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  • Review Article
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Reprogrammable recovery and actuation behaviour of shape-memory polymers

Abstract

Shape memory is the capability of a material to be deformed and fixed into a temporary shape. Recovery of the original shape can then be triggered only by an external stimulus. Shape-memory polymers are highly deformable materials that can be programmed to recover a memorized shape in response to a variety of environmental and spatially localized stimuli as a one-way effect. The shape-memory function can also be generated as a reversible effect enabling actuation behaviour through macroscale deformation and processing, specifically by dictating the macromolecular orientation of actuation units and of the skeleton structure of geometry-determining units in the polymers. Shape-memory polymers can be programmed and reprogrammed into arbitrary shapes. Both recovery and actuation behaviour are reprogrammable. In this Review, we outline the common basis and key differences between the two shape-memory behaviours of polymers in terms of mechanism, fabrication schemes and characterization methods. We discuss which combination of macromolecular architecture and macroscale processing is necessary for coordinated, decentralized and responsive physical behaviour. The extraction of relevant thermomechanical information is described, and design criteria are shown for microscale and macroscale morphologies to gain high levels of recovered or actuation strains as well as on-demand 2D-to-3D shape transformations. Finally, real-world applications and key future challenges are highlighted.

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Fig. 1: Programming of a coordinated physical response in polymeric systems.
Fig. 2: Thermally controlled subunits for complex physical behaviour.
Fig. 3: Quantification of a one-way shape-memory effect.
Fig. 4: Quantification of a reversible shape-memory effect.
Fig. 5: Morphologies of shape-memory polymers.
Fig. 6: Miniaturization of shape-memory technology.
Fig. 7: Miniaturized shape-memory technology — recovery behaviour and its quantification.
Fig. 8: Real-world applications.

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References

  1. Poppinga, S. et al. Toward a new generation of smart biomimetic actuators for architecture. Adv. Mater. 30, 1703653 (2018).

    Google Scholar 

  2. Poppinga, S. et al. Hygroscopic motions of fossil conifer cones. Sci. Rep. 7, 40302 (2017).

    CAS  Google Scholar 

  3. Swain, M. V. Shape memory behaviour in partially stabilized zirconia ceramics. Nature 324, 148–152 (1986).

    Google Scholar 

  4. Mohd Jani, J., Leary, M., Subic, A. & Gibson, M. A. A review of shape memory alloy research, applications and opportunities. Mater. Des. 56, 1078–1113 (2014).

    CAS  Google Scholar 

  5. Lendlein, A. & Kelch, S. Shape-memory polymers. Angew. Chem., Int. Ed. 41, 2034–2057 (2002).

    CAS  Google Scholar 

  6. Qiu, Y. & Park, K. Environment-sensitive hydrogels for drug delivery. Adv. Drug Deliv. Rev. 64, 49–60 (2012).

    Google Scholar 

  7. Ohm, C., Brehmer, M. & Zentel, R. Liquid crystalline elastomers as actuators and sensors. Adv. Mater. 22, 3366–3387 (2010).

    CAS  Google Scholar 

  8. Löwenberg, C., Balk, M., Wischke, C., Behl, M. & Lendlein, A. Shape-memory hydrogels: evolution of structural principles to enable shape switching of hydrophilic polymer networks. Acc. Chem. Res. 50, 723–732 (2017).

    Google Scholar 

  9. Rousseau, I. A. & Mather, P. T. Shape memory effect exhibited by smectic-C liquid crystalline elastomers. J. Am. Chem. Soc. 125, 15300–15301 (2003).

    CAS  Google Scholar 

  10. Lendlein, A., Jiang, H., Jünger, O. & Langer, R. Light-induced shape-memory polymers. Nature 434, 879 (2005). A one-way shape-memory effect is programmed and directly triggered by light in a polymer network containing side groups capable of undergoing a photoreversible reaction.

    CAS  Google Scholar 

  11. Wagermaier, W., Kratz, K., Heuchel, M. & Lendlein, A. Shape-memory polymers and shape-changing polymers. Adv. Polym. Sci. 226, 97–145 (2010).

