Seamless encapsulation for stable storage of an active material and its controlled release when needed are the ultimate targets of all encapsulation-related technologies. However, seamless encapsulation often limits the effects of external stimuli for triggering release. Thus, systems in which release is triggered by ultrasonic waves have usually employed relatively weak encapsulation systems such as liposomes. Herein, we developed a novel triggering mechanism (uncorking) that combines sonication triggering and seamless stable encapsulation. Core-shell nanofibers were chosen as encapsulation systems and silica nanoparticles were developed as corks on the surfaces of the nanofibers. The nanoparticles were attached on the surfaces of nanofibers by a combination method of electrospinning and electrospraying, and subsequent solvent-vapor annealing embedded the nanoparticles, resulting in the formation of corks. Annealing for 30 min gave half-embedded nanoparticles, 50% of which could be uncorked by sonication for 30 min. Successful uncorking triggered zero-order release from the core of the nanofibers. Uncorking left nanocraters on the surface that acted as diffusion paths for release. This novel uncorking strategy for release will enable smart release control of nanofibers and textiles for various future applications. (C) 2015 Elsevier B.V. All rights reserved.