太阳能供电的传感器节点在电池充满电时会产生过剩的能量,如不加以利用会被浪费。提出一种基于太阳能约束的可靠数据传输方法 RDDMSC(Reliable Data Delivery Method based on Solar Constraint),利用过剩的能量自适应地调整通信中纠错...太阳能供电的传感器节点在电池充满电时会产生过剩的能量,如不加以利用会被浪费。提出一种基于太阳能约束的可靠数据传输方法 RDDMSC(Reliable Data Delivery Method based on Solar Constraint),利用过剩的能量自适应地调整通信中纠错码的冗余度,在网络寿命保持不变的情况下提高传输的可靠性。将问题描述为在有能量约束时最大限度地保证端到端数据包的传输率。证明了在链路质量不差的情况下目标函数一定是凹函数,进而采用凸优化来解决可靠传输问题。实验结果表明,RDDMSC能够有效地使用过剩能量来能够提高数据传输率。展开更多
A novel cement matrix smart piezoelectric composite and its application as sensing element are presented.A cement matrix smart piezoelectric composite piece encapsulated in a cement mortar formed a practical sensor, a...A novel cement matrix smart piezoelectric composite and its application as sensing element are presented.A cement matrix smart piezoelectric composite piece encapsulated in a cement mortar formed a practical sensor, and it was tested on material test system with cyclic loading.According to the theoretical analysis, the function of the cement matrix piezoelectric sensor output voltage was expressed in terms of the magnitude of the input cyclic loading amplitude and frequency.The curve fitting of gain function that is defined as sensor′s gain factor under different frequencies of input loading was carried out. From the results of curve fitting, it is found that the cement matrix smart piezoelectric composite has a simple relationship between input loading and output voltage.Therefore the cement matrix piezoelectric composite sensor is suitable to be applied in structural health monitoring.展开更多
A new self-powered active gas sensor for realtime monitoring of automotive exhaust gas was devised.The pipe-shaped device was fabricated from polydimethylsiloxane/polypyrrole(PDMS/Ppy)triboelectric gas-sensing unit ar...A new self-powered active gas sensor for realtime monitoring of automotive exhaust gas was devised.The pipe-shaped device was fabricated from polydimethylsiloxane/polypyrrole(PDMS/Ppy)triboelectric gas-sensing unit arrays.The gas-sensing units can actively convert the mechanical energy of gas flow into a triboelectric current.The output current signal depends on the species and concentrations of the target chemical gases(CO,NH3,NO)in the gas flow,and thus can be used as a sensing signal.The device consists of seven gas-sensing units with different Ppy derivatives.As the different sensing units respond to the gases in different ways,the device can differentiate between gas species.The working mechanism is attributed to the coupling effect between the triboelectric effect of PDMS/Ppy and the gas-sensing properties of Ppy.The device can be installed in the tailpipe of an automobile,and can thus analyze the exhaust gas in real time without the need for any external electrical power.The results of the present study spur a new research direction for the development of automotive exhaust gas monitoring systems,thus playing an important role in the detection of air pollution.展开更多
Recently, triboelectric generator(TEG) has attracted a lot of attention due to its high output voltage and low-cost fabrication process. Here, a novel cubic TEG box is designed, which has separated electrodes on diffe...Recently, triboelectric generator(TEG) has attracted a lot of attention due to its high output voltage and low-cost fabrication process. Here, a novel cubic TEG box is designed, which has separated electrodes on different surfaces. Thanks to the specially designed structure, it can scavenge vibration energy from all directions. Firstly the device is investigated through finite element method(FEM) simulation. Then the device is evaluated by experiments. The measuremental results show that this device can generate an amount of 25 n C charge during once shake by charging a 10 n F capacitor. Besides, an output voltage about 100 V is obtained, which is able to directly light up several light-emitting diodes(LEDs) simultaneously. At last, the device is utilized as a self-powered orientation sensor, which shows explicit directivity. This work extends the applications of TEG for ambient vibration energy harvesting techniques and the self-powered orientation sensor.展开更多
Detecting/sensing targets underwater has very important applications in environmental study, civil engineering and national security. In this paper, an organic-film based triboelectric nanogenerator （TENG） has been ...Detecting/sensing targets underwater has very important applications in environmental study, civil engineering and national security. In this paper, an organic-film based triboelectric nanogenerator （TENG） has been successfully demonstrated for the first time as a self-powered and high sensitivity acoustic sensor to detect underwater targets at low frequencies around 100 Hz. This innovative, cost-effective, simple-design TENG consists of a thin-film-based Cu electrode and a polytetrafluoroethylene （PTFE） film with nanostructures on its surfaces. On the basis of the coupling effect between triboelectrification and electrostatic induction, the sensor generates electrical output signals in response to incident sound waves. Operating at a resonance frequency of 110 Hz, under an acoustic pressure of 144.2 dBspc, the maximum open-circuit voltage and short-circuit current of the generator can respectively reach 65 V and 32 ~A underwater. The directional dependence pattern has a bi-directional shape with a total response angle of 60~. Its sensitivity is higher than -185 dB in the frequency range from 30 Hz to 200 Hz. The highest sensitivity is -146 dB at resonance frequency. The three-dimensional coordinates of an acoustic source were identified by four TENGs, self-powered active sensors, and the location of the acoustic source was determined with an error about 0.2 m. This study not only expands the application fields of TENGs from the atmosphere to water, but also shows the TENG is a promising acoustic source locator in underwater environments.展开更多
