Aerosol-Jet Printed Antennas for Bluetooth Applications

This thesis presents a comprehensive study on aerosol jet printed (AJP) antennas using silver nanoparticle inks, focusing on their fabrication, microstructural characterization, electrical performance, and wireless functionality. Time-dependent conductivity measurements were performed to investigate the sintering dynamics and electrical stabilization of printed traces, providing insights into the evolution of conductivity with post-printing treatments. Scanning electron microscopy (SEM) was employed to examine the morphology and particle coalescence of antennas subjected to both laser and furnace annealing, revealing distinct differences in microstructure, grain connectivity, and surface porosity between the two annealing methods. Radiofrequency characterization using a vector network analyzer (VNA) allowed evaluation of the S11 parameter, highlighting the impact of printing quality and annealing on reflection loss and impedance matching. Furthermore, Bluetooth range tests were conducted by measuring received signal strength indicator (RSSI) as a function of distance, linking electrical performance to practical wireless communication capability. The results demonstrate that annealing methods significantly influence microstructural evolution, electrical conductivity, and RF performance, emphasizing the critical role of optimized post-processing in achieving reliable, high-performance AJP antennas suitable for wearable and Internet-of-Things (IoT) applications.