Pub Date : 2021-12-06DOI: 10.1109/PowerMEMS54003.2021.9658389
O. Freychet, S. Boisseau, F. Frassati, N. Garraud, P. Gasnier, G. Despesse
Acoustic power transfer is a wireless power transfer technology that enables to supply sensors placed behind metal walls by using acoustic waves generated by piezoelectric transducers positioned on both sides of the wall. The state of the art reports that high levels of powers, up to hundreds of watts, can be transmitted but at the cost of high input voltage levels, making the control electronics complicated, low-efficient and even hazardous. In this paper, we study and validate experimentally the use a piezoelectric stack to generate the acoustic waves to transmit high power levels with low actuation voltages. By using a stack of four piezoelectric disks, the transmitted power is multiplied by 5 compared to a single disk for the same excitation voltage, and the power density is multiplied by 2, reaching 8.2 mW/V2/cm3.
{"title":"Piezoelectric stacks to increase the transmitted power of acoustic power transfer through metal walls","authors":"O. Freychet, S. Boisseau, F. Frassati, N. Garraud, P. Gasnier, G. Despesse","doi":"10.1109/PowerMEMS54003.2021.9658389","DOIUrl":"https://doi.org/10.1109/PowerMEMS54003.2021.9658389","url":null,"abstract":"Acoustic power transfer is a wireless power transfer technology that enables to supply sensors placed behind metal walls by using acoustic waves generated by piezoelectric transducers positioned on both sides of the wall. The state of the art reports that high levels of powers, up to hundreds of watts, can be transmitted but at the cost of high input voltage levels, making the control electronics complicated, low-efficient and even hazardous. In this paper, we study and validate experimentally the use a piezoelectric stack to generate the acoustic waves to transmit high power levels with low actuation voltages. By using a stack of four piezoelectric disks, the transmitted power is multiplied by 5 compared to a single disk for the same excitation voltage, and the power density is multiplied by 2, reaching 8.2 mW/V2/cm3.","PeriodicalId":165158,"journal":{"name":"2021 IEEE 20th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"55 6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130533816","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 : 2021-12-06DOI: 10.1109/PowerMEMS54003.2021.9658354
N. Jackson
Narrow bandwidths is considered a major limitation of MEMS piezoelectric energy harvesters. Recent research has demonstrated that vertical moving masses embedded within a stationary mass is a viable option to increasing bandwidth. The concept operates by altering the effective mass during oscillation of the cantilever. Secondary impact forces caused from bouncing of the movable mass results in non-linear dynamics. This paper investigates the effect of the impact force and secondary impact forces due to the bouncing movable mass. The phenomenon was investigated using multiple movable mass balls which either enable or eliminate bouncing to determine the role that secondary impacts have on bandwidth. The results demonstrate that masses with secondary bouncing impacts have significantly larger bandwidth (26 Hz) compared to non-bouncing masses (4.32 Hz). However, the non-bouncing masses still provide higher bandwidth than a non-moving mass (1.3 Hz), due to the change in effective mass. The secondary impact of the mass generates complex output waveforms with multiple frequencies compared to a stationary mass and non-bouncing masses which demonstrate linear sinusoidal output waveforms.
{"title":"Secondary Impact bandwidth effects using Embedded Vertical Moving Mass Energy Harvester","authors":"N. Jackson","doi":"10.1109/PowerMEMS54003.2021.9658354","DOIUrl":"https://doi.org/10.1109/PowerMEMS54003.2021.9658354","url":null,"abstract":"Narrow bandwidths is considered a major limitation of MEMS piezoelectric energy harvesters. Recent research has demonstrated that vertical moving masses embedded within a stationary mass is a viable option to increasing bandwidth. The concept operates by altering the effective mass during oscillation of the cantilever. Secondary impact forces caused from bouncing of the movable mass results in non-linear dynamics. This paper investigates the effect of the impact force and secondary impact forces due to the bouncing movable mass. The phenomenon was investigated using multiple movable mass balls which either enable or eliminate bouncing to determine the role that secondary impacts have on bandwidth. The results demonstrate that masses with secondary bouncing impacts have significantly larger bandwidth (26 Hz) compared to non-bouncing masses (4.32 Hz). However, the non-bouncing masses still provide higher bandwidth than a non-moving mass (1.3 Hz), due to the change in effective mass. The secondary impact of the mass generates complex output waveforms with multiple frequencies compared to a stationary mass and non-bouncing masses which demonstrate linear sinusoidal output waveforms.","PeriodicalId":165158,"journal":{"name":"2021 IEEE 20th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"153 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116402962","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 : 2021-12-06DOI: 10.1109/PowerMEMS54003.2021.9658360
A. Morel, D. Gibus, G. Pillonnet, A. Badel
This paper focuses on electrically-based solutions for tuning the resonant frequency of piezoelectric vibrations energy harvesters in order to compensate for aging or vibration frequency shifts. We present the theory behind electrical frequency tuning, and show that a strong electromechanical coupling associated with two-tuning electrical interfaces allow to reach relatively large frequency tuning ranges. Such solution requires the design of strongly coupled harvesters as well as the design of self-adaptive self-powered electrical interfaces, but, compared to other design approaches, requires much less volume and energy.