    CAS  Google Scholar 

  12. Charlesby, A. Atomic Radiation and Polymers (Pergamon Press, NY, 1960).

  13. Mondal, S. & Hu, J. L. Temperature stimulating shape memory polyurethane for smart clothing. Indian J. Fibre Text. Res. 31, 66–71 (2006).

    CAS  Google Scholar 

  14. Lendlein, A., Behl, M., Hiebl, B. & Wischke, C. Shape-memory polymers as a technology platform for biomedical applications. Expert Rev. Med. Devices 7, 357–379 (2010).

    CAS  Google Scholar 

  15. Liu, Y. et al. Development of a smart, anti-water polyurethane polymer hair coating for style setting. Int. J. Cosmet. Sci. 38, 305–311 (2016).

    Google Scholar 

  16. Huang, W., Yang, B., An, L., Li, C. & Chan, Y. Water-driven programmable polyurethane shape memory polymer: demonstration and mechanism. Appl. Phys. Lett. 86, 114105 (2005).

    Google Scholar 

  17. Yang, B., Huang, W., Li, C., Lee, C. & Li, L. On the effects of moisture in a polyurethane shape memory polymer. Smart Mater. Struct. 13, 191 (2003).

    Google Scholar 

  18. Zhou, S. et al. Hydrogen bonding interaction of poly(D,L-lactide)/hydroxyapatite nanocomposites. Chem. Mater. 19, 247–253 (2007).

    CAS  Google Scholar 

  19. Dong, J. & Weiss, R. A. Shape memory behavior of zinc oleate-filled elastomeric ionomers. Macromolecules 44, 8871–8879 (2011).

    CAS  Google Scholar 

  20. Liu, G., Ding, X., Cao, Y., Zheng, Z. & Peng, Y. Shape memory of hydrogen-bonded polymer network/poly(ethylene glycol) complexes. Macromolecules 37, 2228–2232 (2004).

    CAS  Google Scholar 

  21. Zotzmann, J., Behl, M., Hofmann, D. & Lendlein, A. Reversible triple-shape effect of polymer networks containing polypentadecalactone- and poly(ε-caprolactone)-segments. Adv. Mater. 22, 3424–3429 (2010).

    CAS  Google Scholar 

  22. Behl, M., Kratz, K., Zotzmann, J., Nöchel, U. & Lendlein, A. Reversible bidirectional shape-memory polymers. Adv. Mater. 25, 4466–4469 (2013). The reversible, bidirectional shape-memory effect is realized for polymers by translating reversible effects from the nanoscale to the macroscale, enabling reprogrammable soft actuators.

    CAS  Google Scholar 

  23. Kratz, K., Madbouly, S. A., Wagermaier, W. & Lendlein, A. Temperature-memory polymer networks with crystallizable controlling units. Adv. Mater. 23, 4058–4062 (2011).

    CAS  Google Scholar 

  24. Xie, T. Tunable polymer multi-shape memory effect. Nature 464, 267 (2010). A one-way multi-shape-memory effect is obtained by thermomechanical processing of a commercially available polymer.

    CAS  Google Scholar 

  25. Miaudet, P. et al. Shape and temperature memory of nanocomposites with broadened glass transition. Science 318, 1294–1296 (2007). A one-way temperature-memory effect is enabled for a nanocomposite with a glass transition covering a broad temperature range.

    CAS  Google Scholar 

  26. Bellin, I., Kelch, S. & Lendlein, A. Dual-shape properties of triple-shape polymer networks with crystallizable network segments and grafted side chains. J. Mater. Chem. 17, 2885–2891 (2007).

    CAS  Google Scholar 

  27. Bellin, I., Kelch, S., Langer, R. & Lendlein, A. Polymeric triple-shape materials. Proc. Natl Acad. Sci. USA 103, 18043–18047 (2006).

    CAS  Google Scholar 

  28. Behl, M., Bellin, I., Kelch, S., Wagermaier, W. & Lendlein, A. One-step process for creating triple-shape capability of AB polymer networks. Adv. Funct. Mater. 19, 102–108 (2009).

