The present invention relates to detachment mechanisms for delivering and releasing implantable devices into a body lumen. According to certain aspects, systems of the invention include a junction that couples an implantable device to a delivery member. The junction includes an anodic portion and a cathodic portion galvanically coupled to the anodic portion such that the anodic portion corrodes when exposed to an electrolytic fluid, thereby detaching the implantable device from the delivery member without application of energy from an external power source.