In the electrospinning process, a modified parallel electrode method (MPEM), conducted by placing a positively charged ring between the needle and the parallel electrode collector, was used to fabricate highly aligned carbon nanotubes/polyacrylonitrile (CNTs/PAN) composite nanofibers. Characterizations of the samples—such as morphology, the degree of alignment, and mechanical and conductive properties—were investigated by a combination of scanning electron microscopy (SEM), transmission electron microscopy (TEM), universal testing machine, high-resistance meter, and other methods. The results showed the MPEM could improve the alignment and uniformity of electrospun CNTs/PAN composite nanofibers, and enhance their mechanical and conductive properties. This meant the successful preparation of highly aligned CNT-reinforced PAN nanofibers with enhanced physical properties, suggesting their potential application in appliances and communication areas.

Three dimensional printing (3DP), or additive manufacturing, is an exponentially growing process in the fabrication of various technologies with applications in sectors such as electronics, biomedical, pharmaceutical and tissue engineering. Micro and nano scale printing is encouraging the innovation of the aforementioned sectors, due to the ability to control design, material and chemical properties at a highly precise level, which is advantageous in creating a high surface area to volume ratio and altering the overall products’ mechanical and physical properties. In this review, micro/-nano printing technology, mainly related to lithography, inkjet and electrohydrodynamic (EHD) printing and their biomedical and electronic applications will be discussed. The current limitations to micro/-nano printing methods will be examined, covering the difficulty in achieving controlled structures at the miniscule micro and nano scale required for specific applications.

A modified parallel electrode method (MPEM), conducted by placing a positively charged ring between the needle and the paralleled electrode collector, was presented to fabricate aligned polyacrylonitrile/graphene (PAN/Gr) composite nanofibers (CNFs) with nanopores in an electrospinning progress. Two kinds of solvents and one kind of nanoparticle were used to generate pores on composite nanofibers. The spinning parameters, such as the concentration of solute and solvent, spinning voltage and spinning distance were discussed, and the optimal parameters were determined. Characterizations of the aligned CNFs with nanopores were investigated by scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), high-resistance meter, and other methods. The results showed that graphene (Gr) nanoparticles were successfully introduced into aligned CNFs with nanopores and almost aligned along the axis of the CNFs. The MPEM method could make hydrophobic materials more hydrophobic, and improve the alignment degree and conductive properties of electrospun-aligned CNFs with nanopores. Moreover, the carbonized CNFs with nanopores, used as an electrode material, had a smaller charge-transfer resistance, suggesting potential application in electrochemical areas and electron devices.

The aligned polylactic acid (PLA) porous fibers have a feature of high specific surface area, special structure and excellent biological properties, which are appropriate as the material of tissue engineering. Simultaneously, the aligned PLA porous fibers are beneficial to the orientation of tissue cells, so it is expected to become a good biological scaffold material. The solvent was composed by of chloroform(CF) and N,N-dimethylformamide (DMF) of which the ratio was 9:1, and the concentration of PLA was eight percent. The obtained fibers were observed under the scanning electron microscope and indicated that they were porous and paralleled.