Converting a Plant to a Battery and Wireless Sensor with Scatter Radio and Ultra-Low Cost

Summarization: Electric Potential (EP) signals are produced in plants through intracellular processes, in response to external stimuli (e.g. watering, mechanical stress, light, acquisition of nutrients). However, wireless transmission of a massive amount of biologic EP signals (from one or multiple plants) is hindered by existing, battery-operated wireless technology and increased, associated monetary cost. In this paper, a self-powered, battery-less EP wireless sensor is presented that harvests near-maximum energy from the plant itself and transmits the EP signal tens-of-meters away with a single switch, based on inherently low-cost and low-power bistatic scatter radio principles. The experimental results confirm the ability of the proposed wireless plant sensor to achieve a fully-autonomous operation by harvesting the energy generated by the plant itself. Also, EP signals experimentally acquired by the proposed wireless sensor from multiple plants, have been processed using Non-negative Matrix Factorization (NMF), demonstrating strong correlation with environmental light irradiation intensity and plant watering. The proposed low-cost, battery-less “plant-as-sensor-and-battery” instrumentation approach is a first but solid step towards large-scale electrophysiology studies of important socioeconomic impact in ecology, plant biology, as well as precision agriculture.Παρουσιάστηκε στο: IEEE Transactions on Instrumentation and Measuremen

A system-level methodology for the design and deployment of reliable low-power wireless sensor networks

Innovative Internet of Things (IoT) applications with strict performance and energy consumption requirements and where the agile collection of data is paramount are rousing. Wireless sensor networks (WSN) represent a promising solution as they can be easily deployed to sense, process, and forward data. The large number of Sensor Nodes (SNs) composing a WSN are expected to be autonomous, with a node's lifetime dictated by the battery's size. As the form factor of the SN is critical in various use cases such as industrial and building automation, minimizing energy consumption while ensuring availability becomes a priority. Moreover, energy harvesting techniques are increasingly considered as a viable solution for building an entirely green SN and prolonging its lifetime. In the process of building a SN and in the absence of a clear and well-rounded methodology, the designer can easily make unfounded decisions about the right hardware components, their configuration and data reliable data communication techniques such as automatic repeat request (ARQ) and forward error correction (FEC). In this thesis, a methodology to better optimize the design, configuration and deployment of reliable ultra-low power WSNs is proposed. Comprehensive and realistic energy and path-loss (PL) models of the sensor node are also established. Through estimations and measurements, it is shown that following the proposed methodology, the designer can thoroughly explore the design space and make most favorable decisions when choosing commercial off-the-shelf (COTS) components, configuring the node, and deploying a reliable and energy-efficient WSN

Wireless Sensor Network Node with Energy Harvesting for Monitoring of Environmental Parameters

U disertaciji je opisan namenski projektovan bežični senzorski čvor namenjen za praćenje parametara životne sredine. Razvijeno rešenje se odlikuje malom cenom i dimenzijama, širokom primenom i minimalnim utocajem na životnu sredinu u poređenju sa primerima iz literature. Koristi se prikupljanje energije sunca iz okoline i superkondenzator za napajanje, što utiče na povećanje životnog veka i smanjivanje troškova održavanja. Izvršena testiranja su potvrdila funkcionalnost predloženog rešenja i mogućnost praćenja različitih parametara korišćenjem komercijalnih i namenski projektovanih senzora. Unapređeno, modularno, rešenje rešava uočena ograničenja i povećava broj parametara životne sredine koji se mogu pratiti.The dissertation describes a specially designed WSN node for application in environmental monitoring. The developed solution is characterized by low price and dimensions, wide application and minimal environmental impact compared to example in literature. Solar energy harvesting and supercapacitor are used as power supply, which increase node lifetime and reduce maintenance costs. The performed tests confirmed the functionality of the proposed solution and the ability to monitor various environmental parameters using commercial and specially designed sensors. The new enhanced solution, with modular design, solves the observed limitations and increases the number of environment parameters that can be monitored