Radiopaque Resists for Two-Photon Lithography To Enable Submicron 3D Imaging of Polymer Parts via X-ray Computed Tomography
[1];
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Materials Engineering Division, Materials Science Division
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Materials Engineering Division
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Materials Science Division
Two-photon lithography (TPL) is a high-resolution additive manufacturing (AM) technique capable of producing arbitrarily complex three-dimensional (3D) microstructures with features 2–3 orders of magnitude finer than human hair. This process finds numerous applications as a direct route toward the fabrication of novel optical and mechanical metamaterials, miniaturized optics, microfluidics, biological scaffolds, and various other intricate 3D parts. As TPL matures, metrology and inspection become a crucial step in the manufacturing process to ensure that the geometric form of the end product meets design specifications. X-ray-based computed tomography (CT) is a nondestructive technique that can provide this inspection capability for the evaluation of complex internal 3D structure. However, polymeric photoresists commonly used for TPL, as well as other forms of stereolithography, poorly attenuate X-rays due to the low atomic number (Z) of their constituent elements and therefore appear relatively transparent during imaging. We present the development of optically clear yet radiopaque photoresists for enhanced contrast under X-ray CT. We have synthesized iodinated acrylate monomers to formulate high-Z photoresist materials that are capable of forming 3D microstructures with sub-150 nm features. In addition, we have developed a formulation protocol to match the refractive index of the photoresists to the immersion medium of the objective lens so as to enable dip-in laser lithography, a direct laser writing technique for producing millimeter-tall structures. Our radiopaque photopolymer then resists increase X-ray attenuation by a factor of more than 10 times without sacrificing the sub-150 nm feature resolution or the millimeter-scale part height. Thus, our resists can successfully replace existing photopolymers to generate AM parts that are suitable for inspection via X-ray CT. By providing the “feedstock” for radiopaque AM parts, our resist formulation is expected to play a critical role in enabling fabrication of functional polymer parts to tight design tolerances.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC52-07NA27344; AC02-05CH11231
- OSTI ID:
- 1417282
- Report Number(s):
- LLNL-JRNL-732780; TRN: US1801019
- Journal Information:
- ACS Applied Materials and Interfaces, Vol. 10, Issue 1; ISSN 1944-8244
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
High‐Speed Direct Laser Writing of Silver Nanostructures via Two‐Photon Reduction
|
journal | August 2019 |
Conjugated Carbazole-Based Schiff Bases as Photoinitiators: From Facile Synthesis to Efficient Two-Photon Polymerization
|
journal | October 2018 |
Scalable submicrometer additive manufacturing
|
journal | October 2019 |
Similar Records
Preparing for the Next Generation of EUV Lithography at the Center for X-ray Optics
Instrumentation for Microfabrication with Deep X-ray Lithography