A shoe-box-sized 3D laser nanoprinter based on two-step absorption

Abstract

State-of-the-art commercially available 3D laser micro-and nanoprinters using polymeric photoresists based on two-or multi-photon absorption rely on high-power pico-or femtosecond lasers, leading to fairly large and expensive instruments. Lately, we have introduced photoresists based on two-step absorption instead of two-photon absorption, allowing for the use of small and inexpensive continuous-wave 405 nm wavelength GaN semiconductor laser diodes with light-output powers below 1 mW. Here, using the identical photoresist system and similar laser diodes, we report on the design, construction, and characterization of a 3D laser nanoprinter that fits into a shoe box. This shoe box contains all optical components, namely the mounted laser, the collimation-and beam-shaping optics, a miniature MEMS xy-scanner, a tube lens, the focusing microscope objective lens (NA=1.4, 100× magnification), a piezo slip-stick zstage, the sample holder, a camera monitoring system, LED sample illumination, as well as the miniaturized control electronics employing a microcontroller. We present a gallery of example 3D structures printed with this instrument. We achieve about 100 nm lateral spatial resolution and focus scan speeds of about 1 mm/s. Potentially, our shoe-box-sized system can be made orders of magnitude less expensive than today's commercial systems.