Researchers develop laser-based ‘3D painting’ technique
A new laser based technique has been developed by researchers at the Vienna University of Technology which can fix molecules at exactly the right position in a three dimensional material.
Known as '3D photografting', the method could be used to grow biological tissue or create micro sensors and was created by two teams who had previously worked on 3d printing.
The method starts with a hydrogel – a material made of macromolecules, arranged in a loose meshwork. Specially selected molecules are introduced into the meshwork and then certain points are irradiated with a laser beam.
At the positions where the focused laser beam is most intense, a photochemically labile bond is broken, meaning highly reactive intermediates are created which locally attach to the hydrogel very quickly. The precision depends on the laser's lens system, with the teams claiming to obtain a resolution of 4µm.
"Much like an artist, placing colours at certain points of the canvas, we can place molecules in the hydrogel – but in three dimensions and with high precision", said Aleksandr Ovsianikov at the Vienna University of Technology.
The researchers say that depending on the application, different molecules can be used. As molecules can be positioned which attach to specific chemical substances and allow their detection, development of a microscopic three dimensional 'lab on a chip' could be a possibility.