In recent years, triboelectric nanogenerators have attracted much attention because of their unique potential in self-powered nanosensors and nanosystems. In this paper, we report a cylindrical spiral tdboelectric nan...In recent years, triboelectric nanogenerators have attracted much attention because of their unique potential in self-powered nanosensors and nanosystems. In this paper, we report a cylindrical spiral tdboelectric nanogenerator （S-TENG）, which not only can produce high electric output to power display devices, but also can be used as a self-powered displacement sensor integrated on a measurement ruler. At a sliding speed of 2.5 m/s, S-TENG can generate a short-circuit current （Isc） of 30 μA and an open-circuit voltage （Voc） of 40 V. As the power source, we fabricate a transparent and flexible hand-driven S-TENG. Furthermore, we demonstrate a self-powered S-TENG-based measuring tapeline that can accurately measure and display the pulled-out distance without the need for an extra battery. The results obtained indicate that TENG-based devices have good potential for application in self-powered measurement systems.展开更多
Scavenging vibration energy directly from environments is an attractive technique for potentially powering small and/or wireless electronic devices in a smart structure and system.In this paper,a novel broadband vibra...Scavenging vibration energy directly from environments is an attractive technique for potentially powering small and/or wireless electronic devices in a smart structure and system.In this paper,a novel broadband vibration energy harvester is designed and analyzed,which consists of three cantilever beams,two magnetoelectric(ME) transducers and a magnetic circuit.A theoretical model is developed to analyze the effects of the structure parameters on the frequency response and the electrical output for achieving the optimal vibration energy harvesting performances.A prototype is fabricated and tested.The experimental results show that the harvester has a bandwidth of 7.2 Hz and an average power of 0.21 mW at an acceleration of 0.2 g(with g=9.8 ms-2).展开更多
文摘太阳能供电的传感器节点在电池充满电时会产生过剩的能量,如不加以利用会被浪费。提出一种基于太阳能约束的可靠数据传输方法 RDDMSC(Reliable Data Delivery Method based on Solar Constraint),利用过剩的能量自适应地调整通信中纠错码的冗余度,在网络寿命保持不变的情况下提高传输的可靠性。将问题描述为在有能量约束时最大限度地保证端到端数据包的传输率。证明了在链路质量不差的情况下目标函数一定是凹函数,进而采用凸优化来解决可靠传输问题。实验结果表明,RDDMSC能够有效地使用过剩能量来能够提高数据传输率。
文摘A novel cement matrix smart piezoelectric composite and its application as sensing element are presented.A cement matrix smart piezoelectric composite piece encapsulated in a cement mortar formed a practical sensor, and it was tested on material test system with cyclic loading.According to the theoretical analysis, the function of the cement matrix piezoelectric sensor output voltage was expressed in terms of the magnitude of the input cyclic loading amplitude and frequency.The curve fitting of gain function that is defined as sensor′s gain factor under different frequencies of input loading was carried out. From the results of curve fitting, it is found that the cement matrix smart piezoelectric composite has a simple relationship between input loading and output voltage.Therefore the cement matrix piezoelectric composite sensor is suitable to be applied in structural health monitoring.
基金supported by the National Natural Science Foundation of China (11674048)the Fundamental Research Funds for the Central Universities (N170505001 and N160502002)the Program for Shenyang Youth Science and Technology Innovation Talents (RC170269)
文摘A new self-powered active gas sensor for realtime monitoring of automotive exhaust gas was devised.The pipe-shaped device was fabricated from polydimethylsiloxane/polypyrrole(PDMS/Ppy)triboelectric gas-sensing unit arrays.The gas-sensing units can actively convert the mechanical energy of gas flow into a triboelectric current.The output current signal depends on the species and concentrations of the target chemical gases(CO,NH3,NO)in the gas flow,and thus can be used as a sensing signal.The device consists of seven gas-sensing units with different Ppy derivatives.As the different sensing units respond to the gases in different ways,the device can differentiate between gas species.The working mechanism is attributed to the coupling effect between the triboelectric effect of PDMS/Ppy and the gas-sensing properties of Ppy.The device can be installed in the tailpipe of an automobile,and can thus analyze the exhaust gas in real time without the need for any external electrical power.The results of the present study spur a new research direction for the development of automotive exhaust gas monitoring systems,thus playing an important role in the detection of air pollution.