{"title":"Opportunities for electrically-based frequency tuning of piezoelectric vibration energy harvesters","authors":"A. Morel, D. Gibus, G. Pillonnet, A. Badel","doi":"10.1109/PowerMEMS54003.2021.9658360","DOIUrl":"https://doi.org/10.1109/PowerMEMS54003.2021.9658360","url":null,"abstract":"This paper focuses on electrically-based solutions for tuning the resonant frequency of piezoelectric vibrations energy harvesters in order to compensate for aging or vibration frequency shifts. We present the theory behind electrical frequency tuning, and show that a strong electromechanical coupling associated with two-tuning electrical interfaces allow to reach relatively large frequency tuning ranges. Such solution requires the design of strongly coupled harvesters as well as the design of self-adaptive self-powered electrical interfaces, but, compared to other design approaches, requires much less volume and energy.","PeriodicalId":165158,"journal":{"name":"2021 IEEE 20th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116531537","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 : 2021-12-06DOI: 10.1109/powermems54003.2021.9658369
{"title":"PowerMEMS 2021 Welcome","authors":"","doi":"10.1109/powermems54003.2021.9658369","DOIUrl":"https://doi.org/10.1109/powermems54003.2021.9658369","url":null,"abstract":"","PeriodicalId":165158,"journal":{"name":"2021 IEEE 20th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128795111","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 : 2021-12-06DOI: 10.1109/PowerMEMS54003.2021.9658366
O. Freychet, F. Frassati, S. Boisseau, N. Garraud, P. Gasnier, G. Despesse
Powering remote sensor nodes placed behind walls without drilling holes is of great interest for many industrial processes and applications. Acoustic power transfer using two piezoelectric transducers placed on both sides of the wall is a proven technology to answer this need. In this paper, we demonstrate that the use of an intermediary layer placed between the emitter and the wall results in a strong increase of the transmitted power: experimentally, the transmitted power is multiplied by two for the same driving voltage. We also show that intermediary layers strongly simplify the identification and the control of the optimal excitation frequency.
{"title":"Intermediate layer to improve the performances and the frequency control of acoustic power transfer systems","authors":"O. Freychet, F. Frassati, S. Boisseau, N. Garraud, P. Gasnier, G. Despesse","doi":"10.1109/PowerMEMS54003.2021.9658366","DOIUrl":"https://doi.org/10.1109/PowerMEMS54003.2021.9658366","url":null,"abstract":"Powering remote sensor nodes placed behind walls without drilling holes is of great interest for many industrial processes and applications. Acoustic power transfer using two piezoelectric transducers placed on both sides of the wall is a proven technology to answer this need. In this paper, we demonstrate that the use of an intermediary layer placed between the emitter and the wall results in a strong increase of the transmitted power: experimentally, the transmitted power is multiplied by two for the same driving voltage. We also show that intermediary layers strongly simplify the identification and the control of the optimal excitation frequency.","PeriodicalId":165158,"journal":{"name":"2021 IEEE 20th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122011752","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 : 2021-12-06DOI: 10.1109/PowerMEMS54003.2021.9658413
Kenta Tsuji, Masayasu Yoshida, I. Kanno
In this study, we fabricated all-solid-state amorphous thin-film lithium-ion batteries (LIBs) on glass or polyimide substrates by RF-sputtering and evaluated their electrochemical performance. The thin-film LIBs were composed of amorphous multilayer of lithium-doped vanadium oxide, lithium phosphorus oxynitride (LiPON), and Si as cathode, electrolyte, and anode, respectively. We measured cyclic voltammetry on the thin-film battery and confirmed the charge and discharge peaks at around 4.2 V and 1.5 V, respectively. The initial area discharge capacity of the amorphous thin-film LIBs was 8.0 μAh/cm2 and 5.4 μAh/cm2 on glass and PI substrates, respectively.
