Mesoscale laser 3D printing

Abstract

3D meso scale structures that can reach up to centimeters in overall size but retain micro-or nano-features, proved to be promising in various science fields ranging from micro-mechanical metamaterials to photonics and bio-medical scaffolds. In this work, we present synchronization of the linear and galvanometric scanners for efficient femtosecond 3D optical printing of objects at the meso-scale (from sub-µm to sub-cm spanning five orders of magnitude). In such configuration, the linear stages provide stitch-free structuring at nearly limitless (up to tens-of-cm) working area, while galvo-scanners allow achieving translation velocities in the range of mm/s-cm/s without sacrificing nano-scale positioning accuracy and preserving the undistorted shape of the final print. The principle behind this approach is demonstrated, proving its inherent advantages in comparison to separate use of only linear stages or scanners. The printing rate is calculated in terms of voxels/s, showcasing the capability to maintain an optimal feature size while increasing throughput. Full capabilities of this approach are demonstrated by fabricating structures that reach millimeters in size but still retain sub-µm features: scaffolds for cell growth, microlenses, and photonic crystals. All this is combined into a benchmark structure: a meso-butterfly. Provided results show that synchronization of two scan modes is crucial for the end goal of industrial-scale implementation of this technology and makes the laser printing well aligned with similar approaches in nanofabrication by electron and ion beams.

3D Printing Customized Optical Lens in Minutes

“…Finally, at 200-fold improved printed speed, we have successfully demonstrated 3D printing of 3 mm high optical lens in 2 min 11 s (Video S1, Supporting Information), which represents a significant improvement in comparing with the previously reported work that takes hours to 3D printing of lens of similar size. [10] Comparing with the fastest fabricating speed in femtosecond 3D printing technique being recently reported, [9] in which the volumetric speed and voxel-rate speed can be calculated as 5667 µm 3 s −1 and 3.09 × 10 4 voxel s −1 respectively, the printing speed reported here is still 2.38 × 10 5 -fold faster volumetrically or 100-fold faster in voxel rate.…”

“…[7] However, due to the intrinsic point-by-point scanning nature, fabricating millimeter-sized lens via sequential addition of 100 nm voxels can be rather time consuming and expensive. [8,9] To mitigate the speed-accuracy tradeoff underlying the 3D printing process, we previously reported method for high-speed 3D printing of optical lens via the combination of projection micro-stereolithography (PµSL) process, grayscale exposure, and meniscus coating. [10] PµSL employs a dynamic mask to photopolymerize a 2D layer in each exposure, [11] which parallelizes the point-by-point scanning process with significantly improved printing speed.…”

Polymers for Regenerative Medicine Structures Made via Multiphoton 3D Lithography

“…In the case of oscillators, such pulses can be extremely short (sub-100 fs) and, in turn, have relatively broad spectrum width. Furthermore, several laser harmonics might be used in one 3DLL setup [6]. Therefore, optics in the setup have to be able to sustain all of the relevant harmonics with respective spectral widths.…”

“…However, due to the high inertia of the stages, distortions might appear in more complex cases also creating a limitation. The solution to these problems is synchronization of galvanometric scanners and linear stages allowing to achieve stitch-free printing with superb quality of complex 3D shapes at high translation velocities [6]. As a result, it was already used in RM-related research [16].…”

“…The idea behind this technology is to sharply focus a laser (in most cases, femtosecond (fs)) beam into a special photoactive material initiating highly localized photomodification via multiphoton absorption and/or other related nonlinear light-matter interactions [2]. It combines resolution below the diffraction limit [3,4], virtually no limitations to the 3D architecture of an object with the structuring process not bound to layer-by-layer printing [5,6], and a huge variety of the materials that could be used [7,8]. Due to this, it was used in numerous fields, which include photonics [9,10], microoptics [11,12], micromechanics [13,14], microfluidics [5,15], and biomedicine [16,17].…”