Pub Date : 2019-12-01DOI: 10.1109/PowerMEMS49317.2019.12345678901
P. Nieroda, A. Kusior
The aim of this study was to determine the influence of synthesis method of Cu1.8S material for its thermoelectric properties. The material was synthesized by hydrothermal and high temperature method and then densified by Spark Plasma Sintering (SPS) technique. Structural, phase and chemical composition analyses were examined with X-ray diffraction (XRD) and scanning electron microscopy (SEM). The investigations of thermoelectric properties, i.e.: electrical conductivity, the Seebeck coefficient and the thermal conductivity, were carried out in the temperature range from RT to 910 K. On the basis of the experimental data, the temperature dependencies of the thermoelectric Figure of merit ZT were calculated. Detailed analysis of all obtained results was performed withadditional insight into the role of the synthesis method on received thermoelectric properties. Superionic thermoelectric materials based on Cu2 X (X = S, Se, Te) are intensively studied in recent years due to the very high values of their ZT parameter [1]. Unfortunately, their transport properties are unstable becouse of the high mobility of copper ions [2]. Cu1.8S is much more stable compared to $Cu_{2}S$ and used to be obtained mainly by the mechanical alloying method [3,4]. In this work, the Cu1.8S material was received by hydrothermal synthesis and high-temperature synthesis, and then their transport properties were examined and compared.
本研究的目的是确定Cu1.8S材料的合成方法对其热电性能的影响。采用水热法和高温法合成了该材料，然后采用火花等离子烧结(SPS)技术进行了致密化。用x射线衍射仪(XRD)和扫描电镜(SEM)对其结构、物相和化学成分进行了分析。在RT ~ 910 K的温度范围内进行了热电性能的研究，即电导率、塞贝克系数和导热系数。在实验数据的基础上，计算了热电性能图ZT的温度依赖关系。对所有获得的结果进行了详细的分析，并进一步深入了解了合成方法对接收热电性能的作用。基于Cu2 X (X = S, Se, Te)的超离子热电材料由于其ZT参数非常高，近年来得到了广泛的研究[1]。不幸的是，由于铜离子的高迁移率，它们的输运性质不稳定[2]。Cu1.8S比$Cu_{2}S$稳定得多，过去主要通过机械合金化方法获得[3,4]。本文采用水热合成和高温合成两种方法制备了Cu1.8S材料，并对其输运性质进行了测试和比较。
{"title":"Synthesis and thermoelectric properties of Cu1.8 S","authors":"P. Nieroda, A. Kusior","doi":"10.1109/PowerMEMS49317.2019.12345678901","DOIUrl":"https://doi.org/10.1109/PowerMEMS49317.2019.12345678901","url":null,"abstract":"The aim of this study was to determine the influence of synthesis method of Cu1.8S material for its thermoelectric properties. The material was synthesized by hydrothermal and high temperature method and then densified by Spark Plasma Sintering (SPS) technique. Structural, phase and chemical composition analyses were examined with X-ray diffraction (XRD) and scanning electron microscopy (SEM). The investigations of thermoelectric properties, i.e.: electrical conductivity, the Seebeck coefficient and the thermal conductivity, were carried out in the temperature range from RT to 910 K. On the basis of the experimental data, the temperature dependencies of the thermoelectric Figure of merit ZT were calculated. Detailed analysis of all obtained results was performed withadditional insight into the role of the synthesis method on received thermoelectric properties. Superionic thermoelectric materials based on Cu2 X (X = S, Se, Te) are intensively studied in recent years due to the very high values of their ZT parameter [1]. Unfortunately, their transport properties are unstable becouse of the high mobility of copper ions [2]. Cu1.8S is much more stable compared to $Cu_{2}S$ and used to be obtained mainly by the mechanical alloying method [3,4]. In this work, the Cu1.8S material was received by hydrothermal synthesis and high-temperature synthesis, and then their transport properties were examined and compared.","PeriodicalId":6648,"journal":{"name":"2019 19th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"41 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82374454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1109/PowerMEMS49317.2019.71805306097
N. Garraud, B. Alessandri, P. Gasnier, D. Arnold, S. Boisseau
Magnetodynamic wireless power transfer (WPT), also known as electrodynamic wireless power transfer, is a low-frequency WPT technology based on an electromechanical receiver comprising a permanent magnet moving in a coil. Because of the low-frequency field, this technology is safe around humans and enables transfer through conductive media. In this paper, we focus on the design and the optimization of the power receiver with advanced modelling methods. Two operating modes, namely a continuously rotating mode and a resonant mode, targeting high-power-density and mid-range power transfer respectively, are investigated and compared to previous versions. The fabricated 25-cm3 receiver presents substantial improvements in terms of transferred power (3.3W) and power density (x7) compared to previous receivers in the same conditions of fields.
