D. Jao, V. Beachley
Keywords: nanofibers, alignment, biomedical
Summary:The device is an automated set-up for drawing single nanofibers or multi-filament arrays of nanofibers from polymer solutions or melts using a rotating track system which can be brushless, treadless, embedded with brushes, or incorporate patterned treads. Fibers are continuously spun by draw/contact spinning between two tracks; the automated touch track system can produce continuously aligned single filament nanofibers or arrays of nanofibers along a single linear axis (not a circular axis) with the addition or option of a secondary post-drawing step at the collector stage. The automated touch track system has two tracks which are adjustable and can be angled or run parallel so polymer solutions and melts can come in contact and be stretched and elongated over a wide range of fiber diameters. When the rotating track with or without brushes with polymer solution picked up from a reservoir touches the surface of a second track, many fibers are simultaneously produced in minutes. In this system, the polymer solution is dropped out from a needle of a syringe pump onto a patterned or non-patterned track or carried up by embedded brushes from a reservoir, it then comes in contact with the second track, where the polymer droplet is distributed and drawn forming a liquid polymer bridge. As the two tracks proceed down the belt driven system (by DC motors, NEMA stepper motors or by hand), simultaneously in one direction, the polymer is stretched allowing the fiber chains to be elongated and aligned in one direction. The track method can easily scaled-up by using an array of embedded brushes on the track composed of numerous filaments or an array of patterned treads on the track. The track system can be used with all kinds of polymeric materials (polymer melts and solutions), and biopolymers (protein materials), and polymer composite materials. Owing to the simplicity of the method, the device can be used in wide variety of fields: Aerospace, biomedical, cosmetics, healthcare, electronics, infrastructure, etc... The spinning device is inexpensive and straightforward with interchangeable tracks, and the track can be disposable or lined as a single-use device for bioengineering labs and health care providers. Using this system, the automated touch track system can produced nanofiber from a wide variety of polymers (ex. PAN, PCL, PEO, PEDOT:PSS, PVAc, PVDF, nylon, para-aramid, telfon nanofibers, etc...), biopolymers (ex. Silk fibroin, collagen, zein, soy, peanut, etc...), DNA, and polymeric carbohydrates (alginate, cellulose, lignin, etc...). The device could enable us to create a wound dressing out of biocompatible materials seed and grow stem cells on scaffolding for tissue engineering. Other examples include, but are not limited to, biosensors, filtration technologies, fibrous smart textiles, lightweight composites, and battery (fuel cell) technologies. The utility of this system is to manufacture submicron polymer fibers below the allowable limits of extrusion-based techniques. However, larger microscale fibers can be produced by this system as well.