Brewer's spent grain (BSG) represents the main by-product of the brewing industry, accounting for ~ 85 % of the total by-products. The annual global production of BSG is massive, that is ~ 40 million tons. In the European Union, the production is ~ 3,4 million tons/year [1]. Currently, BSG is mainly sold to farmers (~ 30 % in EU) as animal feed, with a low market value of ~ 35 Euro/ton or landfilled. Finding alternatives, higher value uses for BSG is therefore particularly attractive from the point of view of brewery economics [1]. Besides, disposable electronics applications such as in smart food and beverage packaging require environmentally safe devices with low cost and large volume processability. Therefore, switching from nonrenewable manufacturing to sustainable processes is a major challenge for next generation electronics, and organic materials offer a unique opportunity to drive the electronic industry in an environmentally safe direction [2]....
