Tsvetozar Tsanev; Mariya Aleksandrova; Boriana Tzaneva; Valentin Videkov
Abstract
This paper is devoted to the approach for nanostructuring piezoelectric materials to enhance their electrical signal producing ability from a small area of mechanical activation for potential application as energy harvesting. The geometrical structuring of the piezoelectric material leads to higher piezoelectric ...
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This paper is devoted to the approach for nanostructuring piezoelectric materials to enhance their electrical signal producing ability from a small area of mechanical activation for potential application as energy harvesting. The geometrical structuring of the piezoelectric material leads to higher piezoelectric voltage per unit volume in comparison with a non-structured thin film. Template properties of porous anodic aluminium oxide (AAO) allow this approach. AAO layers with a variety of pore diameters (from 80nm to 100nm) were produced without overheating degradation of the substrates. The thickness of the studied layer was 19 1µm. It was realized sputtering of potassium niobate deposition into AAO to a maximum penetration of piezoelectric material into the pores. The obtained final structure was observed by scanning electron microscopy and Energy Dispersive X-Ray spectroscopy. The registered piezoelectric effect reaches to 454 mV for the reanodized membrane with pores widening. In this work, we continue to explore and further development of our previous research for template-assisted growth in porous aluminium oxide.
Mariya Aleksandrova; Tatyana Ivanova; Sascha Koch; Frank Hamelmann; Daniela Karashanova; Kostadinka Gesheva
Abstract
Thin films of BaSrTiO3 (BST) were deposited by radio frequency (RF) sputtering with sputtering voltage varied between 0.5 and 0.7 kV. BaSrTiO3 films are investigated regarding their suitability for use in flexible energy harvesting devices. Analysis of the spectra and micrographs showed the piezoelectric ...
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Thin films of BaSrTiO3 (BST) were deposited by radio frequency (RF) sputtering with sputtering voltage varied between 0.5 and 0.7 kV. BaSrTiO3 films are investigated regarding their suitability for use in flexible energy harvesting devices. Analysis of the spectra and micrographs showed the piezoelectric features and the polycrystalline nature for the films grown at higher sputtering voltage. Meanwhile, the presence of an amorphous phase with a lack of characteristic bonds was found out for BaSrTiO3 films grown at the lower sputtering voltage. The electrical measurements of Al/BaSrTiO3/Al harvester on plastic substrate in the low-frequency range revealed superior piezoelectric voltage and 40% exceeding power density for the samples prepared at 0.7 kV as compared to the other thin films deposited at 0.5 kV. These results are achieved by simple architecture of single layer harvester with small size (0.4 cm 2 ) and small film thickness (0.5 µm), containing lead-free material. It was proved that the sputtered BaSrTiO3 films are suitable for thin film piezoelectric nanogenerators and their performance could be easily tuned by the sputtering voltage. Possible applications of the proposed element are low-frequency vibrational harvesting and a strain gauge.
Hanjun Ryu; Sang-Woo Kim
Abstract
Smart sensors and network systems are commonly referred to as Internet of Things (IoT) and are being used to realize a smart society. Although the development of low-power smart systems and large-capacity batteries is increasing the usage time of IoT devices, the time-limited capability of such systems ...
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Smart sensors and network systems are commonly referred to as Internet of Things (IoT) and are being used to realize a smart society. Although the development of low-power smart systems and large-capacity batteries is increasing the usage time of IoT devices, the time-limited capability of such systems reveals a need for self-powered sensors and systems for sustained IoT use. Mechanical energy is easily accessible from the environment to power sensors and systems. The triboelectric nanogenerator (TENG) converts mechanical energy into electric energy was first introduced in January 2012 by Wang et al., and we describe recent developments in the triboelectric properties of the polymers because the contact electrification between the two different materials is a key factor of TENG. This review article discusses the four operating modes of TENG, the working mechanism, the theoretical modelling of the vertical TENG, and the research aspects of the material.
Tomasz Blaszczyk; John Aa. Sørensen; Per Lynggaard; Kristian Larsen
Abstract
The rapidly growing demand for even more detailed low-cost measurements of weather and environmental conditions, including wind flow, asks for self-sustained energy solutions that eliminate the need for external recharge or replacement of batteries. Today’s wind measurement market is ...
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The rapidly growing demand for even more detailed low-cost measurements of weather and environmental conditions, including wind flow, asks for self-sustained energy solutions that eliminate the need for external recharge or replacement of batteries. Today’s wind measurement market is limited to traditional anemometers, ultrasonic measurement or expensive LIDAR (Light Imaging, Detection and Ranging) systems. This paper presents the initial design considerations for a low-cost combined air speed and wind direction sensor, which harvests energy to drive it and to power the wireless transmission of system configurations and measurements. An energy-budget for this transmission is included.
Krit Koyvanich; Pruittikorn Smithmaitrie; Nantankan Muensit
Abstract
This work proposes an energy harvester that captures the mechanical energy caused by water flow and converts into an electrical energy through the piezoelectric effect. A flexible piezo-film has been used as a transducer in the energy harvesting system and the kinetic energy of the water flow is produced ...
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This work proposes an energy harvester that captures the mechanical energy caused by water flow and converts into an electrical energy through the piezoelectric effect. A flexible piezo-film has been used as a transducer in the energy harvesting system and the kinetic energy of the water flow is produced by using the vortex induced vibration technique. When placing in water way the transducer is fluctuating in the vortex of the fluid flow, producing the kinetic energy of 44 mW at a low fluid velocity of 6.8 m/s and low frequency of 0.4 Hz. This configuration generates a corresponding open-circuit voltage of 6.6 mV at a matching load of 1 MW, leading to the maximum output power of 0.18 mW. An efficiency power conversion of the harvesting system was evaluated to be about 4.4 %. It is possible to use the proposed unit under gravitational force where there is a difference in the levels of the fluid no matter in water way or transporting parts such as petroleum pipes. However, rectifying the output voltage generated by the present micro generator is compulsory in order to feed small scale electronics and communication, for instance, wireless sensor networks. Furthermore, multiple arrays of the piezoelectric unit are also promising for delivering higher output power.
Seema Sharma
Abstract
Nanotechnology is one of the rapidly growing scientific disciplines due to its enormous potential in creating novel materials that have advanced applications. Electrospinning has been found to be a viable technique to produce materials in nanofiber form. Ferroelectric and/or piezoelectric materials in ...
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Nanotechnology is one of the rapidly growing scientific disciplines due to its enormous potential in creating novel materials that have advanced applications. Electrospinning has been found to be a viable technique to produce materials in nanofiber form. Ferroelectric and/or piezoelectric materials in nanofiber and/or nanowire form have been utilized for producing energy harvesting devices, high frequency transducers, implanted biosensors, vibration absorbers and composite force sensors, etc. An in-depth review of research activities on the development of ferroelectric nanofibers, fundamental understanding of the electrospinning process, and properties of nanostructured fibrous materials and their applications is provided in this article. A detailed account on the type of fibers that have been electrospun and their characteristics is also elaborated. It is hoped that the overview article will serve as a good reference tool for nanoscience researchers in ferroelectric materials.
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