Abstract
Semiconducting polymer thin films are essential elements of soft electronics for both wearable and biomedical applications1,2,3,4,5,6,7,8,9,10,11. However, high-mobility semiconducting polymers are usually brittle and can be easily fractured under small strains (<10%)12,13,14. Recently, the improved intrinsic mechanical properties of semiconducting polymer films have been reported through molecular design15,16,17,18 and nanoconfinement19. Here we show that engineering the interfacial properties between a semiconducting thin film and a substrate can notably delay microcrack formation in the film. We present a universal design strategy that involves covalently bonding a dissipative interfacial polymer layer, consisting of dynamic non-covalent crosslinks, between a semiconducting thin film and a substrate. This enables high interfacial toughness between the layers, suppression of delamination and delocalization of strain. As a result, crack initiation and propagation are notably delayed to much higher strains. Specifically, the crack-onset strain of a high-mobility semiconducting polymer thin film improved from 30% to 110% strain without any noticeable microcracks. Despite the presence of a large mismatch in strain between the plastic semiconducting thin film and elastic substrate after unloading, the tough interface layer helped maintain bonding and exceptional cyclic durability and robustness. Furthermore, we found that our interfacial layer reduces the mismatch of thermal expansion coefficients between the different layers. This approach can improve the crack-onset strain of various semiconducting polymers, conducting polymers and even metal thin films.
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The main data supporting the findings of this study are available within the Article and its Supplementary Information. Source data are provided with this paper.
References
Someya, T., Bao, Z. & Malliaras, G. G. The rise of plastic bioelectronics. Nature 540, 379–385 (2016).
Miyamoto, A. et al. Inflammation-free, gas-permeable, lightweight, stretchable on-skin electronics with nanomeshes. Nat. Nanotechnol. 12, 907–913 (2017).
Kang, J., Tok, J. B. H. & Bao, Z. Self-healing soft electronics. Nat. Electron. 2, 144–150 (2019).
Park, S. et al. Self-powered ultra-flexible electronics via nano-grating-patterned organic photovoltaics. Nature 561, 516–521 (2018).
Kaltenbrunner, M. et al. An ultra-lightweight design for imperceptible plastic electronics. Nature 499, 458–463 (2013).
Wagner, S. & Bauer, S. Materials for stretchable electronics. MRS Bull. 37, 207–213 (2012).
Chortos, A., Liu, J. & Bao, Z. Pursuing prosthetic electronic skin. Nat. Mater. 15, 937–950 (2016).
Lee, S. et al. Ultrasoft electronics to monitor dynamically pulsing cardiomyocytes. Nat. Nanotechnol 14, 156–160 (2018).
Wang, S., Oh, J. Y., Xu, J., Tran, H. & Bao, Z. Skin-inspired electronics: an emerging paradigm. Acc. Chem. Res. 51, 1033–1045 (2018).
Wang, S. et al. Skin electronics from scalable fabrication of an intrinsically stretchable transistor array. Nature 555, 83–88 (2018).
Yang, J. C. et al. Electronic skin: recent progress and future prospects for skin‐attachable devices for health monitoring, robotics, and prosthetics. Adv. Mater. 31, 1904765 (2019).
Kim, D.-H. et al. Stretchable and foldable silicon integrated circuits. Science 320, 507–511 (2008).
Kim, D.-H. et al. Epidermal electronics. Science 333, 838–843 (2011).
Root, S. E., Savagatrup, S., Printz, A. D., Rodriquez, D. & Lipomi, D. J. Mechanical properties of organic semiconductors for stretchable, highly flexible, and mechanically robust electronics. Chem. Rev. 117, 6467–6499 (2017).
Oh, J. Y. et al. Intrinsically stretchable and healable semiconducting polymer for organic transistors. Nature 539, 411–415 (2016).
Mun, J. et al. Effect of nonconjugated spacers on mechanical properties of semiconducting polymers for stretchable transistors. Adv. Funct. Mater. 28, 1804222 (2018).
Zheng, Y. et al. An intrinsically stretchable high‐performance polymer semiconductor with low crystallinity. Adv. Funct. Mater. 29, 1905340 (2019).
Zheng, Y., Zhang, S., Tok, J. B. H. & Bao, Z. Molecular design of stretchable polymer semiconductors: current progress and future directions. J. Am. Chem. Soc. 144, 4699–4715 (2022).
