One of the new methods for powering low-power electronic devices at sea is a wave energy harvesting system. In this method, piezoelectric material is employed to convert the mechanical energy of sea waves into electri...One of the new methods for powering low-power electronic devices at sea is a wave energy harvesting system. In this method, piezoelectric material is employed to convert the mechanical energy of sea waves into electrical energy. The advantage of this method is based on avoiding a battery charging system. Studies have been done on energy harvesting from sea waves, however, considering energy harvesting with random JONSWAP wave theory, then determining the optimum values of energy harvested is new. This paper does that by implementing the JONSWAP wave model, calculating produced power, and realistically showing that output power is decreased in comparison with the more simple Airy wave model. In addition, parameters of the energy harvester system are optimized using a simulated annealing algorithm, yielding increased produced power.展开更多
Due to their particular optical characteristics,metallic island films have the potential to significantly increase the energy conversion efficiency of solar cell.We experimentally and theoretically investigated the ef...Due to their particular optical characteristics,metallic island films have the potential to significantly increase the energy conversion efficiency of solar cell.We experimentally and theoretically investigated the effect of substrate temperature on the morphologies and optical properties of the silver island films.At low temperature,below 300 ℃,as the substrate temperature increases.Compared to the films prepared at room temperature,the sizes of nanoparticles decrease and the Absorption peaks shift to shorter wavelength accompanied by an increase density resulting in a 150% Absorption efficiency.As the substrate temperature goes up to 300 ℃,nanoparticles with larger in-plan(X-Y)dimensions are formed,the number density decreases and the Absorption peaks redshift but the Absorption efficiency is still 10% higher.Numerical simulation reveals that these behaviors are a consequence of morphologies transformation.展开更多
This paper evaluates new technologies for energy harvesting from the environment. We assess the reliability, accuracy, and autonomy of low power electronic devices, their market opportunities, and their ability to enh...This paper evaluates new technologies for energy harvesting from the environment. We assess the reliability, accuracy, and autonomy of low power electronic devices, their market opportunities, and their ability to enhance sustainable development. For small, portable applications that need long lifetime energy supply systems, size, width, finite energy lifetime, and the need for replacement are important drawbacks. New supply alternatives should be explored that are able to make recharging easier or to remove battery dependence altogether. A new trend in the energy sources for low power applications has emerged in recent years, involving the harvesting of the energy available in the environment to supply power for electronic applications instead of using battery technologies that provide only short, finite amounts of energy. In this paper, we describe an all-purpose module of energy harvesting from mechanical, thermal, solar and RF energy sources developed at the University of Barcelona. We provide proof of concept in order to incorporate this novel energy technology in a wide range of applications and environments.展开更多
With the increasing use of low voltage portable devices and wireless systems, energy harvesting has become an attractive approach to overcome the problems associated with battery life and power source. Among the diffe...With the increasing use of low voltage portable devices and wireless systems, energy harvesting has become an attractive approach to overcome the problems associated with battery life and power source. Among the different types of microenergy scavengers, the TEG （thermoelectric generators） are one of the most commonly used one. Unfortunately, due to the very small amount of voltage delivered by the TEG, an efficient DC/DC （direct current/direct current） conversion and power management techniques are needed. In this paper, a CMOS （complementary metal oxide semiconductor） fully-integrated DC/DC convener for energy harvesting applications is presented. The startup-voltage of the converter is about 140 mV, the output voltage exceeds 1.5 V, with a 20% power efficiency at least. The architecture for boosting such extremely low voltages is based on an ultra-low-voltage oscillator cross connected to two phase charge pump. The overall circuit does not require any external components and can be fully integrated in a standard CMOS low voltage technology. A test-chip has been designed in UMC （united microelectronics corporation） 180 nm CMOS process.展开更多
As the first invention to efficiently harvest electricity from ambient mechanical energy by using contact electrification, the triboelectric nanogenerator has elicited worldwide attention because of its cost-effective...As the first invention to efficiently harvest electricity from ambient mechanical energy by using contact electrification, the triboelectric nanogenerator has elicited worldwide attention because of its cost-effectiveness and sustainability. This study exploits a superhydrophobic nanostructured aluminum tube to estimate electrical output for solid-water contact electrification inside a tubular system. The linearly proportional relationship of short-circuit current and open-circuit voltage to the detaching speed of water was determined by using a theoretical energy harvesting model and experimentation. A pioneering stick-type solid-water interacting triboelectric nanogenerator, called a SWING stick, was developed to harvest mechanical energy through solid-water contact electrification generated when the device is shaken by hand. The electrical output generated by various kinds of water from the environment was also measured to demonstrate the concept of the SWING stick as a compact triboelectric nanogenerator. Several SWING sticks were connected to show the feasibility of the device as a portable and compact source of direct power. The developed energy harvesting model and the SWING stick can provide a guideline for the design parameters to attain a desired electrical output; therefore, this study can significantly increase the applicability of a water-driven triboelectric nanogenerator.展开更多
文摘One of the new methods for powering low-power electronic devices at sea is a wave energy harvesting system. In this method, piezoelectric material is employed to convert the mechanical energy of sea waves into electrical energy. The advantage of this method is based on avoiding a battery charging system. Studies have been done on energy harvesting from sea waves, however, considering energy harvesting with random JONSWAP wave theory, then determining the optimum values of energy harvested is new. This paper does that by implementing the JONSWAP wave model, calculating produced power, and realistically showing that output power is decreased in comparison with the more simple Airy wave model. In addition, parameters of the energy harvester system are optimized using a simulated annealing algorithm, yielding increased produced power.
