  In an ongoing debate on the physical nature of the action potential, one
group adheres to the electrical model of Hodgkin and Huxley, while the other
describes the action potential as a non-linear acoustic pulse propagating
within an interface near a transition. However, despite remarkable
similarities, acoustics remains a non-intuitive mechanism for action potentials
for the following reason. While acoustic pulses are typically associated with
the propagation of density, pressure and temperature variation, action
potentials are most commonly measured electrically. Here, we show that this
discrepancy is lifted upon considering the electrical and chemical aspects of
the interface, in addition to its mechanical properties. Specifically, we
demonstrate how electrical and pH aspects of acoustic pulses emerge from an
idealized description of the lipid interface, which is based on classical
physical principles and contains no fit parameters. The pulses that emerge from
the model show striking similarities to action potentials not only in
qualitative shape and scales (time, velocity and voltage), but also demonstrate
saturation of amplitude and annihilation upon collision.
