Electronic Textiles (e-textiles) are fabrics that feature electronics and interconnections woven into them, presenting physical flexibility and typical size that cannot be achieved with other existing electronic manufacturing techniques. Components and interconnections are intrinsic to the fabric and thus are less visible and not susceptible of becoming tangled or snagged by surrounding objects. E-textiles can also more easily adapt to fast changes in the computational and sensing requirements of any specific application, this one representing a useful feature for power management and context awareness. The vision behind wearable computing foresees future electronic systems to be an integral part of our everyday outfits. Such electronic devices have to meet special requirements concerning wearability. Wearable systems will be characterized by their ability to automatically recognize the activity and the behavioral status of their own user as well as of the situation around her/him, and to use this information to adjust the systems' configuration and functionality. This review focuses on recent advances in the field of Smart Textiles and pays particular attention to the materials and their manufacturing process. Each technique shows advantages and disadvantages and our aim is to highlight a possible trade-off between flexibility, ergonomics, low power consumption, integration and eventually autonomy.

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Wearable Electronics and Smart Textiles: A Critical Review

Dielectric polymer nanocomposites are rapidly emerging as novel materials for a number of advanced engineering applications. In this Review, we present a comprehensive review of the use of ferroelectric polymers, especially PVDF and PVDF-based copolymers/blends as potential components in dielectric nanocomposite materials for high energy density capacitor applications. Various parameters like dielectric constant, dielectric loss, breakdown strength, energy density, and flexibility of the polymer nanocomposites have been thoroughly investigated. Fillers with different shapes have been found to cause significant variation in the physical and electrical properties. Generally, one-dimensional and two-dimensional nanofillers with large aspect ratios provide enhanced flexibility versus zero-dimensional fillers. Surface modification of nanomaterials as well as polymers adds flavor to the dielectric properties of the resulting nanocomposites. Nowadays, three-phase nanocomposites with either combination of fillers...

Recent Progress on Ferroelectric Polymer-Based Nanocomposites for High Energy Density Capacitors: Synthesis, Dielectric Properties, and Future Aspects.

This paper reviews energy harvesting technology from mechanical vibration. Recent advances on ultralow power portable electronic devices and wireless sensor network require limitless battery life for better performance. People searched for permanent portable power sources for advanced electronic devices. Energy is everywhere around us and the most important part in energy harvesting is energy transducer. Piezoelectric materials have high energy conversion ability from mechanical vibration. A great amount of researches have been conducted to develop simple and efficient energy harvesting devices from vibration by using piezoelectric materials. Representative piezoelectric materials can be categorized into piezoceramics and piezopolymers. This paper reviews key ideas and performances of the reported piezoelectric energy harvesting from vibration. Various types of vibration devices, piezoelectric materials and mathematical modeling of vibrational energy harvestings are reviewed.

A Review of Piezoelectric Energy Harvesting Based on Vibration

This review provides a detailed overview of the energy harvesting technologies associated with piezoelectric materials along with the closely related sub-classes of pyroelectrics and ferroelectrics. These properties are, in many cases, present in the same material, providing the intriguing prospect of a material that can harvest energy from multiple sources including vibration, thermal fluctuations and light. Piezoelectric materials are initially discussed in the context of harvesting mechanical energy from vibrations using inertial energy harvesting, which relies on the resistance of a mass to acceleration, and kinematic energy harvesting which directly couples the energy harvester to the relative movement of different parts of a source. Issues related to mode of operation, loss mechanisms and using non-linearity to enhance the operating frequency range are described along with the potential materials that could be employed for harvesting vibrations at elevated temperatures. In addition to inorganic piezoelectric materials, compliant piezoelectric materials are also discussed. Piezoelectric energy harvesting devices are complex multi-physics systems requiring advanced methodologies to maximise their performance. The research effort to develop optimisation methods for complex piezoelectric energy harvesters is then reviewed. The use of ferroelectric or multi-ferroic materials to convert light into chemical or electrical energy is then described in applications where the internal electric field can prevent electron–hole recombination or enhance chemical reactions at the ferroelectric surface. Finally, pyroelectric harvesting generates power from temperature fluctuations and this review covers the modes of pyroelectric harvesting such as simple resistive loading and Olsen cycles. Nano-scale pyroelectric systems and novel micro-electro-mechanical-systems designed to increase the operating frequency are discussed.

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Piezoelectric and ferroelectric materials and structures for energy harvesting applications

Energy harvesting technologies that are engineered to miniature sizes, while still increasing the power delivered to wireless electronics,(1, 2) portable devices, stretchable electronics,(3) and implantable biosensors,(4, 5) are strongly desired. Piezoelectric nanowire- and nanofiber-based generators have potential uses for powering such devices through a conversion of mechanical energy into electrical energy.(6) However, the piezoelectric voltage constant of the semiconductor piezoelectric nanowires in the recently reported piezoelectric nanogenerators(7-12) is lower than that of lead zirconate titanate (PZT) nanomaterials. Here we report a piezoelectric nanogenerator based on PZT nanofibers. The PZT nanofibers, with a diameter and length of approximately 60 nm and 500 μm, were aligned on interdigitated electrodes of platinum fine wires and packaged using a soft polymer on a silicon substrate. The measured output voltage and power under periodic stress application to the soft polymer was 1.63 V and 0.03 ...

