Credit: Wei Guo
(Up) Molecular structure of the selectivity filter of a KcsA potassium channel. Adjacent carbonyl rings exhibit a 27 degree rotation. Inspired by this structural feature, bi-layer graphene angstrom-pores with twisted carbonyl rings are designed as artificial potassium channel, and strict Na+/K+ selectivity is found therein. (Down) the evolution of electric-eel-mimetic ionic power generation.