An Energy Harvester for Low-Frequency Electrical Signals

Generating electricity from low-frequency mechanical agitations produced by ocean waves, plants, or human motion is emerging as a key, environmentally friendly technology in combating harmful emissions caused by burning fossil fuels. The electric pulses generated by the appropriate transducers, such as triboelectric or piezoelectric generators,...

Flexible Lead-Free Piezoelectric Composite Materials for Energy Harvesting Applications

A novel method based on the Virtual Particle Mori–Tanaka (VPMT) is developed to predict the effective electro-elastic properties, d33 and g33, of structured piezoelectric particulate composites with improved accuracy by means of a single parameter related to the spatial distribution of imperfectly aligned rod-like PZT particles. The VPMT method...

Flexible Lead-Free Piezoelectric Composite Materials for Energy Harvesting Applications

Vibrational piezoelectric energy harvesters are being investigated to replace batteries in embedded sensor systems. The energy density that can be harvested depends on the figure of merit, d 33 g 33 , where d 33 and g 33 are the piezoelectric charge and voltage coefficient. Commonly used piezoelectric materials are based on inorganic ceramics,...

Harvesting roadway solar energy-performance of the installed infrastructure integrated pv bike path

Solar road technology provides an opportunity to harvest the vast, albeit dispersed, photovoltaic (PV) energy, while maximizing the land utilization. Deriving experience from the pioneering 70-m solar bike path installed in the Netherlands, this paper highlights the operational challenges and performance parameters using the first-year measured...

Enhancing energy harvesting potential of (K,Na,Li)NbO3-epoxy composites via Li substitution

In this study, the influence of Li substitution on the piezoelectric performance of lead-free K0.5Na0.5NbO3 (KNN)-epoxy composites is explored. KNN piezoceramic particles modified with 0-12 mol% of Li are prepared via a double calcination technique, resulting in a perovskite particulate which transitions from an orthorhombic to tetragonal...

Exploring the piezoelectric performance of PZT particulate-epoxy composites loaded in shear

The active and passive piezoelectric response of lead zirconium titanate (PZT)-epoxy particulate composites loaded in shear is studied using analytical models, a finite element model and by experiments. The response is compared to that of the same composites when loaded in simple tension. Analogously to bulk PZT, particulate PZT-polymer...

Sensing and Energy Harvesting Novel Polymer Composites

This chapter describes the development and properties of novel functional composite materials consisting of aligned piezo-ceramic particles or fibers in a polymeric matrix, which can be fully integrated in thermoset or thermoplastic products. The materials have a low potential for applications requiring actuation but have attractive sensorial...

Robust piezoelectric composites for energy harvesting in high-strain environments

High-strain environments, such as are found in automobile tires, provide deformation energy that can be harvested using piezoelectric materials, for instance, for powering electronics such as wireless sensors. Despite numerous efforts, none of the present devices easily satisfy the stringent operating and lifetime requirements for use inside a...

Micromachined polycrystalline si thermopiles in a T-shirt

The technology for in-plane poly-Si thermopiles has been developed. The bulkmicromachined thermopiles are located between two Si bars and connected thermally with those bars through thin-film thermal shunts. The patterned strips of thermocouple material together with thermal shunts form bridges between Si bars. Two versions of a thermoelectric...

Harvesting energy from airflow with a michromachined piezoelectric harvester inside a Helmholtz resonator

In this paper we report an airflow energy harvester that combines a piezoelectric energy harvester with a Helmholtz resonator. The resonator converts airflow energy to air oscillations which in turn are converted into electrical energy by a piezoelectric harvester. Two Helmholtz resonators with adjustable resonance frequencies have been designed...

Design, modeling, fabrication and characterization of an electret-based MEMS electrostatic energy harvester

This paper reports on the design, modelling, fabrication and characterization of an electret-based MEMS electrostatic energy harvester with an elegant and robust process flow. The fabrication is based on a SOI wafer with self-aligned electrodes of the variable capacitor. The output current of the device shows distinct steps that are caused by...

Human++: Wireless autonomous sensor technology for body area networks

Recent advances in ultra-low-power circuits and energy harvesters are making self-powered body wireless autonomous transducer solutions (WATS) a reality. Power optimization at the system and application level is crucial in achieving ultra-low-power consumption for the entire system. This paper deals with innovative WATS modeling techniques, and...

A batch process micromachined thermoelectric energy harvester: Fabrication and characterization

Micromachined thermopiles are considered as a cost-effective solution for energy harvesters working at a small temperature difference and weak heat flows typical for, e.g., the human body. They can be used for powering autonomous wireless sensor nodes in a body area network. In this paper, a micromachined thermoelectric energy harvester with 6...

Energy autonomous sensor systems: Towards a ubiquitous sensor technology

Energy efficiency of electronic systems has emerged as one of the most important trends in integrated circuits research in recent years. The results of this continued effort are visible in all kinds of electronic functions: DSPs (reaching the 10 μW/MMAC according Gene's law), data converters (the FOM of recent ADCs is approaching 15 fJ...

Vacuum-packaged piezoelectric vibration energy harvesters: Damping contributions and autonomy for a wireless sensor system

This paper describes the characterization of thin-film MEMS vibration energy harvesters based on aluminum nitride as piezoelectric material. A record output power of 85 μW is measured. The parasitic-damping and the energy-harvesting performances of unpackaged and packaged devices are investigated. Vacuum and atmospheric pressure levels are...

Role of gut microbiota in the control of energy and carbohydrate metabolism

Purpose of review: To describe the recent developments and insights gained in the role played by the colonic microbiota in energy and carbohydrate metabolism related to obesity in humans. Recent findings: Previous findings that the ratio of Firmicutes and Bacteriodetes is important in energy harvesting and obesity have not been confirmed in...