Torsional vibration of a circular piezoelectric shell of polarized ceramics mounted on a rotationally vibrating base is analyzed. The shell is properly electroded and connected to a circuit such that an electric outpu...Torsional vibration of a circular piezoelectric shell of polarized ceramics mounted on a rotationally vibrating base is analyzed. The shell is properly electroded and connected to a circuit such that an electric output is generated. The structure analyzed represents a piezoelectric generator for converting mechanical energy from angular vibrations to electrical energy. Analytical expressions and numerical results for the output voltage, current, power, efficiency and power density are given.展开更多
The nonlinear behaviors of a circular-cylinder piezoelectric power harvester （CCPPH） near resonance are analyzed based on the flow-induced flexural vibration mode. The geometrically-nonlinear effect of the cylinder ...The nonlinear behaviors of a circular-cylinder piezoelectric power harvester （CCPPH） near resonance are analyzed based on the flow-induced flexural vibration mode. The geometrically-nonlinear effect of the cylinder is studied with considering the in-plane extension incidental to the large defection. The boundary electric charges generated from two deformation modes, flexure and in-plane extension, were distinguished with each other because the charge corresponding to the latter mode produces no contribution to the output current. Numerical results on output powers show that there are multi- valuedness and jump behaviors.展开更多
A structure consisting of a spiral piezoelectric transducer and a concentrated mass is proposed as a low-frequency piezoelectric power harvester. A theoretical model is developed for the system from the theory of piez...A structure consisting of a spiral piezoelectric transducer and a concentrated mass is proposed as a low-frequency piezoelectric power harvester. A theoretical model is developed for the system from the theory of piezoelectricity. An analysis is performed to demonstrate the low-frequency nature of the system. Other basic characteristics of the power harvester including the output power, voltage, and efficiency are also calculated and examined.展开更多
The shallow cylindrical structure is suitable to develop broadband vibration energy harvesters due to the property of the inherent mechanical bistability. In this letter, the optimum design of the bistable cylindrical...The shallow cylindrical structure is suitable to develop broadband vibration energy harvesters due to the property of the inherent mechanical bistability. In this letter, the optimum design of the bistable cylindrical shell for broadband energy harvesting application is investigated from the structural point of view. The output power is evaluated by the concept of the harvestable power, which balances the frequency of snap through and the referred output energy associated with each snap through. The non- dimensional harvestable power is analytically expressed as the function of the non-dimensional curvature parameter and one constructed parameter. The universal dependence of the optimal curvature parameter and the associated optimal harvestable power on the constructed parameter is derived, which can be well aooroximated by the linear relation in double logarithmic coordinate.展开更多
This paper presents an 8-bit sub-threshold microprocessor which can be powered by an integrated photosensitive diode.With a custom designed sub-threshold standard cell library and 1 kbit sub-threshold SRAM design, the...This paper presents an 8-bit sub-threshold microprocessor which can be powered by an integrated photosensitive diode.With a custom designed sub-threshold standard cell library and 1 kbit sub-threshold SRAM design, the leakage power of 58 nW,dynamic power of 385 nW @ 165 kHz,EDP 13 pJ/inst and the operating voltage of 350 mV are achieved.Under a light of about 150 kLux,the microprocessor can run at a rate of up to 500 kHz.The microprocessor can be used for wireless-sensor-network nodes展开更多
We propose a spiral-shaped piezoelectric bimorph power harvester operating with coupled flexural and extensional vibration modes for applications to low frequency energy sources. A theoretical analysis is performed an...We propose a spiral-shaped piezoelectric bimorph power harvester operating with coupled flexural and extensional vibration modes for applications to low frequency energy sources. A theoretical analysis is performed and the computational results show that the spiral structure has relatively low operating frequency compared to beam power harvesters of the same size. It is found that to optimize the performance of a piezoelectric spiral-shaped harvester careful design is needed.展开更多
A type of electromagnetic hip-mounted generator （EHG） is proposed to harvest energy from human hip motion to generate electricity. Based on the law of electromagnetic induction, the EHG generator can convert the kin...A type of electromagnetic hip-mounted generator （EHG） is proposed to harvest energy from human hip motion to generate electricity. Based on the law of electromagnetic induction, the EHG generator can convert the kinetic power of the thigh swing into electrical energy during walking or running. To demonstrate the feasibility of the present method, a prototype of the EHG has been designed and fabricated. A theoretical analysis has been conducted to interpret the working behavior of this prototype. In addition, the performance of the system has been experimentally tested through a rotary motor and human body motion. When driven by the rotary motor at a rotation speed of 100 r/rain, the open-circuit voltage of this prototype is 2.5 V. Further, a maximum open-circuit voltage of approximately 1 V and a maximum output power of 284 μW could be produced respectively when walking with an EHG at a speed of 1.47 m/s. This handy renewable energy technology is promising as a pervasive electricity generation system for a group of wearable or implanted sensors, actuators and mobile electronics.展开更多
文摘Torsional vibration of a circular piezoelectric shell of polarized ceramics mounted on a rotationally vibrating base is analyzed. The shell is properly electroded and connected to a circuit such that an electric output is generated. The structure analyzed represents a piezoelectric generator for converting mechanical energy from angular vibrations to electrical energy. Analytical expressions and numerical results for the output voltage, current, power, efficiency and power density are given.
