The goal of bioelectronics is to interface electrical devices with living tissues, cells and biological fluids to achieve a range of functions: from monitoring biological activity to controlling neuron signals and administering drugs. The materials developed to build these interfaces are typically organic materials containing polymeric conjugated chains combined with ionic components in water. At the moment there is no clear structure-function theory for these materials and no microscopic understanding of how they operate or why some of them perform better. The overall goal of this proposal is (i) to lay the foundations for atomistic modelling of organic bioelectronics materials, (ii) to derive structure-property relations from the study a range of experimentally relevant systems and (iii) to address some of the most pressing scientific questions arising in the field. These objectives cannot be achieved with any of the existing methodologies. The physics of ion dynamics coupled with the dynamics of very fast electrons is new and outside the capabilities of current classical or quantum simulation tools. The materials are chemically too complex and diverse to simulate a sufficient number of them with the common methods of soft matter simulations. This proposal addresses both the physical aspects (developing a new method to describe ion-electron coupled dynamics) and the computational aspects (devising a scheme for accelerated simulations of polymeric materials), providing this research field with a robust and predictive theory.