Hybrid Electrospinning Printing for Nanofiber Self-Supporting 3D Microfluidic Devices

Micro/nano-devices with multi-level structure constructed via photo-curing 3D printing techniques had inherent defects including the sacrificial layer clogging caused by the micro/nano-scale maze effect of fluid and the liquid tension-induced capillary collapse. Moreover, movable film structures with poor elasticity were susceptible to cracking and deformation, resulting in fluid leakage and structural failure. Here, we proposed a new principle and method for micro/nano-devices with nanofiber self-consistent 3D printing. The mechanism of spreading and penetration between nanofibers and high viscosity fluids were investigated. Due to the behavior of viscosity, capillary force and surface tension, the high-viscosity fluid is suspended in the surface layer of the nanofiber membrane, expanded and permeated in the micro/nano-pores to form movable film structure. Nanofiber under the surface layer still maintains microporosity, which plays a role of supporting the surface movable film and local interconnection. Inspired from this, a nanofiber movable film-microcavity microfluidic device including hollow microfluidic structure and nanofiber self-consistent microfluidic structure were fabricated. A LED light was applied to verify the switching performance of the valve. This method exhibited a simple manufacturing process to design highly flexible structures, representing a great potential for promoting the mass production and integrated manufacturing of these devices.