Researchers of the Cluster of Excellence 3D Matter Made to Order Show How 3-dimensional Nanostructures Can Be Printed Using Compact Desktop Devices – Publication in Nature Photonics
Lasers in conventional laser printers for paper printouts are very small. 3D laser printers for 3-dimensional microstructures and nanostructures, by contrast, have required big and expensive laser systems so far. Researchers of Karlsruhe Institute of Technology (KIT) and the Heidelberg University now use another process for this purpose. Two-step absorption works with inexpensive and small, blue laser diodes. As a result, much smaller printers can be used. Work is reported in Nature Photonics. (DOI: 10.1038/s41566-021-00906-8)
Presently, laser printing is the method of choice for additive manufacture by 3D printing, as it offers the best spatial resolution of all methods and reaches an extremely high printing speed. In laser printing, a focused laser beam is directed towards a light-sensitive liquid. At the focal point, the laser light turns a switch in special molecules and triggers a chemical reaction. The reaction leads to the local hardening of the material. By moving the focal point, any 3D micro- and nanostructures can be produced. The chemical reaction is based on so-called two-photon absorption, meaning that two photons excite the molecule at the same time, which causes the desired chemical modification. However, this simultaneous excitation happens very rarely, which is why complex pulsed laser systems have to be applied, resulting in bigger dimensions of the laser printer.