Simulation of biological ionic channels by technology computer-aided design

Technology computer-aided design (TCAD) tools for semiconductor device simulation give a self-consistent solution of the equations of Poisson and of current continuity, or Boltzmann-type equations, including fixed and mobile charges of either sign in various dielectrics. Ionic channels in biological membranes exhibit many properties that can be described by the same equations. We show that well developed and commercially available TCAD tools can be used, after certain simple scaling transformations, to simulate the ionic channel conduction process and to test ideas about the static and dynamic response of these channels. We attempt to demonstrate in this paper the availability and the use of commercial and academic research tools of silicon TCAD for the simulation of electrical conduction in biological ion channels. We discuss two classes of numerical codes, continuum and particle simulation tools.