Fig. 1. Bridging electronic and biomolecular communication through redox.

a Electronic communication (left) mainly relies on free-flowing electron transfer or electromagnetic waves for communication. Molecular communication (right), conversely, employs signaling chemical molecules for information transfer. The redox modality can connect the two disparate communication modalities with redox-active molecules that can interact with both electronics and biology. Electro-biofabrication enables the creation of transmission interfaces and electrogenetics enables specific activation of engineered genetic circuits. b The redox signaling modality enables connection of biology to electronics in both directions. Here, an encoded electronic input is first transduced to chemical signals: (i) an oxidized redox mediator (ferrocence, Fc) that facilitates hydrogel assembly and (ii) reduced oxygen (O₂ is reduced to H₂O₂) that is interpretable by several biological subsystems at the protein (top), cellular (middle), and multicellular (bottom) levels. Optical signals (e.g., fluorescence) generated by cells, as well as electrochemical currents (from peroxide generation), are recorded, computed upon, and fed back into process control algorithms for control, establishing an electro-bio-electro communication loop.