An electrospinning method for the production of continuous and highly aligned nanofibers and quasi-isotropic nanofiber preforms
Electrospinning of polymers from the melt or solution is a simple but versatile technique to produce nano and microfibers, non-woven mats and twisted yarn. These polymeric fibers or mats can be used per se or heat treated to obtain inorganic fibers (carbon or even titania). For composite applications, a key requirement is fiber alignment and compact packing to achieve desired thickness and mechanical strength.
There are techniques capable to produce highly aligned nanofiber preforms, but there are no industrial processes to produce those continuously on a large scale as sheets, prepregs or ribbons for structural and device applications.
At the same time, to improve the mechanical strength of those prefroms, the gaps between fibers should be minimised, which is not possible with traditional electrospinning, where the required strength of the preforms is only achieved by increasing their thickness.
The ideal way to improve the strength of the preforms in to deposit the nanofibers in a quasi-isotropic manner (zero, ninety and forty five degree orientations), however, continuous and inexpensive production of such preforms or mats has not been successfully demonstrated until now.
The revolutionary electrospinning technology and equipment developed by researchers from the University of Birmingham is capable of: (i) producing continuous and aligned nanofibers on a demountable (or rolling) substrate; (ii) tight packing of aligned fibers on the substrate; (iii) depositing fibers continuously at zero and/or any angle between zero and ninety degrees – in other words, quasi-isotropic fiber preforms can be manufactured without a need for layer-by-layer lamination.
- Continuous: The equipment allows non-stop production of highly aligned fibers or fiber mats;
- Robust: Generated fibers can be easily removed from the substrate without loss of alignment;
- Tuneable: The equipment allows quick and easy adjustment of the deposition angle;
- Inexpensive: Technology can be easily incorporated into existing laboratory and mass-scale electrospinning set-ups;
- Unique: Technology allows multiple angle aligned deposition for continuous fabrication of quasi-isotropic materials and fiber mats;
- Wide range: The angle of fiber alignment in the fiber mats can be any from 0 to 180o.
- User-friendly:The equipment does not require any additional specific training to operate.
- Filtration and separation materials
- Wound dressing
- Tissue scaffolds
- Sensors and light guides
- Smart fabric
- Cellulose-based packaging materials
- Carbon fiber preforms
- Flexible electronics