NCLA have been involved in structuring and modifying the surface properties of materials to control interaction with fluids and living cells.

Expertise has been developed in single-step processes to generate micro- and nano-scale line patterns on surfaces using laser techniques. The technology is flexible in terms of the periodicity of the lines. It is possible to engineer the structures rapidly over a wide area (cm²) or to selectively pattern with very high resolution. Minor variations in the processes for linear patterning enable a range of more complex nano-scale structures such as bumps, pillars, and meshes.

This expertise has been applied to producing a laser–based micropatterned collagen micro-fibre scaffold to address the problem of repairing large nerve deficits in peripheral nerve injuries. This project was carried out in collaboration with the Network of Excellence for Functional Biomaterials (NFB) ( http://www.nfb.ie/). It was shown that the microstructured collagen fibre scaffolds caused a significant increase in aligned neurite outgrowth in vitro thus indicating an advantage in peripheral nerve repair. Following on from this study, the patterned fibres were inserted into a single channel polymer nerve conduit and transplanted into a rat sciatic nerve for a short term in vivo study. The addition of these structured fibres initially increased targeted nerve regeneration but the effects were lost at the end of the study due to scaffold inhibition.

These techniques could be applied to the following:-

• Biomedical devices/implants
  • improved cell/protein interactions
  • antifouling surfaces
  • drug loading/drug delivery
  • microfluidics/lab-on-a-chip
• Photonics
  • solar panels
  • plastic electronics
  • displays
• Tribology/lubrication
  • low friction surfaces
  • superhydrophobic surfaces
  • lubricant bearing surfaces

Micro-structures on a 50 µm biodegradable polymer fibre

Nano-mesh produced on polycarbonate (Mesh has a periodicity of approximately 160 nm)

Nano-pillar array produced on polycarbonate (Pillars have a periodicity of approximately 680 nm)