Zero Energy IoT Devices in Smart Cities Using RF Energy Harvesting

Abstract

The invention of batteries made it possible to store electricity for many purposes. One of the purposes is to keep the operations of WSN running without any interruptions. The main drawback of sensor nodes is their limited energy sources. The researcher introduces the energy harvesting (EH) concept for IoT-based WSNs to overcome energy limitations and charge the IoT devices. Many energy harvesting techniques have been introduced, such as solar, thermal, and flow-based ones, but radio frequency (RF)-based EH techniques received great attention from researchers due to their easy availability (from TV, radio, and wireless frequencies). In this paper, we have conducted a real-world experiment on Powercast energy harvesting devices and examined the behavior of sensed data in different scenarios, such as indoor, distance (feet/meters), and directional antennas. In our experiments, we have observed that when a device is removed from the charger, the energy scavenging process degrades and reaches a dead state. To stop a device from entering a dead state, we introduce a mobile charger technique to charge the device and find the optimal place for chargers and sensor devices. During mobile charging, we have also observed that when the directional antennas change their angle, the energy scavenging process degrades. To tackle these problems, we introduced two algorithms for directional and omni-directional antennas that efficiently solve the problem. Furthermore, we have obtained results for these scenarios and show that this technique has a promising output.

Reconfigurable Antennas for RF Energy Harvesting Application: Current Trends, Challenges, and Solutions from Design Perspective

“…In order to balance the trade-offs [7], microwave antennas are the top-most priority. They are classified as dipole antennas [18][19][20][21], monopole antennas [22][23][24][25], loop antennas [26][27][28][29], slot antennas [30][31][32][33], microstrip antennas [34][35][36][37], Vivaldi antennas [38][39][40][41], and DRAs [42][43][44][45]. Further, the classification is divided into helical antennas [46][47][48][49], Yagi-Uda antennas [50][51][52][53], and log-periodic antennas [54][55][56][57].…”

Aerosol Doping System for Microscale Seamless p–n Patterning of Carbon Nanotube Films

“…The Internet of Things (IoT) comprises physical devices, vehicles, robots, and living things, including humans, that are interconnected through networks. Data exchange through embedded terminals realizes innovative technologies, such as improved work efficiency through cooperation, automated driving systems, and real-time biological monitoring, for practical use. − To overcome power supply problems for embedded terminals, such as infrastructure sensors and smart watches, energy-harvesting technologies that generate power from ambient is essential for realizing IoT. − Energy-harvesting technologies that convert various ambient energies, such as light, heat, vibration, and static electricity, into power have been extensively explored. − Among these, thermoelectric generators (TEGs), which convert heat into electricity, have stable power generation regardless of weather conditions or mechanical drive mechanisms. Various types of TEGs have been developed, such as metal alloys with high thermoelectric conversion capabilities and flexible soft materials suitable for clothing applications. − Recently, single-walled carbon nanotubes (CNTs) have gained increasing attention as a potential thermoelectric material. − Theoretical and experimental studies have proven that controlling specific parameters, such as chirality, length, and carrier concentration, can lead to high thermoelectric conversion ability, as demonstrated by the power factor PF and figure of merit ZT .…”

A Low-Voltage Self-Starting Boost Converter Using MPPT with Pulse Multiplication for Energy Harvesting

“…With the rapid development of Internet-of-Things (IoT) technology in recent years [1,2], the proliferation of wearable devices and wireless sensors [3] for preventive medicine and continuous vital sign monitoring has surged [4][5][6], marking a trend towards increased integration. Energy harvesting technology enables the conversion of various forms of energy, such as thermal [7], solar [8], and radio frequency [9], into electrical power, thereby providing a continuous and stable energy supply for these devices.…”