Low-Cost Inkjet-Printed Wireless Sensor Nodes for Environmental and Health Monitoring Applications

摘要

Increase in population and limited resources have created a growing demand for audfuturistic living environment where technology enables the efficient utilization andudmanagement of resources in order to increase quality of life. One characteristic of suchuda society, which is often referred to as a ‘Smart City’, is that the people are welludinformed about their physiological being as well as the environment around them,udwhich makes them better equipped to handle crisis situations. There is a need,udtherefore, to develop wireless sensors which can provide early warnings and feedbackudduring calamities such as floods, fires, and industrial leaks, and provide remote healthudcare facilities.udFor these situations, low-cost sensor nodes with small form factors are required. Forudthis purpose, the use of a low-cost, mass manufacturing technique such as inkjetudprinting can be beneficial due to its digitally controlled additive nature of depositingudmaterial on a variety of substrates. Inkjet printing can permit economical use of materialudon cheap flexible substrates that allows for the development of miniaturized freeformudelectronics.udThis thesis describes how low-cost, inkjet-printed, wireless sensors have beenuddeveloped for real-time monitoring applications. A 3D buoyant mobile wireless sensorudnode has been demonstrated that can provide early warnings as well as real-time dataudfor flood monitoring. This disposable paper-based module can communicate whileudfloating in water up to a distance of 50 m, regardless of its orientation in the water.udMoreover, fully inkjet-printed sensors have been developed to monitor temperature,udhumidity and gas levels for wireless environmental monitoring. The sensors areudintegrated and packaged using 3D inkjet printing technology. Finally, in order touddemonstrate the benefits of such wireless sensor systems for health care applications, audlow-cost, wearable, wireless sensing system has been developed for chronic woundudmonitoring. The system called ‘Smart Bandage’ can provide early warnings and long termuddata for medical diagnoses. These demonstrations show that inkjet printing canudenable the development of low-cost wireless sensors that can be dispersed in theudenvironment or worn on the human body to enable an internet of things (IoT), whichudcan facilitate better and safer living.