The main results from the work performed during the reporting period along the different WPs are:
WP1 has focused on the synthesis and characterization of conductive protein and peptide sequences. These include the generation of a collection of efficient ionic and electronic conductive systems based on engineered proteins and peptides. Moreover, we have generated a set of self-assembled 1D and 2D biomolecular materials. For the implementation of these systems in devices, successful upscale protein production has been achieved.
WP2 has focused on the characterization of the local structural, electrical, and mechanical properties of ePs assemblies, resulting in demonstrated enhanced ionic conductivity encoded by engineered charged amino acids in proteins (CTPR-E series) and electronic conductivity encoded by aromatic amino acids in peptide assemblies (TZ-peptides). Additionally, ion conductivity in protein films was improved by two orders of magnitude through external doping with salt, resulting in performances not previously achieved by biomaterials. Moreover, computer simulations have been used to understand the intramolecular ionic and electronic transport mechanisms. The best-performing engineered ePs have been identified for both ionic and electronic conduction and selected for further processability studies and device implementation.
WP3 has focused on the formulation and manufacturing of electrolyte films and inks based on protein materials and the preparation of flexible electrodes using both standard and novel binders, and development of structuration methods. Various strategies for producing ionic conductive electrolyte films using the CTPR-E series were explored. Formulations combining proteins with various resins were generated, and their processability, compatibility, and material properties were investigated. Conductive proteins (CTPR-E series) and peptides (TZ-peptides) were formulated as doping agents for EDOt polymerization, resulting in hybrid PEDOT:ePs biomaterials with conductive properties comparable to the gold standard PEDOT:PSS. Ink formulations for screen and inkjet printing were successfully developed using hybrid PEDOT:ePs materials. Additionally, novel water-based flexible electrodes were developed using various aqueous based binders.
WP4 has focused on exploring the implementation of conductive e-Ps in printable circuits and supercapacitors as well as on demonstrating of device fabrication and performance characterization. Several printing approaches were tested using PEDOT:CTPR formulations, and key parameters for printing and curing were optimized. Despite challenges related to ink rheology and printability, dispenser printing showed promising results. Regarding device integration, efficient incorporation of ionically conductive proteins into supercapacitor devices was achieved, resulting in excellent performance in terms of capacitance, coulombic efficiency, and operational stability, comparable to standard systems. Moreover, the technology was successfully translated into textile supercapacitors using spray-coated carbon electrodes on fabrics, which showed stable capacity and good mechanical flexibility. Finally, all-protein-based organic electrochemical transistor (OECT) prototypes combining TZ-PEDOT as the channel and CTPR-4E as the electrolyte were fabricated and characterized, demonstrating the feasibility of fully biomolecular electronic devices.
WP5 has established the website and LinkedIn account and has establishment of the intellectual property rights and exploitation strategy. eProt consortium has disseminated research outputs regularly, with several published manuscripts and participation in Scientific Conferences and Workshops.
