Genesis of a Horizontal Electric Field within the Lipid Bilayer: A Bilayer-Embedded Actuation Platform
The electric field of biological membranes has long been treated as a one-dimensional quantity, defined solely by the component normal to the bilayer (E_VERT). Here, we present a bioelectronic platform that enables controlled generation of a horizontal electric field within the hydrophobic core of a lipid bilayer (E_HORZ). The device incorporates micrometer-scale electrodes embedded within the bilayer torus, allowing sustained E_HORZ actuation. Applied E_HORZ selectively and reversibly accelerates slow inactivation of a voltage-gated potassium channel while leaving activation essentially unchanged. Physical considerations further indicate that E_HORZ arises naturally wherever membrane potential varies spatially, including at action potential wavefronts, suggesting broader physiological relevance. This platform provides experimental access to vector-resolved membrane electric fields and establishes a generalizable strategy for multidirectional electrical control of soft-matter biointerfaces.