Nanomanufacturing of large area carbon nanofibers using tube nozzle electrospinning (TNE), lithography and carbonization processes

This paper reports on the tube nozzle electrospinning (TNE) technique for the large scale production of electrospun nanofibers with a single plug-and-play unit to be added to the conventional electrospinning setup; lithographical micropatterning of the nanofibers; and carbonization of the patterned nanofibers. Nozzle architectures with diameters of 0.2mm and 0.5mm with 1mm and 0.5mm spacing are implemented and tested for nanofiber productivity, porosity, and uniformity. Electrospun SU8 nanofibers are achieved with no beads at an operating voltage of 10kV and a tip-collector-distance (TCD) of 7.5cm. Nanofiber morphologies are characterized with different operating conditions. The diameter of nanofibers ranges from 287nm to 566nm. Nanofibers with a porosity of 29.1% are accomplished with a single two minute electrospinning cycle and an average pore size of 0.31μm². The TNE approach incorporated with a microcontrolled stage produces a uniform deposition of electrospun SU8 nanofiber on a 6” × 8” collector substrate in a semi-automated process. Studies on nozzle diameter and spacing for maximum liquid throughput, porosity, and uniformity of deposited nanofibers are discussed. Lithographical patterning and carbonization of the electrospun nanofibers are performed as post electrospun processes to produce patterned carbon nanofibers.