    CAS  Google Scholar 

  29. Koerner, H., Price, G., Pearce, N. A., Alexander, M. & Vaia, R. A. Remotely actuated polymer nanocomposites — stress-recovery of carbon-nanotube-filled thermoplastic elastomers. Nat. Mater. 3, 115 (2004). Remote actuation of a one-way shape-memory effect is achieved by indirectly heating a composite containing carbon nanotubes with infrared light.

    CAS  Google Scholar 

  30. Mohr, R. et al. Initiation of shape-memory effect by inductive heating of magnetic nanoparticles in thermoplastic polymers. Proc. Natl Acad. Sci. USA 103, 3540–3545 (2006). A one-way shape-memory effect is magnetically triggered for a nanocomposite by sequentially coupling magnetosensitivity and thermosensitivity.

    CAS  Google Scholar 

  31. Zhao, Q., Qi, H. J. & Xie, T. Recent progress in shape memory polymer: new behavior, enabling materials, and mechanistic understanding. Prog. Polym. Sci. 49, 79–120 (2015).

    Google Scholar 

  32. Hu, J., Zhu, Y., Huang, H. & Lu, J. Recent advances in shape–memory polymers: structure, mechanism, functionality, modeling and applications. Prog. Polym. Sci. 37, 1720–1763 (2012).

    CAS  Google Scholar 

  33. Jiang, H., Kelch, S. & Lendlein, A. Polymers move in response to light. Adv. Mater. 18, 1471–1475 (2006).

    CAS  Google Scholar 

  34. Aoki, D., Teramoto, Y. & Nishio, Y. SH-containing cellulose acetate derivatives: preparation and characterization as a shape memory-recovery material. Biomacromolecules 8, 3749–3757 (2007).

    CAS  Google Scholar 

  35. Zheng, N., Fang, Z., Zou, W., Zhao, Q. & Xie, T. Thermoset shape-memory polyurethane with intrinsic plasticity enabled by transcarbamoylation. Angew. Chem. Int. Ed. Engl. 55, 11421–11425 (2016).

    CAS  Google Scholar 

  36. Zhao, Q., Zou, W., Luo, Y. & Xie, T. Shape memory polymer network with thermally distinct elasticity and plasticity. Sci. Adv. 2, e1501297 (2016).

    Google Scholar 

  37. Xie, T. & Rousseau, I. A. Facile tailoring of thermal transition temperatures of epoxy shape memory polymers. Polymer 50, 1852–1856 (2009).

    CAS  Google Scholar 

  38. Yakacki, C. M. et al. Strong, tailored, biocompatible shape-memory polymer networks. Adv. Funct. Mater. 18, 2428–2435 (2008).

    CAS  Google Scholar 

  39. Behl, M., Kratz, K., Noechel, U., Sauter, T. & Lendlein, A. Temperature-memory polymer actuators. Proc. Natl Acad. Sci. USA 110, 12555–12559 (2013).

    CAS  Google Scholar 

  40. Chung, T., Romo-Uribe, A. & Mather, P. T. Two-way reversible shape memory in a semicrystalline network. Macromolecules 41, 184–192 (2008).

    CAS  Google Scholar 

  41. Naue, I. F. & Wilhelm, M. Das Entropierad: maschine aus konformationsänderungen [German]. Phys. Unserer Zeit 44, 36–39 (2013).

    Google Scholar 

  42. Camacho-Lopez, M., Finkelmann, H., Palffy-Muhoray, P. & Shelley, M. Fast liquid-crystal elastomer swims into the dark. Nat. Mater. 3, 307 (2004).

    CAS  Google Scholar 

  43. Palagi, S. et al. Structured light enables biomimetic swimming and versatile locomotion of photoresponsive soft microrobots. Nat. Mater. 15, 647 (2016).

    CAS  Google Scholar 

  44. Liu, Y., Gall, K., Dunn, M. L., Greenberg, A. R. & Diani, J. Thermomechanics of shape memory polymers: uniaxial experiments and constitutive modeling. Int. J. Plast. 22, 279–313 (2006).