{"title":"Optimization of a Magnetodynamic Receiver for Versatile Low-Frequency Wireless Power Transfer","authors":"N. Garraud, B. Alessandri, P. Gasnier, D. Arnold, S. Boisseau","doi":"10.1109/PowerMEMS49317.2019.71805306097","DOIUrl":"https://doi.org/10.1109/PowerMEMS49317.2019.71805306097","url":null,"abstract":"Magnetodynamic wireless power transfer (WPT), also known as electrodynamic wireless power transfer, is a low-frequency WPT technology based on an electromechanical receiver comprising a permanent magnet moving in a coil. Because of the low-frequency field, this technology is safe around humans and enables transfer through conductive media. In this paper, we focus on the design and the optimization of the power receiver with advanced modelling methods. Two operating modes, namely a continuously rotating mode and a resonant mode, targeting high-power-density and mid-range power transfer respectively, are investigated and compared to previous versions. The fabricated 25-cm3 receiver presents substantial improvements in terms of transferred power (3.3W) and power density (x7) compared to previous receivers in the same conditions of fields.","PeriodicalId":6648,"journal":{"name":"2019 19th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"15 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81888723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1109/PowerMEMS49317.2019.82063206255
K. Paul, D. Mallick, Saibal Roy
The ubiquitous ambient vibrational energy is a potential candidate for solving the pertinent issue of perpetual powering of the numerous deployed wireless sensor nodes. The major roadblock in the materialization of a fully integrated high-efficiency electromagnetic vibration energy harvester is the lack of CMOS compatible magnetic materials and its integration. This work demonstrates the unique advantage of employing high performance stripe patterned array of magnets instead of conventional thin film of magnets which enhances the electromagnetic coupling factor to 53.03 mWb/m by maximizing the magnetic flux gradient within a small footprint and in a precise location. Further, it explores the benefits of employing compact in-plane moving nonlinear MEMS spring architecture, which till date is relatively unreported, that enhances the bandwidth of operation 3 times as compared with its linear counterpart at the cost of reduced peak load power. This detailed study provides a design guideline and opens up the scope for further design optimization for improving overall performance of MEMS Electromagnetic Vibration Energy Harvesters (EM-VEH).
{"title":"Improved Performances of Wideband MEMS Electromagnetic Vibration Energy Harvesters using Patterned Micro-magnet Arrays","authors":"K. Paul, D. Mallick, Saibal Roy","doi":"10.1109/PowerMEMS49317.2019.82063206255","DOIUrl":"https://doi.org/10.1109/PowerMEMS49317.2019.82063206255","url":null,"abstract":"The ubiquitous ambient vibrational energy is a potential candidate for solving the pertinent issue of perpetual powering of the numerous deployed wireless sensor nodes. The major roadblock in the materialization of a fully integrated high-efficiency electromagnetic vibration energy harvester is the lack of CMOS compatible magnetic materials and its integration. This work demonstrates the unique advantage of employing high performance stripe patterned array of magnets instead of conventional thin film of magnets which enhances the electromagnetic coupling factor to 53.03 mWb/m by maximizing the magnetic flux gradient within a small footprint and in a precise location. Further, it explores the benefits of employing compact in-plane moving nonlinear MEMS spring architecture, which till date is relatively unreported, that enhances the bandwidth of operation 3 times as compared with its linear counterpart at the cost of reduced peak load power. This detailed study provides a design guideline and opens up the scope for further design optimization for improving overall performance of MEMS Electromagnetic Vibration Energy Harvesters (EM-VEH).","PeriodicalId":6648,"journal":{"name":"2019 19th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"32 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89756376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1109/PowerMEMS49317.2019.92321100357
O. Frevchet, S. Boisseau, F. Frassati, V. Josselin, P. Gasnier, N. Garraud, R. Gohier, D. Gibus, S. Brulais, G. Despesse
This paper reports techniques to transfer power and data through metal walls by exploiting acoustic waves using innovative piezoelectric transducer mountings. Instead of permanently gluing piezoelectric elements on both sides of the metal wall as usually proposed, we studied two detachable and reusable solutions and study their associated power performances. These solutions allow to implement quickly Acoustic Power and Data Transfer (APDT) for in-situ demonstration of the technology. Power transmission efficiencies are equivalent to the ones reached with standard designs. These concepts could be applied to develop a portable equipment to supply sensors in closed or metallic operational environments. In addition, the maximum reachable efficiencies can be obtained directly by a Vector Network Analyzer (VNA), enabling the real-time observation of the evolution of power transfer efficiency when moving the transducers.
