Abstract: One aspect of the invention provides a method of producing a heterogeneous filament. The method includes applying pressure to a plurality of filament components to move the filament components into a common outlet channel. Another aspect of the invention provides a method of fabricating a scaffold. The method includes producing a plurality of filaments according to the methods described herein. Another aspect of the invention provides a scaffold produced according to the methods described herein. Another aspect of the invention provides a heterogeneous filament including a plurality of adjacent filament components. Another aspect of the invention provides a method of producing a droplet. The method includes: positioning a printing tip in proximity to a cross-linking liquid; applying pressure to one or more liquids to produce a droplet extending beyond outside of the printing tip; and contacting the droplet with the cross-linking liquid, thereby producing a droplet.

Abstract: One aspect of the invention provides a method of generating ultraviolet radiation. The method includes: introducing a mixture of nitrogen gas and helium gas into a dielectric barrier discharge device including a high voltage electrode and a ground electrode separated by a gap and a dielectric; and applying suitable electricity to the high voltage electrode, thereby generating ultraviolet radiation. Another aspect of the invention provides a plasma- and ultraviolet-generating nozzle including: a dielectric barrier discharge device; and a controller programmed to control flows of gas into the dielectric barrier discharge device and application of suitable electricity to the dielectric barrier discharge device to selectively generate either plasma or ultraviolet radiation. Another aspect of the invention provides a printing system including: a motion control system; and the plasma- and ultraviolet-generating nozzle as described herein coupled to the motion control system.

Abstract: The present invention relates to an integrated Assisting Cooling (AC) device, system and method for use with PED devices, allowing use of biopolymers having higher melting points in the fabrication of 3D scaffolds. The AC device cools the filament as it is extruding from the nozzle via low flow convective cooling. The AC device allows for cooling in the +/? direction of motion on an XY plane. The AC device elevates with the material delivery chamber. The AC device allows for scaffold fabrication at applied temperatures as high as about 250° C.

Abstract: The present invention relates to an integrated Assisting Cooling (AC) device, system and method for use with PED devices, allowing use of biopolymers having higher melting points in the fabrication of 3D scaffolds. The AC device cools the filament as it is extruding from the nozzle via low flow convective cooling. The AC device allows for cooling in the +/? direction of motion on an XY plane. The AC device elevates with the material delivery chamber. The AC device allows for scaffold fabrication at applied temperatures as high as about 250° C.