{"title":"Fabrication of all-solid-state amorphous thin-film Lithium-ion batteries","authors":"Kenta Tsuji, Masayasu Yoshida, I. Kanno","doi":"10.1109/PowerMEMS54003.2021.9658413","DOIUrl":"https://doi.org/10.1109/PowerMEMS54003.2021.9658413","url":null,"abstract":"In this study, we fabricated all-solid-state amorphous thin-film lithium-ion batteries (LIBs) on glass or polyimide substrates by RF-sputtering and evaluated their electrochemical performance. The thin-film LIBs were composed of amorphous multilayer of lithium-doped vanadium oxide, lithium phosphorus oxynitride (LiPON), and Si as cathode, electrolyte, and anode, respectively. We measured cyclic voltammetry on the thin-film battery and confirmed the charge and discharge peaks at around 4.2 V and 1.5 V, respectively. The initial area discharge capacity of the amorphous thin-film LIBs was 8.0 μAh/cm2 and 5.4 μAh/cm2 on glass and PI substrates, respectively.","PeriodicalId":165158,"journal":{"name":"2021 IEEE 20th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125730863","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 : 2021-12-06DOI: 10.1109/PowerMEMS54003.2021.9658368
S. Yong, N. Hillier, S. Beeby
This paper reports the design, fabrication and characterization of a hybrid energy storage system, with a textile based rechargeable zinc-ion battery connected in parallel with a textile supercapacitor. The proposed devices were implemented on polyester-cotton textiles with a polymer separator integrated within the textile. The cathode and anode of the zinc-ion battery and the supercapacitor’s carbon electrodes were fabricated with low cost materials via spray deposition. The proposed hybrid energy storage system achieved an areal capacity of 46.6 μAh.cm−2 at 1 mA.cm−2 discharge current within the potential window of 1.9 V to 0.9 V.
本文报道了一种基于纺织品的可充电锌离子电池与纺织品超级电容器并联的混合储能系统的设计、制造和表征。所提出的装置在涤棉纺织品上实现，并在纺织品中集成了聚合物分离器。采用喷雾沉积的方法制备了锌离子电池的正极、负极和超级电容器的碳电极。该混合储能系统的面容量达到46.6 μAh。cm−2在1ma。在1.9 V ~ 0.9 V的电位窗口内，cm−2的放电电流。
{"title":"Textile-based Hybrid Energy Storage System","authors":"S. Yong, N. Hillier, S. Beeby","doi":"10.1109/PowerMEMS54003.2021.9658368","DOIUrl":"https://doi.org/10.1109/PowerMEMS54003.2021.9658368","url":null,"abstract":"This paper reports the design, fabrication and characterization of a hybrid energy storage system, with a textile based rechargeable zinc-ion battery connected in parallel with a textile supercapacitor. The proposed devices were implemented on polyester-cotton textiles with a polymer separator integrated within the textile. The cathode and anode of the zinc-ion battery and the supercapacitor’s carbon electrodes were fabricated with low cost materials via spray deposition. The proposed hybrid energy storage system achieved an areal capacity of 46.6 μAh.cm−2 at 1 mA.cm−2 discharge current within the potential window of 1.9 V to 0.9 V.","PeriodicalId":165158,"journal":{"name":"2021 IEEE 20th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131557998","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 : 2021-12-06DOI: 10.1109/PowerMEMS54003.2021.9658397
Jia Lu, Yuji Suzuki
Piezoelectrets are porous space-charged polymers with high piezoelectric coefficients and excellent softness. They have found applications in making vibrational or kinetic energy harvesters, acoustic sensors and so on. In the present study, an all-polymer multilayer piezoelectret made from thin parylene-C membranes, high-performance dip-coated CYTOP electrets and flexible PEDOT:PSS electrodes is micro-fabricated for push-button energy harvester. To avoid electret discharge, mesh-like spacers are formed in each layer. The piezoelectret is charged with soft X-ray to its critical voltage for air breakdown. Up to 41 μJ electrical energy has been generated with the 8-layer prototype at a pushing force of only 1 N. Its piezoelectric coefficient d33 reaches 125 nC/N and its energy density is 62 μJ/cm3/N, which is much higher than that of commercialized push-button energy harvesters.
