We present a microelectrofusion method for construction of fluidstate lipid bilayer networks of high geometrical complexity up to fully connected networks with genus ‫؍‬ 3 topology. Within networks, self-organizing branching nanotube architectures could be produced where intersections spontaneously arrange themselves into three-way junctions with an angle of 120°between each nanotube. Formation of branching nanotube networks appears to follow a minimum-bending energy algorithm that solves for pathway minimization. It is also demonstrated that materials can be injected into specific containers within a network by nanotubemediated transport of satellite vesicles having defined contents. Using a combination of microelectrofusion, spontaneous nanotube pattern formation, and satellite-vesicle injection, complex networks of containers and nanotubes can be produced for a range of applications in, for example, nanofluidics and artificial cell design. In addition, this electrofusion method allows integration of biological cells into lipid nanotube-vesicle networks.T he last two decades have witnessed a tremendous development in miniaturization of fluidic devices. The rapid progress in processing hard materials such as silicon and metals (1), polymeric materials such as polydimethylsiloxane (2), and parylenes (3) together with advancements in flow regulation (4, 5) have made it possible to manufacture complex chip structures for a wide range of applications, including chemical kinetics (6), computations (7), and chemical analysis (8).The ultimate fluidic device is one that can handle single molecules and colloid particles. Such devices require unprecedented control over transport and mixing behaviors, and to advance current fluidics into the single-molecule regime, we have to develop systems having physical dimensions in the nanometer scale. To create such devices, we can draw much knowledge from biological systems. For example, the Golgiendoplasmic reticulum network in eukaryotic cells has many attractive features for sorting and routing of single molecules, such as ultra-small-scale dimension, transport control, and capability to recognize different molecular species, and for performing chemical transformations in nanometer-sized compartments with minimal dilution. It is, however, extremely difficult to mimic these biological systems by using traditional microfabrication technologies and materials because of their small scale, complex geometries, and advanced topologies. Furthermore, it is difficult to implement traditional flow regulation methods on nanoscale systems.Our efforts are focused mainly on the development of soft microfabrication technologies for processing of fluid-state liquid crystalline bilayer membranes. These materials have unique mechanical properties allowing creation of nanoscale structures, such as spheres and tubes with extremely high curvatures (9). The geometry of such structures is governed by both selfassembling and self-organizing properties of the lipid membrane material and can be changed o...