The most relevant process of light-energy conversion in nature is photosynthesis, which takes place within the thylakoid membrane of cyanobacteria and chloroplasts. The thylakoid membrane is a lipid bilayer that assembles multiple protein supercomplexes in a transmembrane fashion to absorb light and transfer electrons across the membrane to generate high-energy products such as NADPH (nicotinamide adenine dinucleotide phosphate hydrogen) and carbohydrates as well as oxygen as a side product. The benefit of transmembrane electron transfer is that the oxidation site is physically separated from the reduction site and that such compartmentalization can fine-tune local reaction conditions to prevent detrimental recombination. Additionally, the transmembrane charge transfer generates a proton gradient which fuels the ATP synthase (ATP = adenosine triphosphate, see Figure ). Current artificial photosynthetic systems mostly investigate either an individual catalytic light-driven reduction (e.g., H2 evolution, 6 CO2 reduction ) or an individual oxidation reaction (e.g., water oxidation), both of which are still relying on the use of sacrificial reagents. A useful oxidation and reduction reaction combination is challenging due to their typically different reaction conditions and reported examples also rely on sacrificial reagents. For instance, reduction reactions such as H2 evolution perform best under acidic conditions due to a favorable thermodynamic redox potential connected to proton uptake. In contrast, oxidation reactions such as water oxidation are thermodynamically optimal at basic pH as they typically involve proton release. Therefore, it is desirable to perform the reduction and oxidation reaction in different compartments while connecting the compartments electronically. , under license number 5911880595918 from The American Association for the Advancement of Science), e) Molecular wire embedded in a 2-nm-thick SiO2 membrane enables electron flow from microbial catalysts to the inorganic anode. The system we report here uses a very simple, symmetric oligoaromatic molecular wire [1] 2+ that spans across the lipid bilayer membrane of artificial vesicles and effectively transfers electrons across the membrane under both inert and aerated conditions (Figure and). The design principle of [1] 2+ matches the one for membrane-spanning molecules, having a central hydrophobic region and two terminal hydrophilic groups. The distance between the terminal hydrophilic trimethylammonium groups is 3 nm and matches the thickness of the membrane to avoid destabilization of the membrane. Interaction with visible light is ensured via the benzothiadiazole at its center. Hydrophobicity is maintained by adding fluorene to its core. The rigid oligoaromatic design of the transmembrane molecular wire [1] 2+ has the potential for light-driven electron transfer in a more rigid polymer-based material, which will be relevant for the technological scale-up process. As electron transfer does not rely on diffusion within the membrane, it will be possible to transfer electrons in an environment like a polymer-based membrane.