Three-dimensional (3D) printing of metal components through powder bed fusion, material extrusion, and vat photopolymerization, has attracted interest continuously. Particularly, extrusion-based and photopolymerization-based processes employ metal particle-reinforced polymer matrix composites (PMCs) as raw materials. However, the resolution for extrusion-based printing is limited by the speed-accuracy tradeoff. In contrast, photopolymerization-based processes can significantly improve the printing resolution, but the filler loading of the PMC is typically low due to the critical requirement on raw materials’ rheological properties. Herein, we develop a new metal 3D printing strategy by utilizing micro-continuous liquid interface printing (μCLIP) to print PMC resins comprising nanoporous copper (NP-Cu) powders. By balancing the need for higher filler loading and the requirements on rheological properties to enable printability for the μCLIP, the compositions of PMC resin were optimized. In detail, the concentration of the NP-Cu powders in the resins can reach up to 40 wt% without sacrificing the printability and printing speed (10 μm·s−1). After sintering, 3D copper structures with microscale features (470 ± 140 μm in diameter) manifesting an average resistivity of 150 kΩ·mm can be realized. In summary, this new strategy potentially benefits the rapid prototyping of metal components with higher resolution at faster speeds.
Applications of 3D printing that range from temporary medical devices to environmentally responsible manufacturing will benefit from printable resins that yield polymers with controllable architecture, material properties, and degradation behavior. Towards this goal, poly(β‐amino ester) (PBAE)‐diacrylate resins are investigated due to the wide range of available chemistries and tunable material properties. PBAE‐diacrylate resins are synthesized from hydrophilic and hydrophobic chemistries and with varying electron densities on the ester bond to provide control over degradation. Hydrophilic PBAE‐diacrylates led to degradation behaviors characteristic of bulk degradation, while hydrophobic PBAE‐diacrylates led to degradation behaviors dominated initially by surface degradation and then transitioned to bulk degradation. Depending on the chemistry, the crosslinked PBAE‐polymers exhibited a range of degradation times under accelerated conditions, from complete mass loss in 90 min to minimal mass loss at 45 days. Patterned features with 55 µm resolution are achieved across all resins, but their fidelity is dependent on PBAE‐diacrylate molecular weight, reactivity, and printing parameters. In summary, simple chemical modifications in the PBAE‐diacrylate resins coupled with projection microstereolithography enable high‐resolution 3D printed parts with similar architectures and initial properties but widely different degradation rates and behaviors.
more » « less- PAR ID:
- 10448399
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Volume:
- 32
- Issue:
- 6
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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