Nanoelectrode Nerve Stimulation Simulator (2D)

This 2D companion to the 3D nanoelectrode-array engine strips the same real point-source stimulation physics down to a single electrode and a single schematic axon so the underlying mechanism is easy to see. A nanoelectrode tip near the axon is modelled as a point current source in tissue of conductivity σ, producing an extracellular voltage field V(r) = I/(4πσr) that falls off smoothly with distance. Every point along the axon has its own randomised activation threshold, and — via Lapicque's strength-duration law, the same τ_chronaxie ≈ 200 µs used in the 3D array — that threshold rises for shorter pulses. Wherever the local field crosses threshold the axon genuinely fires, and a real action potential propagates outward from the activated zone in both directions at a fixed conduction velocity. Drag the electrode along the axon, move it closer or farther away, and sweep current amplitude and pulse width to watch the recruited zone and its firing behaviour respond exactly as the strength-duration relationship predicts.