1.6 V Nanogenerator for Mechanical Energy Harvesting Using PZT Nanofibers

Rapid technological advances in nanotechnology, microelectronic sensors and systems are becoming increasingly miniaturized to the point where embedded wearable applications are beginning to emerge. A restriction to the widespread application of these microsystems is the power supply of relatively sizable dimensions, weight, and limited lifespan. Emerging micropower sources exploit self-powered generators utilizing the intrinsic energy conversion characteristics of smart materials. 'Energy harvesting' describes the process by which energy is extracted from the environment, converted and stored. Piezoelectric materials have been used to convert mechanical into electrical energy through their inherent piezoelectric effect. This paper focuses on the development of a micropower generator using microcomposite based piezoelectric materials for energy reclamation in glove structures. Devices consist of piezoelectric fibres, 90–250 µm in diameter, aligned in a unidirectional manner and incorporated into a composite structure. The fibres are laid within a single laminate structure with copper interdigitated electrodes assembled on both sides, forming a thin film device. Performances of devices with different fibre diameters and material thicknesses are investigated. Experiments are outlined that detail the performance characteristics of such piezoelectric fibre laminates. Results presented show voltage outputs up to 6 V which is considered enough for potential applications in powering wearable microsystems.

http://iopscience.iop.org/article/10.1088/0964-1726/17/2/025017/pdf

A piezoelectric fibre composite based energy harvesting device for potential wearable applications

Self-piercing riveting (SPR) is a cold mechanical joining process used to join two or more sheets of materials by driving a rivet piercing through the top sheet or the top and middle sheets and subsequently lock into the bottom sheet under the guidance of a suitable die. SPR is currently the main joining method for aluminium and mixed-material lightweight automotive structures. SPR was originated half century ago, but it only had significant progress in the last 25 years due to the requirement of joining lightweight materials, such as aluminium alloy structures, aluminium-steel structures and other mixed-material structures, from the automotive industry. Compared with other conventional joining methods, SPR has many advantages including no pre-drilled holes required, no fume, no spark and low noise, no surface treatment required, ability to join multi-layer materials and mixed materials and ability to produce joints with high static and fatigue strengths. In this paper, research investigations that have been conducted on self-piercing riveting will be extensively reviewed. The current state and development of SPR process is reviewed and the influence of the key process parameters on joint quality is discussed. The mechanical properties of SPR joints, the corrosion behaviour of SPR joints, the distortion of SPR joints and the simulation of SPR process and joint performance are reviewed. Developing reliable simulation methods for SPR process and joint performance to reduce the need of physical testing has been identified as one of the main challenges.

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Self-piercing riveting-a review

Piezoelectric smart polymer and ceramic materials can be deployed as a mechanism to transform mechanical energy into electrical energy that can be stored and used to power portable devices. This paper focuses on the development and comparison of a micropower based harvesting generator using piezoelectric PZT (lead zirconate titanate) ceramic, PVDF (polyvinylidene fluoride) membrane and PP (polypropylene) foam polymer with the intention of establishing power output from temperature fluctuations. Unimorph and bimorph strips of various sizes were prepared and subjected to vibration and impact experiments in order to directly compare the voltage output. The effect of the ceramic fibre diameter, laminate thickness, impact area, weight of the free falling mass, vibration frequency and temperature on the voltage output were studied. Experiments are outlined detailing the performance characteristics of such piezoelectric fibre laminates. Results show voltage outputs of nearly 40 V which is considered sufficient for potential applications in powering microsystems.

Utilisation of smart polymers and ceramic based piezoelectric materials for scavenging wasted energy

Mechanical behaviour of chicken quills and chicken feather fibres reinforced polymeric composites

In 2008, total worldwide energy consumption was 474 exajoules (474×1018 J) with 80 to 90 percent derived from fossil fuels(1). This is equivalent to an average power consumption rate of 15 terawatts (1.504×1013 W). Most of the world's energy resources are from the sun's rays hitting Earth. Some of that energy has been preserved as fossil energy; some are directly or indirectly usable, for example via wind, hydroor wave power. The term solar constant is the amount of incoming solar electromagnetic radiation per unit area, measured on the outer surface of Earth's atmosphere, in a plane perpendicular to the rays. The solar constant includes all types of solar radiation, not just visible light. The estimates of remaining non-renewable worldwide energy resources vary, with the remaining fossil fuels totalling an estimated 0.4YJ (1YJ = 1024J) and the available nuclear fuel such as uranium exceeding 2.5YJ. Fossil fuels range from 0.6-3YJ if estimates of reserves of methane are accurate and become technically extractable. The twentieth century saw a rapid twenty-fold increase in the use of fossil fuels. Between 1980 and 2006, the worldwide annual growth rate was 2%(1). According to the US Energy Information Administration's 2006, the estimated 471.8EJ total consumption in 2004 was divided as follows, with fossil fuels supplying 86% of the world's energy, see Figure 1. Coal fuelled the industrial revolution in the 18th and 19th century. With the advent of the automobile, airplanes and the spreading use of electricity, oil became the dominant fuel during the twentieth century. The growth of oil as the largest fossil fuel was further enabled by steadily dropping prices from 1920 until 1973.

/pdf/ceramic-based-intelligent-piezoelectric-energy-harvesting-43rags37wq.pdf

I. Patel

Papers

A piezoelectric fibre composite based energy harvesting device for potential wearable applications

Self-piercing riveting-a review

Utilisation of smart polymers and ceramic based piezoelectric materials for scavenging wasted energy

Mechanical behaviour of chicken quills and chicken feather fibres reinforced polymeric composites

Ceramic Based Intelligent Piezoelectric Energy Harvesting Device