Xu, J. et al. Highly stretchable polymer semiconductor films through the nanoconfinement effect. Science 355, 59–64 (2017).
Suo, Z., Vlassak, J. & Wagner, S. Micromechanics of macroelectronics. China Particuol. 3, 321–328 (2005).
Xiang, Y., Li, T., Suo, Z. & Vlassak, J. J. High ductility of a metal film adherent on a polymer substrate. Appl. Phys. Lett. 87, 161910 (2005).
Lu, N., Wang, X., Suo, Z. & Vlassak, J. Metal films on polymer substrates stretched beyond 50%. Appl. Phys. Lett. 91, 221909 (2007).
Lee, S.-Y. et al. Selective crack suppression during deformation in metal films on polymer substrates using electron beam irradiation. Nat. Commun. 10, 4454 (2019).
Yang, J., Bai, R. & Suo, Z. Topological adhesion of wet materials. Adv. Mater. 30, 1800671 (2018).
Liu, Q., Nian, G., Yang, C., Qu, S. & Suo, Z. Bonding dissimilar polymer networks in various manufacturing processes. Nat. Commun. 9, 846 (2018).
Yuk, H., Zhang, T., Lin, S., Parada, G. A. & Zhao, X. Tough bonding of hydrogels to diverse non-porous surfaces. Nat. Mater. 15, 190–196 (2016).
Yuk, H., Zhang, T., Parada, G. A., Liu, X. & Zhao, X. Skin-inspired hydrogel–elastomer hybrids with robust interfaces and functional microstructures. Nat. Commun. 7, 12028 (2016).
Wang, G. N. et al. Tuning the cross-linker crystallinity of a stretchable polymer semiconductor. Chem. Mater. 31, 6465–6475 (2019).
Lee, H., Lee, B. P. & Messersmith, P. B. A reversible wet/dry adhesive inspired by mussels and geckos. Nature 448, 338–341 (2007).
Kang, J. et al. Tough and water-insensitive self-healing elastomer for robust electronic skin. Adv. Mater. 30, 1706846 (2018).
Sun, J. Y. et al. Inorganic islands on a highly stretchable polyimide substrate. J. Mater. Res. 24, 3338–3342 (2009).
Zhang, S. et al. Directly probing the fracture behavior of ultrathin polymeric films. ACS Polym. Au 1, 16–29 (2021).
Wang, Y. et al. A highly stretchable, transparent, and conductive polymer. Sci. Adv. 3, e1602076 (2017).
Ambrico, J. M. & Begley, M. R. The role of initial flaw size, elastic compliance and plasticity in channel cracking of thin films. Thin Solid Films 419, 144–153 (2002).
Beuth, J. L. & Klingbeil, N. W. Cracking of thin films bonded to elastic plastic substrates. J. Mech. Phys. Solids 44, 1411–1428 (1996).
Acknowledgements
This work is supported by Samsung Electronics. J.K. acknowledges support from the National Research Foundation of Korea through grant nos. 2021R1C1C1011116 and 2021M3H4A1A03048658. J.M. acknowledges financial support from Samsung Scholarship. L.J. acknowledges support from the National Science Foundation through grant no. CMMI-1925790. We acknowledge J. Hutchinson of Harvard University for the insightful discussions. Part of this work was performed at the Stanford Nano Shared Facilities (SNSF).
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J.K., J.M. and Z.B. conceived the concept and designed the experiments. J.K. synthesized and characterized the molecules and polymers. Y.Z. provided the conjugated polymers. J.K., J.M., N.M., Y.Z. and G.H.L. designed the device experiments and evaluated the stretchability of materials and devices. J.K. and J.M. fabricated the fully stretchable organic thin-film transistors. M.K. and L.J. performed the mechanical simulations. J.M. and H.-C.W. performed the grazing incidence X-ray diffraction experiments and analysis. S.C. performed the X-ray photoelectron spectroscopy measurements. J.K., J.M., M.K., J.B.-H.T., L.J. and Z.B. wrote the paper.
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Supplementary Figs. 1–26 and Tables 1 and 2.
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Kang, J., Mun, J., Zheng, Y. et al. Tough-interface-enabled stretchable electronics using non-stretchable polymer semiconductors and conductors. Nat. Nanotechnol. 17, 1265–1271 (2022). https://doi.org/10.1038/s41565-022-01246-6
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DOI: https://doi.org/10.1038/s41565-022-01246-6
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