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Creating 3D printed structures from materials with shape memory properties allows these structures to change form, modifying configuration or function over time in response to external stimuli such as temperature, light, electrical current, etc. This area of additive manufacturing has come to be known as 4D printing. A variety of geometries have been previously explored in the context of 4D printing, including foldable surfaces (e.g. Origami), lattices, and bio-inspired shapes. However, with advances in solid modeling software tools, more sophisticated spatially- varying lattices are now easily generated to further optimize the mechanical performance and functionality of a 4D printed structure. In this work, complex lattices are created to bend at specific locations with intentionally-reduced stiffness and improved compliance based on locally-reduced strut dimensions. By experimentally demonstrating more complex geometries in the study of 4D printing, new applications can be considered that were not previously possible, with tailored performance allowing for balancing between weight and actuation.
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An exploration of 3D printed freeform kerf structures
This study presents the use of a 3D printing method to create kerf structures that can be formed into complex geometries. Kerfing is a subtractive manufacturing method to create flexible surfaces out of stiff planar materials such as metal or wood sheets by removing portions of the materials. The kerf structures are characterized by the kerf pattern, such as square interlocked Archimedean spiral and hexagon spiral domain, cell size, and cut density. By controlling the kerf pattern, spatial density, cell size, and material, the local properties of the structure can be controlled and optimized to achieve the desired local flexibility while minimizing the stresses developed in the kerf structure. Since subtractive manufacturing limits the patterns and materials that can be considered in kerf structures, FDM 3D printing is explored to fabricate kerf structures using polymers, such as Polylactic acid (PLA) and Thermoplastic polyurethane (TPU), where it is possible to vary microstructural topology and materials within the kerf structures. 3D printing enables the combination of the two different polymers and tuning printing factors to create multifunctional kerf structures. The multifunctional kerf structures can then be actuated using non-mechanical stimulations, such as thermal, to shape them into complex geometries.
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- Award ID(s):
- 2222935
- PAR ID:
- 10438996
- Editor(s):
- Wissa, Aimy; Gutierrez Soto, Mariantonieta; Mailen, Russell W.
- Date Published:
- Journal Name:
- PROCEEDINGS OF SPIE
- Volume:
- 12484
- Page Range / eLocation ID:
- 12
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1117/12.2658554
