brenes, Elie Lefeuvre, Seonho Seok, Chan-sei YooAbstract:This article focuses on an intelligent control strategy to improve the performances of shunt-rectifier architectures for vibration energy harvesting. It demonstrates how proper tuning can improve the frequency bandwidth and maximum power of unipolar synchronized electric charge extraction architectures. For resonators with strong enough coupling (k 2 Q. p=2), tuning the duration of charge extraction with the oscillation frequency improves the power harvesting performances. The main differences with other similar solutions such as unipolar synchronized electric charge extraction without tuning strategy or tunable synchronized electric charge extraction are illustrated. In particular, we show how the choice of the shunt rectifier significantly affects the power response of the Generator due to electromechanical coupling phenomenon. The analytical study is experimentally validated on a cantilever-based Piezoelectric Generator.
Jie Chen - One of the best experts on this subject based on the ideXlab platform.
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Biocompatible and sustainable power supply for self-powered wearable and implantable electronics using III-nitride thin-film-based flexible Piezoelectric Generator
Nano Energy, 2019Co-Authors: Jie Chen, Noor Nabulsi, Heidi Johnson, Weijie Wang, Jae-hyun RyouAbstract:Abstract Energy harvesters that scavenge biomechanical energy are promising power supply candidates for wearable and implantable electronics. Of the most widely used energy harvesters, Piezoelectric Generators can generate more electric charge than their triboelectric counterparts with similar device size, thus are more suitable to make compact wearable devices. However, most high-power Piezoelectric Generators are made from lead zirconate titanate, making them undesirable for wearable applications due to the toxic lead element. In this study, a flexible Piezoelectric Generator (F-PEG) is fabricated with chemically stable and biocompatible Group-III-nitride (III-N) thin film by a layer-transfer method. The III-N thin-film F-PEG can generate an open-circuit voltage of 50 V, a short-circuit current of 15 µA, and a maximum power of 167 µW at a load resistance of 5 MΩ. Applications of the III-N thin-film F-PEG are demonstrated by directly powering electronics such as light-emitting diodes and electric watches, and by charging commercial capacitors and batteries to operate an optical pulse sensor. Furthermore, the III-N thin-film F-PEG shows good durability and a stable output after being subjected to severe buckling tests of over 30,000 cycles.
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High-Output Lead-Free Flexible Piezoelectric Generator Using Single-Crystalline GaN Thin Film.
ACS applied materials & interfaces, 2018Co-Authors: Jie Chen, Weijie Wang, Zhong Lin Wang, Haiyang Zou, Shahab Shervin, Sara Pouladi, Jae-hyun RyouAbstract:Piezoelectric Generators (PEGs) are a promising power source for future self-powered electronics by converting ubiquitous ambient mechanical energy into electricity. However, most of the high-output PEGs are made from lead zirconate titanate, in which the hazardous lead could be a potential risk to both humans and environment, limiting their real applications. III-Nitride (III-N) can be a potential candidate to make stable, safe, and efficient PEGs due to its high chemical stability and Piezoelectricity. Also, PEGs are preferred to be flexible rather than rigid, to better harvest the low-magnitude mechanical energy. Herein, a high-output, lead-free, and flexible PEG (F-PEG) is made from GaN thin film by transferring a single-crystalline epitaxial layer from silicon substrate to a flexible substrate. The output voltage, current density, and power density can reach 28 V, 1 μA·cm–2, and 6 μW·cm–2, respectively, by bending the F-PEG. The generated electric power by human finger bending is high enough to light...
Alexis Brenes - One of the best experts on this subject based on the ideXlab platform.
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Tunable unipolar synchronized electric charge extraction strategy for Piezoelectric energy harvesting
Journal of Intelligent Material Systems and Structures, 2019Co-Authors: Alexis Brenes, Elie Lefeuvre, Seonho Seok, Chan-sei YooAbstract:This article focuses on an intelligent control strategy to improve the performances of shunt-rectifier architectures for vibration energy harvesting. It demonstrates how proper tuning can improve the frequency bandwidth and maximum power of unipolar synchronized electric charge extraction architectures. For resonators with strong enough coupling (k 2 Q. p=2), tuning the duration of charge extraction with the oscillation frequency improves the power harvesting performances. The main differences with other similar solutions such as unipolar synchronized electric charge extraction without tuning strategy or tunable synchronized electric charge extraction are illustrated. In particular, we show how the choice of the shunt rectifier significantly affects the power response of the Generator due to electromechanical coupling phenomenon. The analytical study is experimentally validated on a cantilever-based Piezoelectric Generator.
P K Wright - One of the best experts on this subject based on the ideXlab platform.
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A Piezoelectric vibration based Generator for wireless electronics
Smart Materials and Structures, 2004Co-Authors: Shad Roundy, P K WrightAbstract:Enabling technologies for wireless sensor networks have gained considerable attention in research communities over the past few years. It is highly desirable, even necessary in certain situations, for wireless sensor nodes to be self-powered. With this goal in mind, a vibration based Piezoelectric Generator has been developed as an enabling technology for wireless sensor networks. The focus of this paper is to discuss the modeling, design, and optimization ofa Piezoelectric Generator based on a two-layer bending element. An analytical model of the Generator has been developed andvalidated. In addition to providing intuitive design insight, the model has been used as the basis for design optimization. Designs of 1 cm3 in size generated using the model have demonstrated a power output of 375 µW from a vibration source of 2.5 m s−2 at 120 Hz. Furthermore, a 1 cm3 Generator has been used to power a custom designed 1.9 GHz radio transmitter from the same vibration source