Inkjet-printed memory cards have been developed previously by re-searchers at Mid Sweden University but, these did possess some limita-tions, as each resistive memory cell required one physical contact and the resistances were designed to be electrically programmed.This work overcomes the above limitations by developing chemically programmed printed memory cards and a PC connected memory card reader. Printed memory cards are inexpensive and are developed by inkjet printing the nano-silver ink onto the photo paper substrate. A matrix readout method is used to increase the num-ber of memory cells and, by using a chemical solvent, the resistances were programmed to the desired resistance values and, for which, each resistance value represents data on the cards, called, write once read many (WORM) memories. The memory card reader was developed to access the data (resistance value) of the memory card and also to trans-mit the data to a LabVIEW graphical user interface for displaying the resistance values. By using multiple resistance steps, in which each step represents a different state, it is possible to create a number of possible selectable combinations which can be programmed at a later stage for developing applications.

A wearable body temperature sensor would allow for early detection of fever or infection, as well as frequent and accurate hassle-free recording. This thesis explores the design of a body-temperature-sensing device inkjet-printed on a flexible substrate. All structures were first modeled by first-principles, theoretical calculations, and then simulated in HFSS. A variety of planar square inductor geometries were studied before selecting an optimal design. The designs were fabricated using multiple techniques and compared to the simulation results. It was determined that inductance must be carefully measured and documented to ensure good functionality. The same is true for parallel-plate and interdigitated capacitors. While inductance remains relatively constant with temperature, the capacitance of the device with a temperature-sensitive dielectric layer will result in a shift in the resonant frequency as environmental or ambient temperature changes. This resonant frequency can be wirelessly detected, with no battery required for the sensing device, from which the temperature can be deduced. From this work, the optimized version of the design comprises of conductive silver in with a temperature-sensitive graphene oxide layer, intended for inkjet-printing on flexible polyimide substrates. Graphene oxide demonstrates a high dielectric permittivity with good sensing capabilities and high accuracy. This work pushes the state-of-the-art in applying these novel materials and techniques to enable flexible body temperature sensors for future biomedical applications.

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