Nanowire electrode

Nanowire electrodes replace a flat contact with a dense array of vertical, high-aspect-ratio wires (silicon, metal, oxide, or III-V semiconductor). The three-dimensional geometry multiplies electrochemical surface area, lowering impedance, while the protruding tips can engage individual cells, tighten the electrode-membrane seal, and in some designs penetrate or fuse with the membrane for intracellular-quality access.

They sit at the intersection of impedance engineering and tight coupling: as passive contacts they behave like any high-surface-area coating, but as cell-penetrating structures (hollow nanowires or nanostraws) they enable transient intracellular recording and even molecular delivery. Chronic in-vivo use is limited by fragility, unknown long-term biocompatibility of high-aspect-ratio nanostructures, and the difficulty of maintaining a penetrating interface as tissue moves.