Microfluidic-Directed Hydrogel Fabrics Based on Interfibrillar Self-Healing Effects

Abstract

Multistructural and versatile fibers have attracted enormous interests in various potential applications ranging from tissue engineering and cells to sensors. However, the controllable fabrication and nonwoven assembly of fibers remain a challenge. Here, we developed a novel strategy to in situ fabricate supramolecular hydrogel fibers via microfluidic spinning technology where self-healing fibers can be nonwoven assembled into fabrics through noncovalent interactions (host− guest interactions). We utilized β-cyclodextrin as the host molecule and N-vinylimidazole as the guest molecule to achieve self-healing supramolecular hydrogel fibers. Through design of different microreactors, the beaded, cylindrical, and knotted structure in fibers were achieved. Additionally, we constructed multidimensional (2D plane, 3D bulk, and 3D spiral textile) materials by using self-healing fibers as building blocks. In virtue of the host−guest assembly, the as-fabricated fabric exhibits high flexibility with high strength and long-term stretching behavior. From a practical standpoint, we employed the hydrogel fibers to construct a self-healing conductive composite wire and a planeshaped supercapacitor, which could power light-emitting diodes. Our main aim is to clarify the paramount role of designing various fabrics through noncovalent interactions based on the interfibrillar self-healing feature, which gives a new insight into the facile fabrication of fabrics as well as the next-generation wearable textiles.

Redox‐Active Iron‐Citrate Complex Regulated Robust Coating‐Free Hydrogel Microfiber Net with High Environmental Tolerance and Sensitivity

“…The final hydrogel microfiber net is well aligned, uniform and elastic, and can sustain a certain weight of load like a fishing net (Figure 1b). In principle, any woven 2D or 3D organized patterns with tunable fiber densities can be obtained with this method 19,27. As an example, three fiber nets with different fiber densities were obtained by changing the parallel movement speed of rotating collector (Figure S1, Supporting Information).…”

“…To circumvent this issue, recently Ma et al reported a core–shell stretchable and conductive sodium polyacrylate hydrogel microfiber with a thin elastomer coating layer to prevent dehydration while maintaining good fiber elasticity 14. Nonetheless, the inert elastomer coating evitably leads hydrogel microfiber to be insensitive to environmental changes, which are unfavorable for sensing applications. Spinnability versus fiber strength: compared to electrospinning15,16 and extrusion spinning,9,10,17,18 microfluidic or draw‐spinning inspired from spider spinning procedure11–14,19,20 seems to be more suitable for fabricating long and uniform hydrogel microfibers. However, unless using the strategy of full dehydration, it is still challenging to compromise the spinnability and mechanical strength of hydrogel microfibers.…”

“…Spinnability versus fiber strength: compared to electrospinning15,16 and extrusion spinning,9,10,17,18 microfluidic or draw‐spinning inspired from spider spinning procedure11–14,19,20 seems to be more suitable for fabricating long and uniform hydrogel microfibers. However, unless using the strategy of full dehydration, it is still challenging to compromise the spinnability and mechanical strength of hydrogel microfibers.…”

Advances in Synthesis and Applications of Self-Healing Hydrogels

“…Common molecules used to form host-guest interaction include crown ethers (Xue et al, 2015), calixarenes (Yan et al, 2012), cucurbiturils (Appel et al, 2012), pillararenes (Ogoshi et al, 2016), and cyclodextrins (CDs) (Deng Z. et al, 2018;Li Q. et al, 2018;Wang et al, 2019e;Wu et al, 2008). The authors (Li Q. et al, 2018) used β-cyclodextrin and N-vinylimidazole to achieve hydrogel fibers. The self-healing experiment showed that the cut hydrogel fibers could adhere together within 24 h, and the healed fiber could withstand a reversible stretch.…”

“…Dynamic covalent bonds include imine bond ( Qu et al, 2017 ; Yan et al, 2017 ; Chen H. et al, 2018 ; Chen et al, 2019e ; Khan et al, 2018 ; Wei and Gerecht, 2018 ; Zhang et al, 2018 ; Guo B. et al, 2019 ; Jiang F. et al, 2019 ; Li Q. et al, 2019 ; Qian et al, 2019 ; Wang et al, 2019b ; Wang W. et al, 2019 ; Zhou et al, 2019 ), Diels–Alder (DA) reaction ( Oehlenschlaeger et al, 2014 ), boronate-diol complexation ( Hong et al, 2018 ; Pan et al, 2018 ; Smithmyer et al, 2018 ; Zhi et al, 2018 ; Han et al, 2019 ), acylhydrazone bond ( Yang et al, 2017 ; Shen et al, 2019 ; Sun C. et al, 2019 ), dynamic disulfide bond ( Song L. et al, 2019 ), and dynamic metal oordination ( Shao et al, 2018 ; Chen et al, 2019a ; Qin et al, 2019 ). Physical non-covalent interactions include hydrogen bonding ( Fan et al, 2018 ; Uzumcu et al, 2018 ; Cao et al, 2019 ; Chen et al, 2019c ; Hu et al, 2019 ; Huang et al, 2019 ; Kuddushi et al, 2019 ; Li R. et al, 2019 ; Liao et al, 2019 ; Su et al, 2019 ; Wang L. et al, 2019 ), hydrophobic interaction ( Liu P. et al, 2019 ), host-guest interaction ( Deng Z. et al, 2018 ; Li Q. et al, 2018 ; Liu L. et al, 2019 ; Wang W. et al, 2019 ), and ionic interaction ( Ma et al, 2018 ; Wang Y. et al, 2018 ; Becher et al, 2019 ). Some intrinsic type self-healing hydrogels even have several kinds of networks, containing either one type or several types of mechanisms.…”