Paper Substrate for Printed Functionality

Abstract

Requirements for paper to be used as substrate for printed functionality were investigated. A recyclable, multilayer-coated paper substrate that combines adequate barrier and printability properties for printed electronics and sensor applications was developed. In this multilayer structure, a thin top-coating consisting of mineral pigments is coated on top of a dispersion-coated barrier layer. The top-coating provides well-controlled sorption properties through controlled thickness and porosity, thus enabling optimizing the printability of functional materials. The optimum barrier layer structure was investigated by studying the influence of latex type and amount in blends with different size and shape factor kaolin pigments. Highly aligned high shape factor kaolin improved barrier properties in general, but was found especially useful against organic solvents, which may degrade the latex. Dimensional stability and its influence on substrate surface properties as well as on functionality of conductive tracks were studied by exposure to high/low humidity cycles. The barrier layer of the multilayer coated paper reduced the dimensional changes and surface roughness increase caused by humidity and helped maintain the conductivity of printed tracks. As proof of concept functional devices, hygroscopic insulator field effect transistors were printed on the multi- layer curtain coated paper using a custom-built roll-to-roll hybrid printer.