Piezoelectric Energy Harvester for IoT Sensor Devices

Limited battery power is a major challenge for wireless sensor network (WSN) in internet of things (IoT) applications, especially in hard-to-reach places that require periodic battery replacement. The energy harvesting application is intended as an alternative to maintain network lifetime by utilizing environmental energy. The proposed method utilized piezoelectricity to convert vibration or pressure energy into electrical energy through a modular piezoelectric energy harvesting design used to supply energy to sensor nodes in WSN. The module design consisted of several piezoelectric elements, of which each had a different character in generating energy. A bridge diode was connected to each element to reduce the feedback effect of other elements when pressure was exerted. The energy produced by the piezoelectric is an impulse so that the capacitor was used to quickly store the energy. The proposed module produced 7.436 μJ for each step and 297.4 μJ of total energy with pressure of a 45 kg load 40 times with specific experiments installed under each step. The energy could supply WSN nodes in IoT application with a simple energy harvesting system. This paper presents a procedure for measuring the energy harvested from a commonly available piezoelectric buzzer. The specific configurations of the piezoelectric and the experiment setups will be explained. Therefore, the output energy characteristics will be understood. In the end, the potentially harvested energy can be estimated. Therefore, the configuration of IoT WSN could be planned.

NUMERICAL MODELLING OF OSCILLATING FLOW FOR ENERGY HARVESTING

The energy efficiency of systems, equipment, and sensors is nowadays intensively studied. The new generation of microelectronic sensors is very sophisticated and the energy consumption is in the microwatts range. The energy to power the microelectronic devices can be harvested from oscillating flow in small size channels and so replaceable batteries could be eliminated. Piezoelectric elements can convert energy from oscillation to electrical energy. This paper focuses on the simulation of periodic flow in the fluidic oscillator. CFD simulations were performed for several values of the flow rate. Experimental measurement was carried out under the same conditions as the CFD experiment. The main monitored and evaluated parameters were volume flow rate and pressure loss. Fluid oscillations were analysed based on CFD simulations and the theoretical maximum energy available for the deformation of piezoelectric elements and transformable into electrical energy was evaluated.

Modelling vibrations of axial piezoelectric generator with active base

Modelling of an axial-type piezoelectric generator (PEG) is considered. PEG is an integral part of the system for converting mechanical vibration energy from the environment into electrical energy. The energy generator has an axial type of the configuration of elements, aimed on using bending and compressive loads simultaneously on piezoelectric elements. The base of the generator is made as an active pinching. A feature of PEG is that the generator has two types of piezoelectric elements: (1) elements located on the substrate in the form of a bimorph and (2) piezoelectric elements of a cylindrical shape, fixing the generator base, located on the same axis. PEG has a symmetrical structure about the center of proof mass. The results of modal and harmonic analysis of vibrations are given for vibration excitation of the PEG base in a certain frequency range. The analysis of the output characteristics is given.

Simulation modeling of composite piezotransformer measuring transducer with differential output

The article presents the results of using simulation modeling to study the output characteristics of composite piezotransformer measuring transducers with a differential output. The processes were simulated using the Micro-Cap software. The article presents options for controlling the parameters of the equivalent electrical circuit of the converter. The article presents the results of simulation of composite piezotransformer measuring transducers with two degrees of freedom. Structurally, they can include piezoelectric elements, additional vibrators and communication elements between them. This allows you to expand their functionality, scope of practical application. The advantages are applicable to work in difficult and even extreme conditions. On the basis of such measuring transducers, prototypes of highly sensitive sensors were developed for measuring pressures, forces, temperature and other physical quantities, for monitoring the physical and mechanical characteristics of solids, liquid and gaseous media.

Design of Piezoelectric Tile for Energy Harvesting: Experimental Approach

The generation of electricity by renewable energies is an important need of today's society. Piezoelectric energy harvesting is one of these useful technologies which can generate electricity by applying external force on piezoelectric material. This study illustrates more power generation from piezoelectric tile by changing the situation of piezo discs and connect to proportional electrical circuit. Two different designs of piezoelectric tile are presented by performing experimental analyses. The experimental results showed that placing piezoelectric elements in a bending position leads to higher power generation in comparison with traditional flat positioning, which was approximately 78 times far superior. It is also revealed that by design of an electrical circuit, the tile can be advantageous for lighting in crowded sidewalks with required lighting time. The results of this paper can be beneficial in the design and fabrication of these tiles for different applications.