Design, fabrication, and characterization of printable and flexible sensors and functional devices

This thesis work focuses on the design, fabrication and characterization of functionalized metal nanomaterials and exploration of applications in printable electronics, flexible sensors and thermoelectric energy conversion devices. The ability to design and fabricate functionalized devices requires fundamental understanding of the correlation between the structure of nanomaterials, including size, shape, composition, and surface properties, and their unique properties. One area of our studies involves the correlation between laser sintering parameters and nanoalloy ink printed device performance in both experimental and theatrical aspects. Another area mainly focuses on the design and fabrication of nanoparticle-structured thin film sensors on flexible substrates for both chemical sensors and strain sensors, which show great potential in lung cancer detection and wearable devices. The last area investigates the fabrication of a nanocomposite thin-film thermoelectric device which harvests nanocatalytic heat localized in nanoalloy catalyst in catalytic methanol combustion for thermoelectric conversion on CuS-based nanomaterials. New strategies have been developed to make copper-based flexible electronic devices exhibiting good conductivity and enhanced stability in ambient environment by effectively coupling nanoink-printing and pulsed laser sintering. New insights into the design and fabrication of flexible strain sensors with high gauge factor and anisotropic property have been gained by tuning nanostructure parameters in terms of particle size, interparticle spacing and interparticle structures. The viability of nanostructured sensor array for breath recognition of lung cancer patients under ambient sensing conditions has been successfully demonstrated, showing potential application in cancer screening in the future. A promising pathway for harvesting nanocatalytic heat localized in a nanoalloy catalyst layer as a heat source in a nanocomposite thin film thermoelectric device for thermoelectric energy conversion has been developed.