基金supported by the National Natural Science Foundation of China(Grant Nos.61176103,91323304)the National High-Tech Research and Development Program of China("863"Project)(Grant No.2013AA041102)the Beijing Natural Science Foundation of China(Grant No.4141002)
文摘Recently, triboelectric generator(TEG) has attracted a lot of attention due to its high output voltage and low-cost fabrication process. Here, a novel cubic TEG box is designed, which has separated electrodes on different surfaces. Thanks to the specially designed structure, it can scavenge vibration energy from all directions. Firstly the device is investigated through finite element method(FEM) simulation. Then the device is evaluated by experiments. The measuremental results show that this device can generate an amount of 25 n C charge during once shake by charging a 10 n F capacitor. Besides, an output voltage about 100 V is obtained, which is able to directly light up several light-emitting diodes(LEDs) simultaneously. At last, the device is utilized as a self-powered orientation sensor, which shows explicit directivity. This work extends the applications of TEG for ambient vibration energy harvesting techniques and the self-powered orientation sensor.
文摘Detecting/sensing targets underwater has very important applications in environmental study, civil engineering and national security. In this paper, an organic-film based triboelectric nanogenerator （TENG） has been successfully demonstrated for the first time as a self-powered and high sensitivity acoustic sensor to detect underwater targets at low frequencies around 100 Hz. This innovative, cost-effective, simple-design TENG consists of a thin-film-based Cu electrode and a polytetrafluoroethylene （PTFE） film with nanostructures on its surfaces. On the basis of the coupling effect between triboelectrification and electrostatic induction, the sensor generates electrical output signals in response to incident sound waves. Operating at a resonance frequency of 110 Hz, under an acoustic pressure of 144.2 dBspc, the maximum open-circuit voltage and short-circuit current of the generator can respectively reach 65 V and 32 ~A underwater. The directional dependence pattern has a bi-directional shape with a total response angle of 60~. Its sensitivity is higher than -185 dB in the frequency range from 30 Hz to 200 Hz. The highest sensitivity is -146 dB at resonance frequency. The three-dimensional coordinates of an acoustic source were identified by four TENGs, self-powered active sensors, and the location of the acoustic source was determined with an error about 0.2 m. This study not only expands the application fields of TENGs from the atmosphere to water, but also shows the TENG is a promising acoustic source locator in underwater environments.
基金Acknowledgements Thanks for the support from the ＂thousands talents＂ program for pioneer researcher and his innovation team, China, National Natural Science Foundation of China （Nos. 51432005 and 61405131）, Beijing Natural Science Foundation （No. 4154090）, Beijing City Committee of science and technology （Nos. Z131100006013004 and Z131100006013005）.
文摘In recent years, triboelectric nanogenerators have attracted much attention because of their unique potential in self-powered nanosensors and nanosystems. In this paper, we report a cylindrical spiral tdboelectric nanogenerator （S-TENG）, which not only can produce high electric output to power display devices, but also can be used as a self-powered displacement sensor integrated on a measurement ruler. At a sliding speed of 2.5 m/s, S-TENG can generate a short-circuit current （Isc） of 30 μA and an open-circuit voltage （Voc） of 40 V. As the power source, we fabricate a transparent and flexible hand-driven S-TENG. Furthermore, we demonstrate a self-powered S-TENG-based measuring tapeline that can accurately measure and display the pulled-out distance without the need for an extra battery. The results obtained indicate that TENG-based devices have good potential for application in self-powered measurement systems.
基金supported by the National Natural Science Foundation of China (No 50830202)
文摘Scavenging vibration energy directly from environments is an attractive technique for potentially powering small and/or wireless electronic devices in a smart structure and system.In this paper,a novel broadband vibration energy harvester is designed and analyzed,which consists of three cantilever beams,two magnetoelectric(ME) transducers and a magnetic circuit.A theoretical model is developed to analyze the effects of the structure parameters on the frequency response and the electrical output for achieving the optimal vibration energy harvesting performances.A prototype is fabricated and tested.The experimental results show that the harvester has a bandwidth of 7.2 Hz and an average power of 0.21 mW at an acceleration of 0.2 g(with g=9.8 ms-2).
