Emerging micro-additive manufacturing technologies enabled by novel optical methods

Abstract

This paper presents a comprehensive review of recent advances in micro-additive manufacturing enabled by novel optical methods with an emphasis on photopolymerization-based printing processes. Additive manufacturing, also known as three-dimensional (3D) printing, has become an important engineering solution to construct customized components or functional devices at low cost. As a green manufacturing technology, 3D printing has the advantages of high energy efficiency, low material consumption, and high precision. The rapid advancement of 3D printing technology has broadened its applications from laboratory research to industrial manufacturing. Generally, 3D objects to be printed are constructed digitally [e.g., via computer-aided design (CAD) programs] by connecting a 3D dot array, where a dot is defined as a voxel through mechanical, electrical, or optical means. The voxel size ranges from a few orders of magnitude of the wavelength of light to the sub-diffraction limit, achieved by material nonlinearity and precise power thresholding. In recent years, extensive research in optical additive manufacturing has led to various breakthroughs in quality, rate, and reproducibility. In this paper, we review various micro-3D printing techniques, including single-photon and two-photon processes, with a focus on innovative optical methods, e.g., ultrafast beam shaping, digital holography, and temporal focusing. We also review and compare recent technological advances in serial and parallel scanning systems from the perspectives of resolution, rate, and repeatability, where the strengths and weaknesses of different methods are discussed for both fundamental and industrial applications.

Surface Exposure Technology of Metal Powder Based on an Optically-Addressed Liquid Crystal Spatial Light Modulator

“…The manufacturing accuracy of metal powder laser AM is in the range of approximately 80-250 µm, which is lower than that of stereolithography [6][7][8]. Therefore, improving the printing accuracy is a crucial research area.…”

Combining one and two photon polymerization for accelerated high performance (3+1)D photonic integration

“…In DLW, a tightly focused laser spot is translated through a photoresin to form a solid inside the TPP process's reactive volume, which results in a sub-micron voxel 4 . In photonics, the DLW-TPP technique has been used to fabricate free-form and transformational components [5][6][7] , point-to-point photonic wire-bondings 8 , waveguides 9 , spatial-filters 10 , gradedindex lenses 11 and photonic components 12,13 . Simultaneously, this technique is advantageous for integrated photonic circuits 14,15 due to its ability to locally and dynamically modify optical properties on feature sizes below the Abbe resolution limit.…”

Aligned Stacking of Nanopatterned 2D materials -- Towards 3D printing at atomic resolution

“…Methods for generating arbitrary 3D structures are commonly referred to as "3D printing". Also in this area, the minimum feature sizes that can be defined are continuously shrinking as new approaches are invented and developed, although the 3D resolution is still larger than what can be achieved in planar structures [9][10][11][12][13][14]. Currently, optical methods can be pushed to a resolution of about 100nm [12].…”

“…Also in this area, the minimum feature sizes that can be defined are continuously shrinking as new approaches are invented and developed, although the 3D resolution is still larger than what can be achieved in planar structures [9][10][11][12][13][14]. Currently, optical methods can be pushed to a resolution of about 100nm [12]. Electron-or ion-beam induced deposition can reach a resolution in the nanometer-range for planar structures on thin membranes [15], but generally the resolution is limited by the interaction volume rather than the beam diameter, which also depends on the target geometry, and for 3D structures is typically in the range of tens of nanometers [11].…”