Field guide: technological advances in electrospinning of nanofibres
A better understanding of the electric field profile and its effect on the electrospinning jet together with upgrades in mechanical set-ups are allowing researchers to fabricate ever more elaborate structures based on a stream of nanofibre. Writing in our partner journal Science and Technology of Advanced Materials, Wee-Eong Teo, Ryuji Inai and Seeram Ramakrishna track the developments.
Over the last decade, advances in electrospinning have seen nanofibrous arrangements evolve from a nonwoven form to yarn, 3D assemblies and patterned structures. The process has emerged as a popular nanotechnology since the late 1990s owing to the ease of fabricating nanofibres from a wide selection of materials and has become an important route to learning more about the properties of materials in nanofibre form.
Future advances in electrospinning are likely to be driven by applications that require specialized nanofibre chemistry and structure, multifunctional hierarchical organizations and their scaling to industrial production.
Tuning the technology
Techniques such as ultraviolet cutting, chemical fragmentation and ion etching have been developed to address the preference for short fibres in noninvasive surgical and solar-energy applications. And owing to the high surface area of nanofibres, interesting properties and improved device performance can be expected.
From a commercial perspective, the application of electrospun nanofibres will be in high-performance or high-value-added products.
The ability to precisely control fibre deposition to form patterns using electrospinning has the potential to significantly expand the application of this technique and improve device performance. For example, signals from sensors made of nanofibres can be quickly routed to a receiver.
Although conductive nanofibres have been fabricated using electrospinning, the chaotic nature of the deposition process seems incompatible with the high accuracy required for the fabrication of electronic devices. Nevertheless, electrospinning does offer several advantages over existing methods. First, it is a relatively fast process and can be used for the rapid prototyping of nanofibrous devices. Second, it is very simple to obtain fibres with diameters smaller than 500 nm with this technique. Third, the nanofibre is continuous, which reduces the likelihood of a breakage in the connection compared with ink-jet printing methods.