Inkjet‐/3D‐/4D‐Printed Nanotechnology‐Enabled Radar, Sensing, and RFID Modules for Internet of Things, “Smart Skin,” and “Zero Power” Medical Applications

The advent of wearable and Internet of Things (IoT)‐connected technologies has enabled and brought to light the potential for a cornucopia of new health‐applied wearable devices. Given a dense implementation of RFID devices for medical and biomonitoring applications owing to the advent of the IoT, a proper way to simultaneously interrogate and gather useful information from an array of sensors is required. An attractive means to achieve this is through the employment of RADAR principles, specifically frequency‐modulated continuous wave. The use of additive manufacturing technologies–such as the commonly encountered inkjet‐printing technology or the popular forms of 3D printing approaches–enables, through their versatility, a surprising wealth of solutions to the limitations of the state‐of‐the‐art health wearables. This chapter presents new strategies enabling the powering of printed wearable systems using both legacy radio‐frequency wireless networks and upcoming 5G millimeter‐wave implementations.