{"title":"A Versatile Through-Metal-Wall Acoustic Power and Data Transfer Solution","authors":"O. Frevchet, S. Boisseau, F. Frassati, V. Josselin, P. Gasnier, N. Garraud, R. Gohier, D. Gibus, S. Brulais, G. Despesse","doi":"10.1109/PowerMEMS49317.2019.92321100357","DOIUrl":"https://doi.org/10.1109/PowerMEMS49317.2019.92321100357","url":null,"abstract":"This paper reports techniques to transfer power and data through metal walls by exploiting acoustic waves using innovative piezoelectric transducer mountings. Instead of permanently gluing piezoelectric elements on both sides of the metal wall as usually proposed, we studied two detachable and reusable solutions and study their associated power performances. These solutions allow to implement quickly Acoustic Power and Data Transfer (APDT) for in-situ demonstration of the technology. Power transmission efficiencies are equivalent to the ones reached with standard designs. These concepts could be applied to develop a portable equipment to supply sensors in closed or metallic operational environments. In addition, the maximum reachable efficiencies can be obtained directly by a Vector Network Analyzer (VNA), enabling the real-time observation of the evolution of power transfer efficiency when moving the transducers.","PeriodicalId":6648,"journal":{"name":"2019 19th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"28 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90047401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1109/PowerMEMS49317.2019.71805309448
G. Lombardi, M. Lallart, M. Kiziroglou, E. Yeatman
In the present work, a cooperative hybrid energy harvester for scavenging ambient vibrations is presented. The proposed energy harvesting system exploits both piezoelectricity and electromagnetism to harvest rotational energy. More precisely, while the electromagnetic device is devoted to energy harvesting, the piezoelectric element is actually used for efficiently converting the energy of the former. Indeed, in order to improve the electromagnetic transducer’s AC/DC conversion efficiency, a half-wave voltage doubler where the piezo element is driving MOSFETs is employed. Such a motivation is actually explained by the much lower conversion abilities of the piezoelectric transducer compared to the electromagnetic one in the considered structure. Simulation and experimental validations are presented, demonstrating the improvement of the energy conversion efficiency of the electromagnetic transducer.
{"title":"AC/DC power conversion improvement of rotational electromagnetic energy harvesting using piezoelectric elements for active rectification","authors":"G. Lombardi, M. Lallart, M. Kiziroglou, E. Yeatman","doi":"10.1109/PowerMEMS49317.2019.71805309448","DOIUrl":"https://doi.org/10.1109/PowerMEMS49317.2019.71805309448","url":null,"abstract":"In the present work, a cooperative hybrid energy harvester for scavenging ambient vibrations is presented. The proposed energy harvesting system exploits both piezoelectricity and electromagnetism to harvest rotational energy. More precisely, while the electromagnetic device is devoted to energy harvesting, the piezoelectric element is actually used for efficiently converting the energy of the former. Indeed, in order to improve the electromagnetic transducer’s AC/DC conversion efficiency, a half-wave voltage doubler where the piezo element is driving MOSFETs is employed. Such a motivation is actually explained by the much lower conversion abilities of the piezoelectric transducer compared to the electromagnetic one in the considered structure. Simulation and experimental validations are presented, demonstrating the improvement of the energy conversion efficiency of the electromagnetic transducer.","PeriodicalId":6648,"journal":{"name":"2019 19th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"124 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86433889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1109/PowerMEMS49317.2019.61547405924
Y. Tohyama, H. Honma, N. Ishihara, H. Sekiya, H. Toshiyoshi, D. Yamane
We report an energy harvesting technique that generates electrical power from non -stational environmental vibrations. To utilize weak vibrations that are wasted by conventional rectifiers, we employ a voltage-boost rectifier (VBR) circuit. The VBR can convert small AC voltage from vibrational energy harvesters (VEHs) to a DC output voltage for driving a latter circuity, as reported in PowerMEMS 2018. A VBR chip is implemented by the complementary metal -oxide semiconductor (CMOS) technology and experimentally evaluated with an electret-based MEMS VEH. The measurement results reveal that the proposed technique can generate effective DC voltage from weak non-stational vibrations.
