Shape morphing materials have been extensively studied to control the formation of sophisticated three-dimensional (3D) structures and devices for a broad range of applications. Various methods, including the buckling of pre-strained bilayer composites, stimuli-responsive shape-shifting of shape memory polymers, and hydrogels, have been previously employed to transform 2D sheets to 3D structures and devices. However, the residual stress locked in these shape-shifting structures will drive them to gradually revert to their original layouts upon the removal of external stimuli or constrains. Here, we report a multistimuli-responsive vitrimer (m-vitrimer) bearing thermal- and photo-reversible disulfide bonds as shape programmable and healable materials for functional 3D devices. The mechanical properties and thermomechanical properties of vitrimer were tuned by altering the disulfide content and catalyst loading. Heat and light exposure induces effective stress relaxation and network rearrangement, enabling material shape programming and healing. We demonstrate that printed flexible smart electronics are fabricated using the m-vitrimer as a matrix and printed conductive silver nanoparticles as conductive wire. The printed electronics possess good electro-mechanical properties, strong interfacial bonding, and thermal- and photo-responsive shape programming. Moreover, the m-vitrimer can be healed upon damage by heat and light, which partially restores silver conductivity and protect the electronics from further damage. The converging of multi-stimuli-responsive polymers and printed electronics for functional 3D devices have the potential of finding broad applications in smart and morphing electronics, biomedical devices, and 4D printing.
This content will become publicly available on December 4, 2024
Herein, a new lightweight syntactic foam is reported with strong mechanical properties, unique multifunctionalities, and recyclability. Multifunctionality of materials and structures has gained ever‐increasing interest as an excellent approach to designing minimalistic systems. Inspired by nature, these materials can perform multiple functions besides bearing a load. Due to their shape‐changing and damage‐healing property, shape memory vitrimers (SMVs) are a great example of multifunctional materials readily exploited for many applications. Using nickel and silver‐plated hollow glass microbubbles (HGMs), an SMV‐based syntactic foam is introduced here that supplements the multifunctionality of SMVs with electrical conductivity and ferromagnetism, which enables a series of additional potentials such as strain sensing, damage monitoring, Joule heating, and electromagnetic interference shielding. Despite its low density and outstanding mechanical properties, this foam exhibits shape memory behavior, which can be triggered by an electrical current, and damage healing capability due to its reversible dynamic covalent bonds. Especially its recyclability makes recycling the expensive silver‐coated and nickel‐coated HGMs feasible, making this foam cost‐effective and environmentally sustainable. With its many features and economical manufacturability, this syntactic foam has a potential to be utilized in many applications, ranging from aerospace structures to biomedical devices to household items.
more » « less- Award ID(s):
- 1946231
- NSF-PAR ID:
- 10478684
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Functional Materials
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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