Luis Pereira

Abstract:

The growing demand of new and sustainable consumer printed electronics led to the increased interest in devices integrating natural materials. Here we present the wok resulting from recent research concerning the application of cellulose based materials in flexible electronic devices. First topic is related to with the development of electrolytic membranes to be used as dielectric in transistors exploring the high capacitance that can be obtained by the formations of electric-double layers. Second topic to be addressed are printable inks based on commercial carbon fibers and zinc oxide nano-particles mixed with some cellulose derivatives that were optimized to create printed active layers at temperatures lower than 150 °C. This allowed the development of fully screen-printed sensors and transistors with mobility above 10 cm²V^-1s^-1 and on/off current ratio higher than to 10⁵ on substrates like paper and cork. Finally, we will show how cellulose nano-crystals can self-assemble in a chiral nematic structures that mimic those existing in nature. These can be then used as dielectric in field effect transistors making possible the detection of circular polarized light in such devices.