Power consumption is forecast by the International Technology Roadmap of Semiconductors (ITRS) to pose long-term technical challenges for the semiconductor industry. The purpose of this paper is threefold: (1) to provide an overview of strategies for powering MEMS via non-regenerative and regenerative power supplies; (2) to review the fundamentals of piezoelectric energy harvesting, along with recent advancements, and (3) to discuss future trends and applications for piezoelectric energy harvesting technology. The paper concludes with a discussion of research needs that are critical for the enhancement of piezoelectric energy harvesting devices.

/pdf/powering-mems-portable-devices-a-review-of-non-regenerative-30r5zxggdp.pdf

Powering MEMS portable devices—a review of non-regenerative and regenerative power supply systems with special emphasis on piezoelectric energy harvesting systems

A review of recent research on mechanics of multifunctional composite materials and structures

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 paper presents a state-of-the-art review on a hot topic in the literature, i.e., vibration based energy harvesting techniques, including theory, modelling methods and the realizations of the piezoelectric, electromagnetic and electrostatic approaches. To minimize the requirement of external power source and maintenance for electric devices such as wireless sensor networks, the energy harvesting technique based on vibrations has been a dynamic field of studying interest over past years. One important limitation of existing energy harvesting techniques is that the power output performance is seriously subject to the resonant frequencies of ambient vibrations, which are often random and broadband. To solve this problem, researchers have concentrated on developing efficient energy harvesters by adopting new materials and optimising the harvesting devices. Particularly, among these approaches, different types of energy harvesters have been designed with consideration of nonlinear characteristics so that the frequency bandwidth for effective energy harvesting of energy harvesters can be broadened. This paper reviews three main and important vibration-to-electricity conversion mechanisms, their design theory or methods and potential applications in the literature. As one of important factors to estimate the power output performance, the energy conversion efficiency of different conversion mechanisms is also summarised. Finally, the challenging issues based on the existing methods and future requirement of energy harvesting are discussed.

A comprehensive review on vibration energy harvesting: Modelling and realization

This paper reviews possible strategies to increase the operational frequency range of vibration-based micro-generators. Most vibration-based micro-generators are spring-mass-damper systems which generate maximum power when the resonant frequency of the generator matches the frequency of the ambient vibration. Any difference between these two frequencies can result in a significant decrease in generated power. This is a fundamental limitation of resonant vibration generators which restricts their capability in real applications. Possible solutions include the periodic tuning of the resonant frequency of the generator so that it matches the frequency of the ambient vibration at all times or widening the bandwidth of the generator. Periodic tuning can be achieved using mechanical or electrical methods. Bandwidth widening can be achieved using a generator array, a mechanical stopper, non-linear (e.g. magnetic) springs or bi-stable structures. Tuning methods can be classified into intermittent tuning (power is consumed periodically to tune the device) and continuous tuning (the tuning mechanism is continuously powered). This paper presents a comprehensive review of the principles and operating strategies for increasing the operating frequency range of vibration-based micro-generators presented in the literature to date. The advantages and disadvantages of each strategy are evaluated and conclusions are drawn regarding the relevant merits of each approach.

/pdf/strategies-for-increasing-the-operating-frequency-range-of-cpsinzpt7h.pdf

Strategies for increasing the operating frequency range of vibration energy harvesters: a review

Over the past few decades the use of portable and wearable electronics has grown steadily These devices are becoming increasingly more powerful However, the gains that have been made in the device performance have resulted in the need for significantly higher power to operate the electronics This issue has been further complicated due to the stagnant growth of battery technology over the past decade In order to increase the life of these electronics, researchers have begun investigating methods of generating energy from ambient sources such that the life of the electronics can be prolonged Recent developments in the field have led to the design of a number of mechanisms that can be used to generate electrical energy, from a variety of sources including thermal, solar, strain, inertia, etc Many of these energy sources are available for use with humans, but their use must be carefully considered such that parasitic effects that could disrupt the user's gait or endurance are avoided These issues have arisen from previous attempts to integrate power harvesting mechanisms into a shoe such that the energy released during a heal strike could be harvested This study develops a novel energy harvesting backpack that can generate electrical energy from the differential forces between the wearer and the pack The goal of this system is to make the energy harvesting device transparent to the wearer such that his or her endurance and dexterity is not compromised This will be accomplished by replacing the traditional strap of the backpack with one made of the piezoelectric polymer polyvinylidene fluoride (PVDF) Piezoelectric materials have a structure such that an applied electrical potential results in a mechanical strain Conversely, an applied stress results in the generation of an electrical charge, which makes the material useful for power harvesting applications PVDF is highly flexible and has a high strength, allowing it to effectively act as the load bearing member In order to preserve the performance of the backpack and user, the design of the pack will be held as close to existing systems as possible This paper develops a theoretical model of the piezoelectric strap and uses experimental testing to identify its performance in this application

https://iopscience.iop.org/article/10.1088/0964-1726/16/5/036/pdf

Energy harvesting from a backpack instrumented with piezoelectric shoulder straps