    CAS  Google Scholar 

  45. Tobushi, H., Okumura, K., Endo, M. & Hayashi, S. Thermomechanical properties of polyurethane-shape memory polymer foam. J. Intell. Mater. Syst. Struct. 12, 283–287 (2001).

    CAS  Google Scholar 

  46. Liu, Y., Gall, K., Dunn, M. L. & McCluskey, P. Thermomechanical recovery couplings of shape memory polymers in flexure. Smart Mater. Struct. 12, 947 (2003).

    CAS  Google Scholar 

  47. Gall, K. et al. Thermomechanics of the shape memory effect in polymers for biomedical applications. J. Biomed. Mater. Res. A 73, 339–348 (2005).

    Google Scholar 

  48. Fabrizio, Q., Loredana, S. & Anna, S. E. Shape memory epoxy foams for space applications. Mater. Lett. 69, 20–23 (2012).

    CAS  Google Scholar 

  49. Khan, F., Koo, J.-H., Monk, D. & Eisbrenner, E. Characterization of shear deformation and strain recovery behavior in shape memory polymers. Polym. Test. 27, 498–503 (2008).

    CAS  Google Scholar 

  50. Nguyen, T. D. Modeling shape-memory behavior of polymers. Polym. Rev. 53, 130–152 (2013).

    CAS  Google Scholar 

  51. Heuchel, M., Sauter, T., Kratz, K. & Lendlein, A. Thermally induced shape-memory effects in polymers: quantification and related modeling approaches. J. Polym. Sci. B Polym. Phys. 51, 621–637 (2013).

    CAS  Google Scholar 

  52. Li, J., Rodgers, W. R. & Xie, T. Semi-crystalline two-way shape memory elastomer. Polymer 52, 5320–5325 (2011).

    CAS  Google Scholar 

  53. Leng, J., Zhang, D., Liu, Y., Yu, K. & Lan, X. Study on the activation of styrene-based shape memory polymer by medium-infrared laser light. Appl. Phys. Lett. 96, 111905 (2010).

    Google Scholar 

  54. Leng, J., Lan, X., Liu, Y. & Du, S. Electroactive thermoset shape memory polymer nanocomposite filled with nanocarbon powders. Smart Mater. Struct. 18, 074003 (2009).

    Google Scholar 

  55. Suzuki, K., Yamada, H., Miura, H. & Takanobu, H. Self-assembly of three dimensional micro mechanisms using thermal shrinkage of polyimide. Microsyst. Technol. 13, 1047–1053 (2007).

    CAS  Google Scholar 

  56. Leong, T. G. et al. Tetherless thermobiochemically actuated microgrippers. Proc. Natl Acad. Sci. USA 106, 703–708 (2009).

    CAS  Google Scholar 

  57. Hawkes, E. et al. Programmable matter by folding. Proc. Natl Acad. Sci. USA 107, 12441–12445 (2010).

    CAS  Google Scholar 

  58. Yi, Y. W. & Liu, C. Magnetic actuation of hinged microstructures. J. Microelectromech. Syst. 8, 10–17 (1999).

    Google Scholar 

  59. Judy, J. W. & Muller, R. S. Magnetically actuated, addressable microstructures. J. Microelectromech. Syst. 6, 249–256 (1997).

    Google Scholar 

  60. Guan, J., He, H., Hansford, D. J. & Lee, L. J. Self-folding of three-dimensional hydrogel microstructures. J. Phys. Chem. B 109, 23134–23137 (2005).

    CAS  Google Scholar 

  61. Lee, K. M., Koerner, H., Vaia, R. A., Bunning, T. J. & White, T. J. Light-activated shape memory of glassy, azobenzene liquid crystalline polymer networks. Soft Matter 7, 4318–4324 (2011).

    CAS  Google Scholar 

  62. Liu, N., Xie, Q., Huang, W., Phee, S. & Guo, N. Formation of micro protrusion arrays atop shape memory polymer. J. Micromech. Microeng. 18, 027001 (2008).

    Google Scholar 

  63. Jin, B. et al. Programming a crystalline shape memory polymer network with thermo-and photo-reversible bonds toward a single-component soft robot. Sci. Adv. 4, eaao3865 (2018).

