Piezoelectric wind power harnessing – an overview

As fossil energy resources deplete, wind energy gains ever more importance. Recently, piezoelectric energy harvesting methods are emerging with the advancements in piezoelectric materials and its storage elements. Piezoelectric materials can be utilized to convert kinetic energy to electrical energy. Utilization of piezoelectric wind harvesting is a rather new means to convert renewable wind energy to electricity. Piezoelectric generators are typically low cost and easy to maintain. This work illustrates an overview of piezoelectric wind harvesting technology. In wind harvesting, piezoelectric material choice is of the first order of importance. Due to their strain rate, robustness is a concern. For optimum energy harvesting efficiency resonant frequency of the selected materials and overall system configuration plays important role. In this work, existing piezoelectric wind generators are grouped and presented in following categories: leaf type, rotary type, rotary to linear type and beam type wind generators

Design and experimental characterization of a tunable vibration-based electromagnetic micro-generator

Vibration-based micro-generators, as an alternative source of energy, have become increasingly significant in the last decade. This paper presents a new tunable electromagnetic vibration-based micro-generator. Frequency tuning is realized by applying an axial tensile force to the micro-generator. The dimensions of the generator, especially the dimensions of the coil and the air gap between magnets, have been optimized to maximize the output voltage and power of the micro-generator. The resonant frequency has been successfully tuned from 67.6 to 98 Hz when various axial tensile forces were applied to the structure. The generator produced a power of 61.6–156.6 µW over the tuning range when excited at vibrations of 0.59 ms-2. The tuning mechanism has little effect on the total damping. When the tuning force applied on the generator becomes larger than the generator’s inertial force, the total damping increases resulting in reduced output power. The resonant frequency increases less than indicated from simulation and approaches that of a straight tensioned cable when the force associated with the tension in the beam becomes much greater than the beam stiffness. The test results agree with the theoretical analysis presented

A Human Powered Micro-generator for Charging Electronic Devices

A hand-pulled generator has been designed and tested. A preliminary result has been obtained and discussed. This device was created to provide outlet-free charging. Electronic devices are useful when going out into the wilderness. A portable power supply is necessary to keep an electronic device alive. This project created a device that converts human energy into electricity to charge electronic devices. This thesis overviews the device’s design, build, and tests. Two different tests were run to determine that the device is capable of charging the storage battery. The device presented can provide 14 minutes of charging time with one hour of string pulling. It is concluded that this device can be beneficial to people with electronic devices that need off-grid charging

Design of a body energy harvesting system for the upper extremity

Converting energy from human upper limb motions into electrical energy is a challenge, as low frequency movements have to be converted into repetitive movements to effectively drive electromechanical generators. The prototype of an electromagnetic linear generator with gyrating mass is presented. The mechanical motion model first was simulated and the design was evaluated during different activities. An average power output of about 50 μW was determined with a maximum power output of 2.2 mW that is sufficient to operate sensors for health monitoring

Development and efficiency optimizing of the human body energy converters

Nowadays it is known that the human body is continuous source of many types of energy and the devices used for collecting energy taken from the environment also have the required capabilities for the collection of the energy produced by the Human body (HB), but very limited and with very low efficiency. Low power and high yield converters are particularly needed in these cases of collecting energy from human activity and its movements due to the small amount of energy generated this way. But this situation can be improved. Enhancing or focusing the human movements by using mechanical amplifiers applied to the piezoelectric element. By doing so the input of energy in the element increases. As such increasing its output, therefore producing more energy

Human movement energy harvesting : a non-linear electromagnetic approach

Energy harvesting is one of the methods that currently engage actively in energy “recycling”. Of the many energy sources that carry the potential to have energy harvested and recycled, humans are seen as a potential source of energy. High amounts of energy are wasted from daily activities that humans do, if only a portion of the wasted energy can be harvested and reused with the aim of improving the quality of life of the user.To do that, the accelerations of selected movements are recorded from sensors attached to four different locations of the body. Human movements operate on a low and wide frequency scale, nonlinear energy harvesting techniques is seen as a suitable technique to be applied. Nonlinear energy harvesting techniques are expected to increase the bandwidth of operation of the energy harvester. The electromagnetic method of transduction is also selected (using two opposing magnets) to be paired with the nonlinear energy harvesting techniques to evaluate the potential of energy harvesting from human movements. The pick-up coil to be used will be placed at a novel location within the energy harvester prototype.Through simulations and experiments, frequency responses obtained did show an increase in bandwidth which agrees with literature from nonlinear energy harvesting techniques. Phase portraits are also used to provide a more in depth understanding on the movements from the cantilever under linear and nonlinear dynamics. Result comparisons were made between the simulation model and the experimental prototype to verify the agreement between the two.Additionally, results obtained also showed that the resonant frequency of the system was reduced when operating under the nonlinear regime. These attribute favour energy harvesting though human movements.Finally, the novel placement of the pick-up coil within the nonlinear electromagnetic energy harvester had the desired effect. Similar power outputs were achieved even though the separation distances between the two opposing magnets were varied

