Modular 4D Printing via Interfacial Welding of Digital Light-Controllable Dynamic Covalent Polymer Networks

Abstract

Advanced multifunctional devices increasingly rely on challenging complex shapes for their functions. 3D printing offers a solution but is often limited by the fabrication speed and/or material diversity. 4D printing based on digitally controlled 2D-to-3D transformation is advantageous in speed, but the accessible shapes are limited and integration of multiple materials is difficult. We report herein a concept that significantly extends the technological scope by combining 4D printing with modular assembly. Specifically, 4D photo-printed structures based on dynamically crosslinked polymers can be assembled in a modular fashion by interfacial bond exchange. Complex 3D objects with tailorable multiple materials can consequently be produced. This allows the fabrication of sophisticated shape-memory devices including a 3D Miura-patterned structure with zero Poisson's ratio and a Kresling-patterned cylindrical structure with superior mechanical stability. Our approach extends the possibilities for the future development of multifunctional devices with seamless integration of material, structure, and function.

Scalable upcycling of thermoplastic polyolefins into vitrimers through transesterification

“…The presented results provide a foundation to achieve high valued plastic from litter on industrial scale. Concurrence progress in 3D-printing [44][45][46] with these class of polymers endowing mechanical responsiveness to thermal stimulus, recyclability promises next-generation materials in new technological areas.…”

Interfacial Reaction Induced Disruption and Dissolution of Dynamic Polymer Networks

“…Key to these applications (for example, modular 4D printing via interfacial welding of DPNs [ 31,32 ] ) is the intermixing and interpenetration of the materials into the network. For two linear polymers, the segmental interactions between the polymers and the molecular weight and rigidity of the two polymers dictate the extent of interfacial broadening as a function of time, which has been well‐studied and correlated with the change in adhesion.…”

Precise Macroscopic Supramolecular Assemblies: Strategies and Applications

“…Severalcharacteristics of MSA have paved the way for its applications in diverse fields:( 1) the basic idea of modulara ssembly [46,48,86,88,89] in MSA allows for the flexible combination of various building blocks with diverse geometry,s urface chemistry, spatiala lignment, etc.,a nd thusi sf avorable for the fabrication of 3D ordered structures, which hold promise to be used in tissue scaffolds, [21,48,90] soft devices, [29][30][31] etc. ;( 2) the molecular interactions at al arge length scale have as imilar interactive nature with many interfacial phenomena sucha sw et adhesion, [38] self-healing, [37] bio-adhesion, [36] and so forth.…”

“…Moreover,w eh ave furtherr eviewed the currenta pplications of precise MSA in fabricating tissue scaffolds owing to its flexible and mild control over 3D structures, and envisioned proof-of-concept potentialu ses in the fields of additive manufacture, soft devices, and programmable materials. [45,46] Brief History and Development of MSA For al ong time, the industrial manufacture of microsystems, for example, micro-electromechanical systems, has expected a breakthrough from2 Dp rocesses to 3D manufacture, which requires assembly of components. [15] However,t here is increased difficultya nd cost in miniaturizing pick-and-place assembly of micro parts, especially when scaling effects of surface-related forces (electrostatic, van derW aals, surfacet ension,e tc.)…”

“…To be specific, two main kinds of strategies are introduced: (1) control over assembly kinetics by integrating multiple designs of self‐propulsion, self‐alignment, and interfacial molecular interactions; (2) designs based on the thermodynamic difference between imprecise/precise structures and selective assembly of precise assemblies. Moreover, we have further reviewed the current applications of precise MSA in fabricating tissue scaffolds owing to its flexible and mild control over 3D structures, and envisioned proof‐of‐concept potential uses in the fields of additive manufacture, soft devices, and programmable materials [45, 46] …”