Fabrication of Bacteria Cell Arrays with Optical Vortex Laser-Induced Forward Transfer.

The optical vortex laser-induced forward transfer (OV-LIFT) technique enables the direct print of well-aligned dots with high spatial resolution and high positional accuracy. In this work, we demonstrate the direct printing of a 2-dimensional biomaterial (cyanobacteria cells) dot array using the OV-LIFT technique. The number of bacteria and size of the printed dots were controlled by simply adjusting the thickness of the donor film and the numerical aperture (NA) of focusing optics. The cell viability (∼90%) of cyanobacteria cells in the as-printed dots with OV-LIFT is significantly higher than that (>63%) achieved when using a conventional laser-induced forward transfer (LIFT) process. This demonstration highlights the viable application of OV-LIFT to the fabrication of freeform two- and/or three-dimensional printed microchannels for advanced applications such as light-harvesting devices based on biomaterials.