Human Powered Energy Harvester based on Autowinder Mechanism: Analysis, Build and Test

Experts estimate that approximately one third of the worldwide population currently owns a smartphone, and subscriptions continue to grow. Compared to mobile devices of the past decade, smartphones provide desktop computer-level processing power in a palm-sized package. However, the high computing power and 24 hours - 7 days a week connectivity results in a shorter battery life, often forcing the user to rely on portable battery packs. Worldwide energy consumption statistics show that the electric power grid depends primarily on fossil fuels. Thus, a renewable power source based on human motion energy harvesting offers a potential solution to power portable communication devices and may help reduce dependence on the power grid. A novel wrist-worn energy-harvester, based on an automatic winding mechanism, was designed, fabricated and experimentally tested. The mechanism frequently employed in wrist and pocket watches dates back to the 18th century, and is one of the oldest examples of mobile human energy harvesting. In this project, the prototype device contains a rotary pendulum connected to a DC generator through a planetary gear train. An electronics module consisting of a rectifier and boost converter filters the generator output, supplying regulated DC output to charge a battery, and/or power an electrical load. An onboard microcontroller broadcasts the voltage, current, and power data wirelessly for data collection during testing. Numerical and experimental validations were conducted for the energy harvester. A mathematical model for human arm swing dynamics was developed based on a triple pendulum system, and the device’s behavior was studied for both walking and running activities. The mechanical energy output from the rotary harvester pendulum was predicted to be 0.42 mJ and 2.06 mJ for simulated walking and running sequences over a period of 5 seconds (without load). A subsequent mathematical model was developed incorporating the electromechanical behavior of the generator and attached electronics module. A simulated running sequence with a representative electrical load yielded 1.72 mJ of electrical energy output over 5 seconds. The prototype was experimentally validated over the same conditions, resulting in an unregulated energy output of 1.39 mJ and a regulated energy output at 5 VDC of 1.16mJ for 5 seconds. Experimental testing successfully demonstrated the harvester’s potential as a mobile energy source for portable consumer electronics. Future steps shall focus on implementing efficient components for increased power output and designing for improved ergonomics

An investigation on energy harvesting from wrist for smart electronic devices

In this thesis energy harvested using the wrist movement of human arm is discussed. Human arm is constantly being used during our normal routine work, walking running or doing chores. These actions could be helpful in producing electricity. Previously research has been performed on the human body's ability to produce energy. Magnets have been utilized to design a device that harvests the energy using the wrist movement for electronic devices. The magnets were placed inside a 3-D printed tube and coils were wrapped the tube to convert the electromagnetic field into electricity. It can be worn to collect energy all day long. To determine the maximum performance throughout the arm movements, simulations were performed on software called COMSOL. The experiments were carried out by placing this device on the shaker and open circuit voltage was calculated with and without a resistor using an oscilloscope. The open circuit voltage generated at the least frequency of the shaker was 0.24 V and 0.064 V with resistance and without resistance, respectively. Different frequencies were applied to further measure the voltages. As batteries are constantly being needed to be replaced for the wearable electronic devices so, we developed the device which will continuously recharge them. This is a significant step towards future wearable electronics not requiring battery maintenance as it can charge the batteries as the wearer is normally doing their work in their routine.Bu tezde insan kolunun bilek hareketi kullanılarak elde edilen enerji ele alınmıştır. Normal rutin işlerimizde, yürürken, koşarken veya ev işleri yaparken insan kolu sürekli olarak kullanılmaktadır. Bu eylemler elektrik üretiminde yardımcı olabilir. Daha önce insan vücudunun enerji üretme yeteneği üzerine araştırmalar yapılmıştır. Bu çalışmada mıknatıslar, elektronik cihazlar için bilek hareketini kullanarak enerji toplayan bir cihaz tasarlamak için kullanıldı. Mıknatıslar, 3 boyutlu baskılı bir tüpün içine yerleştirildi ve elektromanyetik alanı elektriğe dönüştürmek için tüpe bobinler sarıldı. Bu cihaz gün boyu enerji toplamak için giyilebilir. Kol hareketleri boyunca maksimum performansı belirlemek için COMSOL adı verilen yazılım üzerinde simülasyonlar yapılmıştır. Bu cihaz çalkalayıcı üzerine yerleştirilerek deneyler yapılmış ve osiloskop kullanılarak dirençli ve dirençsiz açık gerilim voltajı hesaplanmıştır. Çalkalayıcının en düşük frekansında üretilen açık devre voltajı dirençli ve dirençsiz durum için sırasıyla 0,24 V ve 0,064 V olmuştur. Voltajları daha fazla ölçmek için farklı frekanslar uygulandı. Giyilebilir elektronik cihazlar için pillerin sürekli olarak değiştirilmesi gerekmektedir. Bu, pilleri şarj edebildiği için pil bakımı gerektirmeyen, geleceğin giyilebilir elektronik cihazlarına doğru önemli bir adımdır çünkü kullanıcı normal olarak rutin işlerini yaparken pilleri şarj edebilir.No sponso