Research

Research

Research Vision

The swift progression of Internet of Things (IoT) techniques has driven a surge applications in precision agriculture, smart cities, and environment monitoring. These applications, which encompass vast numbers of wireless devices, pose a significant challenge to sustainability, as powering large quantities of devices over extensive areas via power grids or batteries is not scalable. Energy harvesting emerges as a promising solution. As a viable alternative, energy harvesting technology presents a sustainable and scalable solution, utilizing renewable energy sources in the environment such as solar, RF energy, and vibration energy to power IoT devices. Although, this Sustainable IoT (SIoT) approach allows for near-perpetual operation without battery replacements, it necessitates vigilant oversight to ensure efficiency and security. In light of these challenges, my research aims to tackle issues of sustainability, efficiency, and security within the realm of SIoT networks. 

RF-Powered IoT in Extreme Environments: Efficient Charging and Low-Power Communication (Soil Enviornment)

Motivation: For soybeans, cottons and corns, which are the most commonly grown crops in Southern states and Midwest of United States, the majority of water and nutrient uptake occurs in the top 30-60 cm of the soil profile. Insufficient nutrition and poor drained soil will limit the root development of plants, degrading overall plant health and productivity. Therefore, monitoring the soil conditions at 30 cm layer in the long-term and scalable manner is critical in digital agriculture. The goal of this project is to develop battery-free and solar panel-free Subterranean Internet of Things (SIoT) systems to monitor soil parameters. A mobile platform (e.g., UGV, UAV) will be used to charge SIoTs and collect sensing data.

1) Challenges in deep soil charging: Due to the high signal attenuation in soil, the transmit power must be sufficiently high for RF energy to reach SIoTs buried 30 cm deep in the soil. However, the energy supply and payload of the mobile platform are limited. Therefore, an efficient energy emission strategy is required for SIoT charging.

2) Challenges in low-power communication: Active communication modules, which have a substantial power consumption are not practical for use in SIoT. Current RFID systems (i.e., RF backscatter communications) are not suitable for operations at a depth of 30 cm in soil, mainly due to the high signal attenuation within the soil and the considerable depth involved.

Related Publications:  IEEE Trans. on Industrial Informatics'23

Nov. 2022 Initial lab testing of RF backscattered communications