Hierarchical dendrite-inspired organic bioelectronic interfaces for neuronal integration

Brain-machine interfaces rely on intimate electrical communication between living neurons and artificial materials, yet conventional electrode architectures remain structurally different to neuronal tissue, limiting stable cell-electrode coupling and long-term recording. Although conducting polymers and microstructured interfaces have individually improved the electrochemical and biological properties of neural electrodes, integrating neuromimetic architecture with electrically active organic materials to direct neuron-electrode interactions has remained challenging. Here we engineer dendrite-inspired organic microelectrodes by programming the self-assembly of conducting polymer fibers directly on microelectrode arrays. By controlling the electrodeposition process, we generate hierarchical architectures that emulate key stages of dendritic development while preserving the relevant electrochemical properties of conducting polymers. These bioinspired interfaces promote nanoscale membrane conformability, reduce the neuron-electrode cleft, and induce localized membrane engulfment of the electrode structures. The enhanced structural integration is accompanied by increased synaptic protein expression and neuronal excitability within mature primary cortical networks. Furthermore, the dendritic electrodes enable localized laser-assisted optoporation, providing transient intracellular electrophysiological access while maintaining extracellular recording functionality.