{"title":"Energy Harvesting from Non-Stational Environmental Vibrations using a Voltage-Boost Rectifier Circuit","authors":"Y. Tohyama, H. Honma, N. Ishihara, H. Sekiya, H. Toshiyoshi, D. Yamane","doi":"10.1109/PowerMEMS49317.2019.61547405924","DOIUrl":"https://doi.org/10.1109/PowerMEMS49317.2019.61547405924","url":null,"abstract":"We report an energy harvesting technique that generates electrical power from non -stational environmental vibrations. To utilize weak vibrations that are wasted by conventional rectifiers, we employ a voltage-boost rectifier (VBR) circuit. The VBR can convert small AC voltage from vibrational energy harvesters (VEHs) to a DC output voltage for driving a latter circuity, as reported in PowerMEMS 2018. A VBR chip is implemented by the complementary metal -oxide semiconductor (CMOS) technology and experimentally evaluated with an electret-based MEMS VEH. The measurement results reveal that the proposed technique can generate effective DC voltage from weak non-stational vibrations.","PeriodicalId":6648,"journal":{"name":"2019 19th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"10 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91365028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1109/PowerMEMS49317.2019.20515807686
T. Miyoshi, Y. Tanaka, Y. Suzuki
AbstractIn this paper, we investigate the effect of natural frequency of rotational energy harvester (EH) on power generation characteristics during human walking. Based on electromechanical analysis using the arm swing model, it is found that the output power is significantly affected by the natural frequency of the rotor due to the gravitational force. Rotational electret energy harvesters with different natural frequency of the rotor were prototyped, and their output power were characterized by using a 6-axis parallel link robot, which can mimic the arm swing motion for different walking speeds. It is found that, by adjusting the natural frequency of the rotor at 1 Hz, much higher output power has been obtained for a wide range of the walking speeds.
{"title":"Effect of Natural Frequency of Rotational Electret Energy Harvester for Human Walking","authors":"T. Miyoshi, Y. Tanaka, Y. Suzuki","doi":"10.1109/PowerMEMS49317.2019.20515807686","DOIUrl":"https://doi.org/10.1109/PowerMEMS49317.2019.20515807686","url":null,"abstract":"AbstractIn this paper, we investigate the effect of natural frequency of rotational energy harvester (EH) on power generation characteristics during human walking. Based on electromechanical analysis using the arm swing model, it is found that the output power is significantly affected by the natural frequency of the rotor due to the gravitational force. Rotational electret energy harvesters with different natural frequency of the rotor were prototyped, and their output power were characterized by using a 6-axis parallel link robot, which can mimic the arm swing motion for different walking speeds. It is found that, by adjusting the natural frequency of the rotor at 1 Hz, much higher output power has been obtained for a wide range of the walking speeds.","PeriodicalId":6648,"journal":{"name":"2019 19th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"10 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84602261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1109/PowerMEMS49317.2019.71805313239
P. Knapkiewicz, T. Grzebyk
The unique solution of micro-powered and fully functional MEMS device for cold atom spectroscopy is presented. The solution described here may be particularly valuable for CubeSats technology, where low power demand, small dimensions and low weight are absolutely required.The MEMS device is a multilayer silicon-glass structure. The key part of the structure is high-quality glass tube assembled onto silicon-glass planar structure. Ion-sorption micropump and laser induced alkali vapor introduction method were used to build this MEMS device.During tests it was shown that it is possible to generate and maintain a high vacuum $(10^{-7}$ hPa) and control the number of alkali vapors $(sim 10^{-6}$ hPa), where the power demand was about 1 mW. This achievement opens a way to build micro-powered, high-vacuum alkali vapors MEMS cells for atomic devices, including cold atom spectroscopy.
{"title":"Dynamically stabilized high vacuum inside rubidium vapor MEMS cell for cold atom spectroscopy","authors":"P. Knapkiewicz, T. Grzebyk","doi":"10.1109/PowerMEMS49317.2019.71805313239","DOIUrl":"https://doi.org/10.1109/PowerMEMS49317.2019.71805313239","url":null,"abstract":"The unique solution of micro-powered and fully functional MEMS device for cold atom spectroscopy is presented. The solution described here may be particularly valuable for CubeSats technology, where low power demand, small dimensions and low weight are absolutely required.The MEMS device is a multilayer silicon-glass structure. The key part of the structure is high-quality glass tube assembled onto silicon-glass planar structure. Ion-sorption micropump and laser induced alkali vapor introduction method were used to build this MEMS device.During tests it was shown that it is possible to generate and maintain a high vacuum $(10^{-7}$ hPa) and control the number of alkali vapors $(sim 10^{-6}$ hPa), where the power demand was about 1 mW. This achievement opens a way to build micro-powered, high-vacuum alkali vapors MEMS cells for atomic devices, including cold atom spectroscopy.","PeriodicalId":6648,"journal":{"name":"2019 19th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"16 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82022949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1109/PowerMEMS49317.2019.82063200604
N. Hillier, S. Yong, S. Beeby
The integration of flexible supercapacitors into wearable technologies has seen a steady increase over the previous decade. Offering promising power and energy densities, and significant design freedom, these energy storage devices will enable self-powering garments. The performance of these devices depends on many factors, with the electrode material, configuration and choice of electrolyte all contributing to the final device. One primary performance indicator is the cycle stability, where a device is tested under many full electrochemical cycles and the decay of the performance evaluated. A performance indicator that is often overlooked however, is the calendar stability. Given these devices need to perform for the lifetime of the garment without the possibility of replacement, this omission from the literature seems significant. This work begins the investigation of the stability over time by characterising a textile supported supercapacitor, stored in a number of environments. Under the test condition these devices were found to have a calendar life of 35 days and under non-test conditions were found to have calendar lives of $lt6$ days. An investigation of the ionic conductivity of the electrolyte soaked textile layer suggests the evaporation of the electrolyte is the primary device failure mechanism. This calls into question the validity of using polyvinyl alcohol as the polymer agent in future quasi-solid state electrolytes.
