Abstract 4D printing is an emerging field where 3D printing techniques are used to pattern stimuli‐responsive materials to create morphing structures, with time serving as the fourth dimension. However, current materials utilized for 4D printing are typically soft, exhibiting an elastic modulus (E) range of 10−4to 10 MPa during shape change. This restricts the scalability, actuation stress, and load‐bearing capabilities of the resulting structures. To overcome these limitations, multiscale heterogeneous polymer composites are introduced as a novel category of stiff, thermally responsive 4D printed materials. These inks exhibit anEthat is four orders of magnitude greater than that of existing 4D printed materials and offer tunable electrical conductivities for simultaneous Joule heating actuation and self‐sensing capabilities. Utilizing electrically controllable bilayers as building blocks, a flat geometry is designed and printed that morphs into a 3D self‐standing lifting robot, setting new records for weight‐normalized load lifted and actuation stress when compared to other 3D printed actuators. Furthermore, the ink palette is employed to create and print planar lattice structures that transform into various self‐supporting complex 3D shapes. These contributions are integrated into a 4D printed electrically controlled multigait crawling robotic lattice structure that can carry 144 times its own weight.
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Nanomaterials in 4D Printing: Expanding the Frontiers of Advanced Manufacturing
As an innovative technology, four‐dimentional (4D) printing is built upon the principles of three‐dimentional (3D) printing with an additional dimension: time. While traditional 3D printing creates static objects, 4D printing generates “responsive 3D printed structures”, enabling them to transform or self‐assemble in response to external stimuli. Due to the dynamic nature, 4D printing has demonstrated tremendous potential in a range of industries, encompassing aerospace, healthcare, and intelligent devices. Nanotechnology has gained considerable attention owing to the exceptional properties and functions of nanomaterials. Incorporating nanomaterials into an intelligent matrix enhances the physiochemical properties of 4D printed constructs, introducing novel functions. This review provides a comprehensive overview of current applications of nanomaterials in 4D printing, exploring their synergistic potential to create dynamic and responsive structures. Nanomaterials play diverse roles as rheology modifiers, mechanical enhancers, function introducers, and more. The overarching goal of this review is to inspire researchers to delve into the vast potential of nanomaterial‐enabled 4D printing, propelling advancements in this rapidly evolving field.
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- PAR ID:
- 10543015
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Small
- Volume:
- 20
- Issue:
- 30
- ISSN:
- 1613-6810
- Page Range / eLocation ID:
- 2307750
- Subject(s) / Keyword(s):
- 4D Printing nanocomposites nanomaterials shape memory materials.
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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