From biopigments to bioelectronics: modelling semiconducting eumelanin-based interfaces
The overall aim of this proposal is to build a comprehensive model of ionic and electronic transport in organic bioelectronics considering a prototypical material, eumelanin, as a proof of concept. Bioelectronic devices are used in nanomedicine for implantable, wearable and sensing applications. Eumelanin is a natural biocompatible semiconductor with great potential in bioelectronics due to its joint electronic and ionic conductivity. However, a full picture of its interactions with water and electrolytes and how these influence its semiconducting properties is still missing, thus holding back a systematic improvement of eumelanin-based devices. This project will provide the first unified picture of eumelanin’s mixed conduction by simulating electronic and ionic charge transport at device-relevant scales and combining them in a numerical model. This will be achieved through four innovative steps towards eumelanin characterisation:  i) reactive molecular dynamics (MD) simulations will capture the details of water-eumelanin interactions;  ii) a classical MD approach will describe ionic conduction in hydrated eumelanin;  iii) electronic structure methods will relate eumelanin’s morphology to its electronic conductivity.  iv) The previous insight will be combined in a model describing mixed conduction in eumelanin-based devices, allowing the formulation of general design rules for the development of new bioelectronic materials. Planned collaborations with leading groups in eumelanin bioelectronics will provide experimental data to build and validate the model, resulting in high-impact publications and contributing to European competitiveness in bioelectronics. The complementary nature of the researcher and host’s research profiles is instrumental in fulfilling the complex, interdisciplinary aims of the project. The Fellowship will allow the researcher to expand her knowledge beyond her existing skills, enabling her transition  towards an independent academic career.