{"title":"Calendar Life of Textile Supercapacitors","authors":"N. Hillier, S. Yong, S. Beeby","doi":"10.1109/PowerMEMS49317.2019.82063200604","DOIUrl":"https://doi.org/10.1109/PowerMEMS49317.2019.82063200604","url":null,"abstract":"The integration of flexible supercapacitors into wearable technologies has seen a steady increase over the previous decade. Offering promising power and energy densities, and significant design freedom, these energy storage devices will enable self-powering garments. The performance of these devices depends on many factors, with the electrode material, configuration and choice of electrolyte all contributing to the final device. One primary performance indicator is the cycle stability, where a device is tested under many full electrochemical cycles and the decay of the performance evaluated. A performance indicator that is often overlooked however, is the calendar stability. Given these devices need to perform for the lifetime of the garment without the possibility of replacement, this omission from the literature seems significant. This work begins the investigation of the stability over time by characterising a textile supported supercapacitor, stored in a number of environments. Under the test condition these devices were found to have a calendar life of 35 days and under non-test conditions were found to have calendar lives of $lt6$ days. An investigation of the ionic conductivity of the electrolyte soaked textile layer suggests the evaporation of the electrolyte is the primary device failure mechanism. This calls into question the validity of using polyvinyl alcohol as the polymer agent in future quasi-solid state electrolytes.","PeriodicalId":6648,"journal":{"name":"2019 19th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"472 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75160387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-12-01DOI: 10.1109/PowerMEMS49317.2019.82063205204
A. Brenes, D. Kim, É. Lefeuvre, N. Kim, H. Kang, C. Yoo, C. I. Cheon, S. Han
This paper compares the system-level parameters and output power of soft-material and hard-material piezoelectric energy harvesters taking into account the material softening nonlinear behavior. We validate the approach by verifying the compatibility with conclusions available in the literature at material level. Among the results, our system-level characterization confirms that soft-type materials behave intrinsically more nonlinearly and that neglecting their nonlinear behavior can lead to wrong conclusions about the system-level coupling coefficient. Then, we compare the generators in terms of power delivered to a load when actuated by a shaker. The power delivered by the hard-type transducer increases faster than the power delivered by the soft-type transducer when the acceleration amplitude increases which is also consistent with our characterization results and validates the system-level approach.
{"title":"Towards the unification of material-level and system-level approaches: nonlinear characterization of hard and soft-PZT energy harvesters","authors":"A. Brenes, D. Kim, É. Lefeuvre, N. Kim, H. Kang, C. Yoo, C. I. Cheon, S. Han","doi":"10.1109/PowerMEMS49317.2019.82063205204","DOIUrl":"https://doi.org/10.1109/PowerMEMS49317.2019.82063205204","url":null,"abstract":"This paper compares the system-level parameters and output power of soft-material and hard-material piezoelectric energy harvesters taking into account the material softening nonlinear behavior. We validate the approach by verifying the compatibility with conclusions available in the literature at material level. Among the results, our system-level characterization confirms that soft-type materials behave intrinsically more nonlinearly and that neglecting their nonlinear behavior can lead to wrong conclusions about the system-level coupling coefficient. Then, we compare the generators in terms of power delivered to a load when actuated by a shaker. The power delivered by the hard-type transducer increases faster than the power delivered by the soft-type transducer when the acceleration amplitude increases which is also consistent with our characterization results and validates the system-level approach.","PeriodicalId":6648,"journal":{"name":"2019 19th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"13 1","pages":"1-2"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74566199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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