基金supported by the National Natural Science Foundation of China(Nos.10932004 and11272127)a grant from the Impact and Safety of Coastal Engineering Initiative,a Center of Excellence Program of Zhejiang Provincial Government at Ningbo University(No.zj1213)
文摘The nonlinear behaviors of a circular-cylinder piezoelectric power harvester （CCPPH） near resonance are analyzed based on the flow-induced flexural vibration mode. The geometrically-nonlinear effect of the cylinder is studied with considering the in-plane extension incidental to the large defection. The boundary electric charges generated from two deformation modes, flexure and in-plane extension, were distinguished with each other because the charge corresponding to the latter mode produces no contribution to the output current. Numerical results on output powers show that there are multi- valuedness and jump behaviors.
基金supported by the National Natural Science Foundation of China(Nos.10932004 and 11272127)
文摘A structure consisting of a spiral piezoelectric transducer and a concentrated mass is proposed as a low-frequency piezoelectric power harvester. A theoretical model is developed for the system from the theory of piezoelectricity. An analysis is performed to demonstrate the low-frequency nature of the system. Other basic characteristics of the power harvester including the output power, voltage, and efficiency are also calculated and examined.
基金supported by the National Natural Science Foundation of China(11472240,11302064,and 11321202)the Fundamental Research Funds for the Central Universities(2014QNA4034)
文摘The shallow cylindrical structure is suitable to develop broadband vibration energy harvesters due to the property of the inherent mechanical bistability. In this letter, the optimum design of the bistable cylindrical shell for broadband energy harvesting application is investigated from the structural point of view. The output power is evaluated by the concept of the harvestable power, which balances the frequency of snap through and the referred output energy associated with each snap through. The non- dimensional harvestable power is analytically expressed as the function of the non-dimensional curvature parameter and one constructed parameter. The universal dependence of the optimal curvature parameter and the associated optimal harvestable power on the constructed parameter is derived, which can be well aooroximated by the linear relation in double logarithmic coordinate.
基金Project supported by the National Natural Science Foundation of China(No.60906010)
文摘This paper presents an 8-bit sub-threshold microprocessor which can be powered by an integrated photosensitive diode.With a custom designed sub-threshold standard cell library and 1 kbit sub-threshold SRAM design, the leakage power of 58 nW,dynamic power of 385 nW @ 165 kHz,EDP 13 pJ/inst and the operating voltage of 350 mV are achieved.Under a light of about 150 kLux,the microprocessor can run at a rate of up to 500 kHz.The microprocessor can be used for wireless-sensor-network nodes
基金This work was supported by the National Natural Science Foundation of China (Grant No.10172036)the Scientific Research Foundation for the Returned Overseas Chinese Scholar,Ministry of Education of China.
文摘We propose a spiral-shaped piezoelectric bimorph power harvester operating with coupled flexural and extensional vibration modes for applications to low frequency energy sources. A theoretical analysis is performed and the computational results show that the spiral structure has relatively low operating frequency compared to beam power harvesters of the same size. It is found that to optimize the performance of a piezoelectric spiral-shaped harvester careful design is needed.
文摘A type of electromagnetic hip-mounted generator （EHG） is proposed to harvest energy from human hip motion to generate electricity. Based on the law of electromagnetic induction, the EHG generator can convert the kinetic power of the thigh swing into electrical energy during walking or running. To demonstrate the feasibility of the present method, a prototype of the EHG has been designed and fabricated. A theoretical analysis has been conducted to interpret the working behavior of this prototype. In addition, the performance of the system has been experimentally tested through a rotary motor and human body motion. When driven by the rotary motor at a rotation speed of 100 r/rain, the open-circuit voltage of this prototype is 2.5 V. Further, a maximum open-circuit voltage of approximately 1 V and a maximum output power of 284 μW could be produced respectively when walking with an EHG at a speed of 1.47 m/s. This handy renewable energy technology is promising as a pervasive electricity generation system for a group of wearable or implanted sensors, actuators and mobile electronics.
