Biopolymer templating is a low temperature, non-toxic method to achieve inorganic-organic hybrid nanostructures, that are interesting for energy conversion through the thermoelectric effect. These devices can generate electrical current from a temperature difference. Today, state of the art thermoelectric generators (TEG) often use toxic and expensive inorganic materials like bismuth (Bi), tellurium (Te), antimony (Sb) or lead (Pb). These materials are toxic and expensive, giving rise to a need for a cleaner and more abundant alternative that still produces good conversion efficiencies.

Beta-lactoglobulin is a bovine whey biopolymer, that is known to form different aggregates under different environmental conditions and also possesses good foamability. [1,2] Therefore, beta-lactoglobulin can be used as a biopolymer template to change the structure of inorganic materials in different ways. Porosity, structure size and structure shape can be tuned, and therefore parameters like the electrical conductivity or the thermal conductivity can be improved.

Beta-lactoglobulin is used to structure Titania (TiO2) using Sol-Gel synthesis with water as the solvent. Slot die coating is used to enable industrial mass-production. A big focus is on the use of non-toxic and abundant materials. The differently structured beta-lactoglobulin-titania thin composite films are studied with SEM, XRD, GISAXS and GIWAXS to correlate the structure with the Seebeck coefficient and electrical conductivity. Also, in situ GISAXS printing is analysed to understand structure formation and evolution.