This paper presents a RH smart humidity sensor fabricated using poly vinyl alcohol (PVA) as sensing film deposited on polyimide substrate. This sensor detects change in capacitance due to presence of humidity in gas insulated switchgear (GIS) application. The initial tests are conducted using moist nitrogen gas with different percentage relative (% RH). The performance of designed PVA sensor was experimentally validated and it is noticed that the sensor possesses good sensitivity with linear characteristics over the range of 0- 20% suitable for industrial practices. Further, other parameters of the sensors such as reproducibility test, transient response analysis, linearity analysis, impedance response, and dissipation factor were also conducted to test the stability and effectiveness of the designed sensor. COMSOL Multiphysics is also used to validate the design aspects of the sensor with the fabricated one. The uniqueness of the fabricated sensor is that it is demonstrated good sensitivity profile along with the excellent linear response for the measurement of low RH values. The cost effectiveness of the sensor ensures due to simple fabrication process, use of inexpensive materials and 100% yield ratio.

Public lighting is a ubiquitous utility in cities to ensure the safety of people. In addition to playing a significant role in amending the comfort and safety of cities, street lighting causes substantial financial burden on governments to maintain its operation. Smart Light Emitting Diode (LED) street light system has become a prominent alternative to conventional street lighting systems with the involvement of Internet of Things (IoT). In this manuscript, a supercapacitor based smart street management system with energy autonomous capability has been proposed. It works in real-time and as an energy-saving alternative to prevent unnecessary electricity consumption of the street light. The average current consumption and power consumption of the system are 619.14 $\mu$ A and 2.022 mW, respectively. Three charging schemes have been investigated to find the optimized topology to harvest energy. The proposed device harvests energy from ambient sunlight and artificial light using a solar cell of 64 mm × 37 mm × 0.22 mm with maximum output power of 66 mW. LoRaWAN has been incorporated for communication, with a communication range of 761 m in real-world testbed. The operation characteristics and performance evaluation has been done based on implementing the system in field to ensure seamless operation.

Street lighting is one of the prominent applications that demand a massive amount of power and substantially contributes to the energy budget of a country. Light Emitting Diode (LED) and the advancement of Internet of Things (IoT) have significantly improved conventional street light technology. Nevertheless, the rapid growth of IoT devices has presented a formidable challenge in powering the vast array of IoT devices. In this manuscript, a sustainable, battery-free, low-power street light management system has been proposed which is powered from hybrid solar and solar thermal energy harvesting scheme integrated with an efficient power management unit. As a specific case study, the prototype has been implemented with an existing LED street light in India. The characteristics and performance of the prototype have been evaluated to ensure its seamless operation under real-world scenarios. The average power consumption of the system is measured as 2.088 mW when operating in real-time with 50% duty cycle, exhibiting high Quality of Service (QoS). It features long-range communication up to 761 m through implementing LoRaWAN technology. Dimension of the prototype has been restricted to 10.5 cm x 6.5 cm x 2.3 cm to make it suitable for retrofitting with existing LED based street lights

Solid waste management has emerged as a significant challenge in smart cities, resulting in severe health and environmental concerns. Municipal tash bins are strategically placed throughout a city; nevertheless, in the absence of real-time monitoring, these bins are often observed to be overflow. It results in environmental pollution, and adverse effects on public sanitation. Thus, there is substantial necessity of real-time solid wate management using which helps the concerned authority in real-time monitoring and accordingly schedule garbage cleaning. This work proposes a sustainable, LoRaWAN-enabled battery-free smart garbage bin framework. The proposed system can harness energy from sunlight using a thin-film Photovoltaic (PV) harvester integrated with an ultra-low power management system. Subsequently, it powers the sensor node to measure the garbage level and trasmit it to a cloud-hosted application sever. Long Range Wide Area Network (LoRaWAN) technology has been incorprated for wireless communication which operates at 867 MHz and covers a communication range up to 361 meter within dense populated area. It has been observed experimentally, that the system harvests energy at an average rate of 10.44 mW under clear sky condition. Subsequently, the power consumption of the system has been optimized using duty cycle technique resulting in average consumption of 131 μW. On the other hand, a hybrid multi-objective framework has been proposed integrating Tiny Machine Learning (TinyML) and Tiny Genetic Algorithm (TinyGA) techniques. The framework predicts the garbage fullness in a garbage bin exhibiting an accuracy of 96.22 % and subsequently provides an optimized route for the garbage cleaning vehicle for maintenance. It ensures minimum fuel consumption, travel distance, travel time, emissions, and cost in garbage cleaning vehicles. The system has been extensively deployed on a real-world test bed to validate its sustainable operation. Thus, the proposed system can be considered as an ultra-low power battery-free alternative to state-of-the-art smart solid waste management systems that align with Sustainable Development Goal (SDG) 7 of the United Nations.

Consumer lighting plays a significant role in the development of smart cities and smart villages. With the advancement of (IoT) technology, smart lighting solutions have become more prevalent in residential areas as well. These solutions provide consumers with increased energy efficiency, added convenience, and improved security. On the other hand, the growing number of IoT devices has become a global concern due to the carbon footprint and carbon emissions associated with these devices. The overuse of batteries increases maintenance and cost to IoT devices and simultaneously possesses adverse environmental effects, ultimately exacerbating the pace of climate change. Therefore, in tandom with the principles of Industry 4.0, it has become crucial for manufacturing and research industries to prioritize sustainable measures adhering to smart energy as a prevention to the negative impacts. Consequently, it has undoubtedly garnered global interest from scientists, researchers, and industrialists to integrate state-of-the-art technologies in order to solve the current issues in consumer light management systems making it a complete sustainable, and smart solution for consumer lighting application. This manuscript provides a thorough investigation of various methods as well as techniques to design a state-of-the-art IoT-enabled consumer light management system. It critically reviews the existing works done in consumer light management systems, emphasizing the significant limitations and the need for sustainability. The top-down approach of developing sustainable computing frameworks for IoT-enabled consumer light management has been reviewed based on the multidisciplinary technologies involved and state-of-the-art works in the respective domains. Lastly, this article concludes by highlighting possible avenues for future research.