A Review of Piezoelectric Footwear Energy Harvesters: Principles, Methods, and Applications

Over the last couple of decades, numerous piezoelectric footwear energy harvesters (PFEHs) have been reported in the literature. This paper reviews the principles, methods, and applications of PFEH technologies. First, the popular piezoelectric materials used and their properties for PEEHs are summarized. Then, the force interaction with the ground and dynamic energy distribution on the footprint as well as accelerations are analyzed and summarized to provide the baseline, constraints, potential, and limitations for PFEH design. Furthermore, the energy flow from human walking to the usable energy by the PFEHs and the methods to improve the energy conversion efficiency are presented. The energy flow is divided into four processing steps: (i) how to capture mechanical energy into a deformed footwear, (ii) how to transfer the elastic energy from a deformed shoes into piezoelectric material, (iii) how to convert elastic deformation energy of piezoelectric materials to electrical energy in the piezoelectric structure, and (iv) how to deliver the generated electric energy in piezoelectric structure to external resistive loads or electrical circuits. Moreover, the major PFEH structures and working mechanisms on how the PFEHs capture mechanical energy and convert to electrical energy from human walking are summarized. Those piezoelectric structures for capturing mechanical energy from human walking are also reviewed and classified into four categories: flat plate, curved, cantilever, and flextensional structures. The fundamentals of piezoelectric energy harvesters, the configurations and mechanisms of the PFEHs, as well as the generated power, etc., are discussed and compared. The advantages and disadvantages of typical PFEHs are addressed. The power outputs of PFEHs vary in ranging from nanowatts to tens of milliwatts. Finally, applications and future perspectives are summarized and discussed

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

Development of Energy Generation By Using Peizoelectric Material Via Structural Vibration

The heart of this project is to find a way to use lost energies. In this case vibrations caused by machines or walking is a lost energy that need to be used. As low power electronics and wireless technology starts to develop recently, it was necessary to think of new power sources that produce low power and easily to be harvested. The harvesting of power from different sources started to become commonly used in the last years. With the time the power harvesting circuits will replace the normal finite power supplies used. Piezoelectric material technology produced a new way that uses some of the energy being wasted or ignored in the surrounding, in this case vibration energy that usually lost. Theses materials is already put in to use to harvest power; however, the power produced by these material is very small to be able to power most electronic systems. The research made into this matter has always ended up with the need for methods to accumulate the produced power until an amount of enough energy is produced. At the end of this project the outcome should be a stable source of power to charge a mobile battery or a power ban

Energy harvesting applied to smart shoes

The appeal of energy harvesting systems lies in the possibility of capturing free energy that would be dissipated and is therefore obtainable without costs. Today, advanced techniques and devices exist for capturing from the environment, storing, and managing quotas of natural energy, which are made available in the form of electrical energy. At the same time, the most recent microprocessors grant an extremely high power efficiency, which permits their operation with minimal power consumption. As a consequence, low-consuming devices can be power supplied by using energy harvesting systems. If this concept is applied to wearable electronics, the most efficient choice is that of exploiting the energy released when the users walk, by developing systems that are embedded in the shoe sole. At each step, the force exerted on the device can be transformed into a relatively high amount of electrical energy, for example by using piezoelectric elements and electromagnetic induction systems. The paper describes the design of four different solutions for smart shoes that make use of energy harvesting apparatuses for the power supply of sensors and complex monitoring systems, for example aimed at GPS localization. An initial comparative assessment of the four architectures is reported, by weighing production costs, ease of manufacture and energy harvesting performance

Development of Piezoelectric Nano- generator with Super-Capacitor

Harvesting mechanical energy from human motion is an attractive approach for obtaining clean and sustainable electric energy to power wearable sensors, which are widely used for health monitoring, activity recognition, gait analysis and so on. This paper studies a piezoelectric energy based device which conserve mechanical energy in shoes originated from human motion. The device is based on a on a pressure based energy generation. Besides, consideration is given to both high performance durability and build with repect to keeping the comfort in mind . The device provides an average output power of 1 mW during a walk at a frequency of roughly 1 Hz., a direct current (DC) power supply is built through integrating the device with a power management circuit

Development of a self-powered piezo-resistive smart insole equipped with low-power BLE connectivity for remote gait monitoring

The evolution of low power electronics and the availability of new smart materials are opening new frontiers to develop wearable systems for medical applications, lifestyle monitoring, and performance detection. This paper presents the development and realization of a novel smart insole for monitoring the plantar pressure distribution and gait parameters; indeed, it includes a piezoresistive sensing matrix based on a Velostat layer for transducing applied pressure into an electric signal. At first, an accurate and complete characterization of Velostat-based pressure sensors is reported as a function of sizes, support material, and pressure trend. The realization and testing of a low-cost and reliable piezoresistive sensing matrix based on a sandwich structure are discussed. This last is interfaced with a low power conditioning and processing section based on an Arduino Lilypad board and an analog multiplexer for acquiring the pressure data. The insole includes a 3- axis capacitive accelerometer for detecting the gait parameters (swing time and stance phase time) featuring the walking. A Bluetooth Low Energy (BLE) 5.0 module is included for transmitting in real-time the acquired data toward a PC, tablet or smartphone, for displaying and processing them using a custom Processing® application. Moreover, the smart insole is equipped with a piezoelectric harvesting section for scavenging energy from walking. The onfield tests indicate that for a walking speed higher than 1 ms−1, the device’s power requirements (i.e., P = 5.84 mW ) was fulfilled. However, more than 9 days of autonomy are guaranteed by the integrated 380-mAh Lipo battery in the total absence of energy contributions from the harvesting section

Energy Harvesting on Footsteps Using Piezoelectric based on Circuit LCT3588 and Boost up Converter

Piezoelectric utilization as a generator is an effort to obtain electrical energy that refers to the concept of energy harvesting referring the development of piezoelectric as a generator that converts the pressure or vibration generated from steps into electrical energy that can be used on low-power electronic devices. Because the use of piezoelectric as a generator allows the use in charging low voltage, a larger resource is required in different series. Based on the problem, an energy harvesting device and a voltage amplifier are created to increase the voltage of the pizoelectric output. An arduino microcontroller is used to control the energy harvesting device and voltage booster. It is required approximately 10 steps to charge four AA 1.2 Volt batteries and 80 steps to charge two 12 volt batteries respectively

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

Getting Fit in a Sustainable Way: Design and Optimization of a Low-Cost Regenerative Exercise Bicycle

With the increase in demand for more sustainable energy sources, recent researchers have been looking into harvesting energy spent by humans for various purposes. One of the available sources of such energy is exercise equipment. While a few products are available in the market to harvest the power expended during an exercise session, these products are costly, and the cost may prohibit a day-to-day user from purchasing those. Motivated by this challenge, this paper describes a long-running research project that uses a static exercise bicycle to sustainably harvest human energy. A regenerative spin bike that uses the friction between a flywheel and a BaneBots wheel was designed and deployed. For the motor mount, two methods are investigated: linear preloading and rotary preloading. A commercially available indoor static bicycle is modified to incorporate the flywheel and the motor attachment. The generated electricity is converted to DC using a three-phase rectifier. A car charger is used for charging any devices attached to the setup. The resulting configuration is very effective in operating small electronic devices. This setup, which uses only off-theshelf components, can be considered a replacement for its expensive custom-made counterparts