Energy harvesting through a backpack employing a mechanically amplified piezoelectric stack

The use of monolithic piezoceramic materials in sensing and actuation applications has become quite common over the past decade. However, these materials have several properties that limit their application in practical systems. These materials are very brittle due to the ceramic nature of the monolithic material, making them vulnerable to accidental breakage during handling and bonding procedures. In addition, they have very poor ability to conform to curved surfaces and result in large add-on mass associated with using a typically lead-based ceramic. These limitations have motivated the development of alternative methods of applying the piezoceramic material, including piezoceramic fiber composites and piezoelectric 0-3 composites (also known as piezoelectric paint). Piezoelectric paint is desirable because it can be spayed or painted on and can be used with abnormal surfaces. However, the piezoelectric paint developed in prior studies has resulted in low coupling, limiting its application. In order to ...

Enhanced active piezoelectric 0-3 nanocomposites fabricated through electrospun nanowires

Over the past few decades the use of portable and wearable electronics has grown steadily. These devices are becoming increasingly more powerful, however, the gains that have been made in the device performance has resulted in the need for significantly higher power to operate the electronics. This issue has been further complicated due to the stagnate growth of battery technology over the past decade. In order to increase the life of these electronics, researchers have begun investigating methods of generating energy from ambient sources such that the life of the electronics can be prolonged. Recent developments in the field have led to the design of a number of mechanisms that can be used to generate electrical energy, from a variety of sources including thermal, solar, strain, inertia, etc. Many of these energy sources are available for use with humans, but their use must be carefully considered such that parasitic effects that could disrupt the user’s gait or endurance are avoided. This study develops a novel energy harvesting backpack that can generate electrical energy from the differential forces between the wearer and the pack. The goal of this system is to make the energy harvesting device transparent to the wearer such that his or her endurance and dexterity is not compromised. This will be accomplished by replacing the strap buckle with a mechanically amplified piezoelectric stack actuator. Piezoelectric stack actuators have found little use in energy harvesting applications due to their high stiffness which makes straining the material difficult. This issue will be alleviated using a mechanically amplified stack which allows the relatively low forces generated by the pack to be transformed to high forces on the piezoelectric stack. This paper will develop a theoretical model of the piezoelectric buckle and perform experimental testing to validate the model accuracy and energy harvesting performance.© 2007 ASME

Amplified Piezoelectric Stack Actuators for Harvesting Electrical Energy From a Backpack

Over the past few decades the use of portable and wearable electronics has grown steadily. These devices are
becoming increasingly more powerful, however, the gains that have been made in the device performance has resulted in
the need for significantly higher power to operate the electronics. This issue has been further complicated due to the
stagnate growth of battery technology over the past decade. In order to increase the life of these electronics, researchers
have begun investigating methods of generating energy from ambient sources such that the life of the electronics can be
prolonged. Recent developments in the field have led to the design of a number of mechanisms that can be used to
generate electrical energy, from a variety of sources including thermal, solar, strain, inertia, etc. Many of these energy
sources are available for use with humans, but their use must be carefully considered such that parasitic effects that could
disrupt the user's gait or endurance are avoided. These issues have arisen from previous attempts to integrate power
harvesting mechanisms into a shoe such that the energy released during a heal strike could be harvested. This study
develops a novel energy harvesting backpack that can generate electrical energy from the differential forces between the
wearer and the pack. The goal of this system is to make the energy harvesting device transparent to the wearer such that
his or her endurance and dexterity is not compromised. This will be accomplished by replacing the traditional strap of
the backpack with one made of the piezoelectric polymer polyvinylidene fluoride (PVDF). Piezoelectric materials have
a structure such that an applied electrical potential results in a mechanical strain. Conversely, an applied stress results in
the generation of an electrical charge, which makes the material useful for power harvesting applications. PVDF is
highly flexible and has a high strength allowing it to effectively act as the load bearing member. In order to preserve the
performance of the backpack and user, the design of the pack will be held as close to existing systems as possible. This
paper develops a theoretical model of the piezoelectric strap and uses experimental testing to identify its performance in
this application.

Joel Feenstra

Papers

Energy harvesting from a backpack instrumented with piezoelectric shoulder straps

Energy harvesting through a backpack employing a mechanically amplified piezoelectric stack

Enhanced active piezoelectric 0-3 nanocomposites fabricated through electrospun nanowires

Amplified Piezoelectric Stack Actuators for Harvesting Electrical Energy From a Backpack

Harvesting of electrical energy from a backpack using piezoelectric shoulder straps