Finland: new method for forming 3D nanomaterials

Commercialisation opportunity

VTT Technical Research Centre of Finland, Tampere University of Technology and Nanofoot Finland Oy have developed a direct-write three-dimensional method for forming biomaterials. The technique enables fabrication of nano and micrometre scale structures for use in tissue engineering scaffolds.

The new process is based on the use of a visible light, ultra short pulse laser. When focused inside light-sensitive polymers the radiation causes  two photons to be absorbed simultaneously.

One of the advantages of this two-photon polymerisation process is that the fabrication occurs below the surface of liquid material and is confined only to the point of focus, whose diameter can be much less than 1 micrometre.

While conventional ultraviolet light induced polymerisation causes hardening of the material along the entire path of the UV-beam, thus making it impossible to form very small three-dimensional features, the two-photon polymerisation process forms the structure directly inside the liquid volume.

Highly accuracy biomaterial structures are needed for tissue engineering or cell culture platforms, because the structures have to follow the dimensions of the cultured cells.

To date, the smallest features achieved in this project have been about 700 nanometres wide. In contrast epithelial cells have a diameter of 11,000 to 12,000 nanometres, while viruses range ibetween 10 and 100 nanometres.

The fabricated structures can be made of biodegradable materials and are biocompatible. The process can also be utilised in manufacturing structures for other applications, for example, optical waveguides, photonic crystals, and microfluidic channels.

A further advantage of this process is the option of using an inexpensive, low-power laser. Other research groups have typically used very expensive femtosecond titanium-sapphire pulse lasers, while a much cheaper laser that produces longer, picoseconds width pulses has been used in the project.

The nanotechnology specialist Nanofoot Finland Oy is now looking to commercialise the process.