{"title":"Push-Button Energy Harvester with Ultra-Soft All-Polymer Piezoelectret","authors":"Jia Lu, Yuji Suzuki","doi":"10.1109/PowerMEMS54003.2021.9658397","DOIUrl":"https://doi.org/10.1109/PowerMEMS54003.2021.9658397","url":null,"abstract":"Piezoelectrets are porous space-charged polymers with high piezoelectric coefficients and excellent softness. They have found applications in making vibrational or kinetic energy harvesters, acoustic sensors and so on. In the present study, an all-polymer multilayer piezoelectret made from thin parylene-C membranes, high-performance dip-coated CYTOP electrets and flexible PEDOT:PSS electrodes is micro-fabricated for push-button energy harvester. To avoid electret discharge, mesh-like spacers are formed in each layer. The piezoelectret is charged with soft X-ray to its critical voltage for air breakdown. Up to 41 μJ electrical energy has been generated with the 8-layer prototype at a pushing force of only 1 N. Its piezoelectric coefficient d33 reaches 125 nC/N and its energy density is 62 μJ/cm3/N, which is much higher than that of commercialized push-button energy harvesters.","PeriodicalId":165158,"journal":{"name":"2021 IEEE 20th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116768862","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 : 2021-12-06DOI: 10.1109/PowerMEMS54003.2021.9658409
Markus Pollak, M. Kiziroglou, S. Wright, P. Spies
This paper describes the current results of research done on an electrical power management circuit for a dynamic temperature energy harvesting generator. It has been designed for use on the fuselage of an aircraft, where high temperature gradients can appear during start and landing. For laboratory tests, the system was put into a climate chamber to emulate similar temperatures from −40 to 20 degrees Celsius. In this work it has been focused mainly on the power conversion side to deliver energy to small systems in the voltage range of 1.8 to 5V. Therefore, a recently at Fraunhofer IIS developed dc-dc converter ASIC (application-specific integrated circuit) was used to handle both positive and negative voltages – which are obtained from the thermoelectric generator (TEG) in the scenario. The chip can cold-start from 35 mV and has an integrated MPPT (maximum-powerpoint-tracking) unit.
{"title":"Cold-Starting Switched-Inductor Bipolar Power Management for Dynamic Thermoelectric Harvesting","authors":"Markus Pollak, M. Kiziroglou, S. Wright, P. Spies","doi":"10.1109/PowerMEMS54003.2021.9658409","DOIUrl":"https://doi.org/10.1109/PowerMEMS54003.2021.9658409","url":null,"abstract":"This paper describes the current results of research done on an electrical power management circuit for a dynamic temperature energy harvesting generator. It has been designed for use on the fuselage of an aircraft, where high temperature gradients can appear during start and landing. For laboratory tests, the system was put into a climate chamber to emulate similar temperatures from −40 to 20 degrees Celsius. In this work it has been focused mainly on the power conversion side to deliver energy to small systems in the voltage range of 1.8 to 5V. Therefore, a recently at Fraunhofer IIS developed dc-dc converter ASIC (application-specific integrated circuit) was used to handle both positive and negative voltages – which are obtained from the thermoelectric generator (TEG) in the scenario. The chip can cold-start from 35 mV and has an integrated MPPT (maximum-powerpoint-tracking) unit.","PeriodicalId":165158,"journal":{"name":"2021 IEEE 20th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133309543","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 : 2021-12-06DOI: 10.1109/PowerMEMS54003.2021.9658373
M. Rosso, A. Corigliano, R. Ardito
This work presents an investigation of different approaches for modelling the magnetic force between permanent magnets for realizing the frequency up-conversion (FuC) in piezoelectric vibration energy harvesters (PVEH). Different analytical models are compared with finite element analyses (FEA). After the investigation, the FuC mechanism is applied on a meso-scale case study and dynamic analyses in the time domain are performed in case of harmonic monochromatic acceleration signal on the device at low-frequency. Both the repulsive and the attractive layouts of the magnets are considered and a larger amount of power is recovered in case of repulsive configuration.
{"title":"An investigation on the magnetic interaction for frequency up-converting piezoelectric vibration energy harvesters","authors":"M. Rosso, A. Corigliano, R. Ardito","doi":"10.1109/PowerMEMS54003.2021.9658373","DOIUrl":"https://doi.org/10.1109/PowerMEMS54003.2021.9658373","url":null,"abstract":"This work presents an investigation of different approaches for modelling the magnetic force between permanent magnets for realizing the frequency up-conversion (FuC) in piezoelectric vibration energy harvesters (PVEH). Different analytical models are compared with finite element analyses (FEA). After the investigation, the FuC mechanism is applied on a meso-scale case study and dynamic analyses in the time domain are performed in case of harmonic monochromatic acceleration signal on the device at low-frequency. Both the repulsive and the attractive layouts of the magnets are considered and a larger amount of power is recovered in case of repulsive configuration.","PeriodicalId":165158,"journal":{"name":"2021 IEEE 20th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS)","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123645161","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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