基金The Distinguished Youth Foundation of Hunan Province(03JJY1008)The Natural Science Foundation of Hunan Province(06JJ2034)
文摘Due to their particular optical characteristics,metallic island films have the potential to significantly increase the energy conversion efficiency of solar cell.We experimentally and theoretically investigated the effect of substrate temperature on the morphologies and optical properties of the silver island films.At low temperature,below 300 ℃,as the substrate temperature increases.Compared to the films prepared at room temperature,the sizes of nanoparticles decrease and the Absorption peaks shift to shorter wavelength accompanied by an increase density resulting in a 150% Absorption efficiency.As the substrate temperature goes up to 300 ℃,nanoparticles with larger in-plan(X-Y)dimensions are formed,the number density decreases and the Absorption peaks redshift but the Absorption efficiency is still 10% higher.Numerical simulation reveals that these behaviors are a consequence of morphologies transformation.
文摘This paper evaluates new technologies for energy harvesting from the environment. We assess the reliability, accuracy, and autonomy of low power electronic devices, their market opportunities, and their ability to enhance sustainable development. For small, portable applications that need long lifetime energy supply systems, size, width, finite energy lifetime, and the need for replacement are important drawbacks. New supply alternatives should be explored that are able to make recharging easier or to remove battery dependence altogether. A new trend in the energy sources for low power applications has emerged in recent years, involving the harvesting of the energy available in the environment to supply power for electronic applications instead of using battery technologies that provide only short, finite amounts of energy. In this paper, we describe an all-purpose module of energy harvesting from mechanical, thermal, solar and RF energy sources developed at the University of Barcelona. We provide proof of concept in order to incorporate this novel energy technology in a wide range of applications and environments.
文摘With the increasing use of low voltage portable devices and wireless systems, energy harvesting has become an attractive approach to overcome the problems associated with battery life and power source. Among the different types of microenergy scavengers, the TEG （thermoelectric generators） are one of the most commonly used one. Unfortunately, due to the very small amount of voltage delivered by the TEG, an efficient DC/DC （direct current/direct current） conversion and power management techniques are needed. In this paper, a CMOS （complementary metal oxide semiconductor） fully-integrated DC/DC convener for energy harvesting applications is presented. The startup-voltage of the converter is about 140 mV, the output voltage exceeds 1.5 V, with a 20% power efficiency at least. The architecture for boosting such extremely low voltages is based on an ultra-low-voltage oscillator cross connected to two phase charge pump. The overall circuit does not require any external components and can be fully integrated in a standard CMOS low voltage technology. A test-chip has been designed in UMC （united microelectronics corporation） 180 nm CMOS process.
文摘As the first invention to efficiently harvest electricity from ambient mechanical energy by using contact electrification, the triboelectric nanogenerator has elicited worldwide attention because of its cost-effectiveness and sustainability. This study exploits a superhydrophobic nanostructured aluminum tube to estimate electrical output for solid-water contact electrification inside a tubular system. The linearly proportional relationship of short-circuit current and open-circuit voltage to the detaching speed of water was determined by using a theoretical energy harvesting model and experimentation. A pioneering stick-type solid-water interacting triboelectric nanogenerator, called a SWING stick, was developed to harvest mechanical energy through solid-water contact electrification generated when the device is shaken by hand. The electrical output generated by various kinds of water from the environment was also measured to demonstrate the concept of the SWING stick as a compact triboelectric nanogenerator. Several SWING sticks were connected to show the feasibility of the device as a portable and compact source of direct power. The developed energy harvesting model and the SWING stick can provide a guideline for the design parameters to attain a desired electrical output; therefore, this study can significantly increase the applicability of a water-driven triboelectric nanogenerator.
