Optical 3D printing: bridging the gaps in the mesoscale

Abstract

Over the last decade, optical 3D printing has proved itself to be a flexible and capable approach in fabricating an increasing variety of functional structures. One of the main reasons why this technology has become so prominent is the fact that it allows the creation of objects in the mesoscale, where structure dimensions range from nanometers to centimeters. At this scale, the size and spatial configuration of produced single features start to influence the characteristics of the whole object, enabling an array of new, exotic and otherwise unachievable properties and structures (i.e. metamaterials). Here, we present the advantages of this technology in creating mesoscale structures in comparison to subtractive manufacturing techniques and to other branches of 3D printing. Differences between stereolithography, sintering, laser-induced forward transfer and femtosecond laser 3D multi-photon polymerization are highlighted. Attention is given to the discussion of applicable light sources, as well as to an ongoing analysis of the light–matter interaction mechanisms, as they determine the processable materials, required technological steps and the fidelity of feature sizes in fabricated patterns and workpieces. Optical 3D printing-enabled functional structures in micromechanics, medicine, microfluidics, micro-optics and photonics are discussed, with an emphasis on how this particular technology benefits advances in those fields. 4D printing, achieved by varying both the architecture and spatial material composition of the 3D structure, feature-size reduction via stimulated emission depletion-inspired nanolithography or thermal post-treatment, as well as plasmonic nanoparticle-polymer nanocomposites, are presented among examples of the newest trends in the development of this technology. Finally, an outlook is given, examining further scientific frontiers in the field as well as possibilities and challenges in transferring laboratory-level know-how to industrial-scale production.

Biocompatibility Evaluation and Enhancement of Elastomeric Coatings Made Using Table-Top Optical 3D Printer

“…The 3D femtosecond laser nanolithography could make sub-micrometer additions to the macro-structure of produced scaffolds [31], out of huge variety of different materials, including non-photosensitized [35,36] or fuctionalized [37] polymers. In essence, pairing of various processing techniques is a powerful way to offset most of the technological drawbacks and accentuate advantages [1,33]. For instance, 3D laser nanolithography is struggling to process elastic materials [14,38].…”

“…Recently, diverse 3D printing technologies have received a lot of attention in the areas of science and industry [1]. Differently from traditional processes of manufacturing, 3D printing allows computer aided manufacturing (CAM) of arbitrary geometry objects using computer aided design (CAD) models out of variety of materials with minimal fabrication costs.…”

Biocompatibility Evaluation and Enhancement of Elastomeric Coatings Made Using Table-top Optical 3D Printer

“…3D femtosecond laser nanolithography could make sub-micrometer additions to the macro-structure of produced scaffolds [23], out of huge variety of different materials, including non-photosensitized [27,28] or fuctionalized [29] polymers. In essence, pairing of various processing techniques is a powerful way to offset most of the technological drawbacks and accentuate advantages [1,25]. For instance, 3D laser nanolithography is struggling to process elastic materials [14,30] Peer-reviewed version available at Coatings 2020, 10, 254; doi:10.3390/coatings10030254…”

Mesoscale Laser 3D Printing

“…If the size of the object is further increased and exceed standard working area of high (1.4) NA objectives (up to 150 µm) stitching has to be introduced, further compromising the mechanical and optical qualities of the structure [20,21,23]. The working field can be increased few-fold by reducing NA, however, at the cost of printing resolution, as the voxels become larger and more elliptical [2].…”

“…Amidst all of this, 3D printing emerged as a new and powerful manufacturing tool of choice, as it provides nearly limitless structure geometries (within boundaries of resolution) and unmatched idea-to-object realisation rate. Optical 3D printing stands out amongst all the 3D printing techniques, as by changing the light source and its parameters a huge variety of different light-matter interaction regimes can be exploited for multi-dimensional free-form structuring [2]. The femtosecond (fs) laser-based 3D laser lithography (3DLL) is the most precise and versatile of those [3,4] and was used to great effect in fields ranging from micromechanics [5,6] and biomedicine [7,8], to integrated microoptics [9,10] and photonics [11,12].…”