Low-Voltage Continuous Electrospinning Patterning

Abstract

Electrospinning is a versatile technique for the construction of microfibrous and nanofibrous structures with considerable potential in applications ranging from textile manufacturing to tissue engineering scaffolds. In the simplest form, electrospinning uses a high voltage of tens of thousands volts to draw out ultrafine polymer fibers over a large distance. However, the high voltage limits the flexible combination of material selection, deposition substrate, and control of patterns. Prior studies show that by performing electrospinning with a well-defined "near-field" condition, the operation voltage can be decreased to the kilovolt range, and further enable more precise patterning of fibril structures on a planar surface. In this work, by using solution dependent "initiators", we demonstrate a further lowering of voltage with an ultralow voltage continuous electrospinning patterning (LEP) technique, which reduces the applied voltage threshold to as low as 50 V, simultaneously permitting direct fiber patterning. The versatility of LEP is shown using a wide range of combination of polymer and solvent systems for thermoplastics and biopolymers. Novel functionalities are also incorporated when a low voltage mode is used in place of a high voltage mode, such as direct printing of living bacteria; the construction of suspended single fibers and membrane networks. The LEP technique reported here should open up new avenues in the patterning of bioelements and free-form nano- to microscale fibrous structures.

Three‐dimensional electrospun nanofibrous scaffolds for bone tissue engineering

“…Recently, a hybrid system combining 3D printing and electrospinning has been developed, which is referred as electrohydrodynamic printing and can construct a 3D nanofibrous scaffold with a controlled structure at nanoscale (Figure d) (Zhang, He, Li, Xu, & Li, ). The main methods involved in electrohydrodynamic printing include the use of additional devices to improve jet focusing (Lee, Jang, Oh, Jeong, & Cho, ; Lee, Lee, Jang, Jeong, & Cho, ), near‐field electrospinning (Li et al, ), and melt electrospinning (He, Xia, & Li, ; Muerza‐Cascante et al, ).…”

Large‐Scale Direct‐Writing of Aligned Nanofibers for Flexible Electronics

“…Since their plenty of available binding sites for biological recognition element immobilization, fast mass transfer rates, and facile surface functionalization of various groups, electrospun nanofibers have demonstrated rather a high potential in biological applications, including biosensors, drug delivery, water treatment, or tissue engineering . Precise deposition of fiber arrays is essential in determining the functionalities of biomimetics devices and provides great versatility for incorporation into multiplexed, portable, wearable, and even implantable medical devices …”

“…Micro/nanofluidic is a key issue technology for biological analysis and basic cell biology, and rapid, high‐efficiency and cost‐effective fabrication of complex footpaths with a resolution in micrometer/nanoscale are highly demanded . As electrospun fibers can serve as sacrificial templates on a variety of soft, transparent, flexible, and biocompatible polymers as shown in Figure a, EHD direct‐writing provides a rather facile and low‐cost way to fabricate large‐scale well‐defined channels that can be easily integrated into lab‐on‐chip devices, replacing the complex and expensive lithographic techniques . By selectively washing away the electrospun fibers, Vempati et al had successfully fabricated aligned microtubes/microchannels onto a self‐standing flexible polymer film, showing great potential for tissue engineering.…”

“…a) Schematic diagram of low‐voltage EHD direct‐writing and the corresponding biological applications such as microfluidic footpaths, printing of bacteria and protein, etc. Reproduced with permission . Copyright 2016, American Chemical Society.…”

“…This achievement is a significant step toward fabrication of brain‐inspired electronic devices and presented important inspiration for the development of high‐density and soft brain‐inspired computational systems with low‐power consumption. By adopting a low‐voltage electrospinning patterning, Li et al had realized the direct printing of living bacteria and protein on a range of substrates, from conducting to insulating in nature, and from hydrogels to solids as well. If other novel nozzles such as multi‐nozzle were introduced to control fiber morphology, perhaps much more science‐fiction biological electronic devices would be created out to further broaden the nanofiber‐based future electronics.…”