Two-photon polymerization for biological applications
Alexander K. Nguyen and Roger J. Narayan
Materials Today Volume 20,Number 6 July/August 2017
UNC/NCSU Joint Department of Biomedical Engineering, North Carolina State University, Raleigh, NC 27695-7115, USA
https://doi.org/10.1016/j.mattod.2017.06.004
Two-photon polymerization (2PP) leverages the two-photon absorption (TPA) of near-infrared (NIR) radiation for additive manufacturing with sub-diffraction limit resolution within the bulk of a photosensitive material. This technology draws heavily on photosensitive polymers from the microelectronics industry, which were not optimized for TPA or for biocompatibility. 2PP with sub 100 nm resolution has been repeatedly demonstrated; however, this level of fabrication resolution comes at the expense of long fabrication times. Manufacturing of medical devices beyond surface texturing would be prohibitively slow using the current state of the art 2PP technology. Current research intoTPA-sensitivephotopolymerswithgoodbiocompatibilityandholographicprojectionsusingspatial light modulators address current technological limitations by providing materials specifically formulated for biological applications and by making better use of available laser power for applications in which nanoscale resolution is not required.
Optical setup of a femtosecond laser imaging and microfabrication system, which is capable of fluorescence lifetime imaging microscopy. Reprinted from Ref.