Nanofibrous patterns by direct electrospinning of nanofibers onto topographically structured non-conductive substrates

Abstract

Patterning of electrospun nanofibers has recently attracted much attention for its usefulness in a wide range of applications. This paper reports on the generation of spatially defined nanofibrous patterns by direct deposition of electrospun nanofibers onto a variety of insulating substrates. It was found that topographical features of different non-conducting substrates could be readily replicated by the electrospun nanofibers of interest. To elucidate the underlying mechanism of nanofiber patterning, we have systematically studied the effects of surface topography of non-conducting substrates (in particular protrusions) on the nanofiber deposition and assembly. Results from experiments and electric field simulation indicated that under a strong electric field the insulating substrates can be polarized, which could consequently affect the distribution of the original electric field. For particular non-conductive substrates with small mesh sizes or sufficient thickness, surface topography of the dielectric substrate may play a key role in determining the deposition and the arrangement of electrospun fibers. In addition, parameters that could influence the fineness of nanofibrous patterns have also been investigated. This contribution is believed to warrant further scientific understanding of the patterning mechanism of electrospun nanofibers, and to allow for design of specific and complex non-conductive substrate collectors for easy generation of patterned nanofibrous architectures, applicable in a variety of areas such as tissue engineering scaffolds and optoelectronic displays.

Nerve Guidance Conduits from Aligned Nanofibers: Improvement of Nerve Regeneration through Longitudinal Nanogrooves on a Fiber Surface

“…channels formed by aligned nanofibers or micropatterned films) and chemical/biological agents (i.e., growth factors) facilitate cell adhesion and differentiation. [4][5][6][7][8][9][10][11][12] 2 Nanofibers, mostly produced by an electrospinning technique, show great potential for NGC applications, since they have small diameter, large surface-to-volume ratio, and a similar morphology to native extracellular matrices. 13 NGCs with well-controlled nanofiber alignment structure is highly desirable.…”

Fabrication of fibrous patterned architectures with controlled deposition and multidirectional alignment

“…Although it is possible to generate patterned architectures with the fixed ground electrodes, it is obvious from the optical images that the alignment of fibers in the patterns improved significantly when the electrodes' activation was switched from one location to another. This resulted in the concentration of electric field between the active electrodes . In addition, because of the altering potentials between adjacent electrodes in short duration, the charged fibers were forcibly driven from one location to another.…”

“…The phenomena might be explained with the electrostatic field patterns and strengths. When an insulating air gap is introduced between the collector electrodes, it modifies the pattern of external electrical field . It is reported that the electrical field strength is equally distributed among the present (active) electrodes and has higher magnitude toward them.…”

Three‐dimensional electrospun micropatterned cellulose acetate nanofiber surfaces with tunable wettability

“…Recently, Zhao et al . have studied the influence of insulating templates on electrospun nanofibrous mats . The deposition of the fibers was found to depend on the opening size of the templates .…”

“…This approach has enabled nanofibers to be preferentially directed towards the protrusions of a conductive template since they possess higher charge density. Alternatively, patterned fibrous mats have also been fabricated using easily available non‐conductive templates and by placing a thin layer of non‐conductive material over a conductive and patterned surface …”