    Google Scholar 

  64. Mao, Y. et al. 3D printed reversible shape changing components with stimuli responsive materials. Sci. Rep. 6, 24761 (2016).

    Google Scholar 

  65. Ge, Q., Qi, H. J. & Dunn, M. L. Active materials by four-dimension printing. Appl. Phys. Lett. 103, 131901 (2013).

    Google Scholar 

  66. Ge, Q., Dunn, C. K., Qi, H. J. & Dunn, M. L. Active origami by 4D printing. Smart Mater. Struct. 23, 094007 (2014).

    Google Scholar 

  67. Felton, S., Tolley, M., Demaine, E., Rus, D. & Wood, R. A method for building self-folding machines. Science 345, 644–646 (2014). An elegant demonstration is given for the applicability of the reversible shape-memory effect to origami-based methods.

    CAS  Google Scholar 

  68. Schaedler, T. A. et al. Ultralight metallic microlattices. Science 334, 962–965 (2011).

    CAS  Google Scholar 

  69. Metcalfe, A. et al. Cold hibernated elastic memory foams for endovascular interventions. Biomaterials 24, 491–497 (2003).

    CAS  Google Scholar 

  70. De Nardo, L. et al. Shape memory polymer foams for cerebral aneurysm reparation: effects of plasma sterilization on physical properties and cytocompatibility. Acta Biomater. 5, 1508–1518 (2009).

    Google Scholar 

  71. Sokolowski, W. M. & Tan, S. C. Advanced self-deployable structures for space applications. J. Spacecr. Rockets 44, 750–754 (2007).

    Google Scholar 

  72. Weigel, T., Schinkel, G. & Lendlein, A. Design and preparation of polymeric scaffolds for tissue engineering. Expert Rev. Med. Devices 3, 835–851 (2006).

    CAS  Google Scholar 

  73. Di Prima, M. et al. Deformation of epoxy shape memory polymer foam. Part I: experiments and macroscale constitutive modeling. Mech. Mater. 42, 304–314 (2010).

    Google Scholar 

  74. Sauter, T., Kratz, K. & Lendlein, A. Pore-size distribution controls shape-memory properties on the macro-and microscale of polymeric foams. Macromol. Chem. Phys. 214, 1184–1188 (2013).

    CAS  Google Scholar 

  75. Zharinova, E. et al. Water-blown polyurethane foams showing a reversible shape-memory effect. Polymers 8, 412 (2016).

    Google Scholar 

  76. Mitragotri, S. & Kost, J. Low-frequency sonophoresis: a noninvasive method of drug delivery and diagnostics. Biotechnol. Prog. 16, 488–492 (2000).

    CAS  Google Scholar 

  77. Mitragotri, S., Blankschtein, D. & Langer, R. Ultrasound-mediated transdermal protein delivery. Science 269, 850–853 (1995).

    CAS  Google Scholar 

  78. Mesiwala, A. H. et al. High-intensity focused ultrasound selectively disrupts the blood-brain barrier in vivo. Ultrasound Med. Biol 28, 389–400 (2002).

    Google Scholar 

  79. Zhang, P., Behl, M., Peng, X., Razzaq, M. Y. & Lendlein, A. Ultrasonic cavitation induced shape-memory effect in porous polymer networks. Macromol. Rapid Commun. 37, 1897–1903 (2016).

    CAS  Google Scholar 

  80. Wang, Z. et al. Programmable, pattern-memorizing polymer surface. Adv. Mater. 23, 3669–3673 (2011).

    CAS  Google Scholar 

  81. Reddy, S., Arzt, E. & del Campo, A. Bioinspired surfaces with switchable adhesion. Adv. Mater. 19, 3833–3837 (2007).

    CAS  Google Scholar 

  82. Xie, T. & Xiao, X. Self-peeling reversible dry adhesive system. Chem. Mater. 20, 2866–2868 (2008).

    CAS  Google Scholar 

  83. Kim, S., Sitti, M., Xie, T. & Xiao, X. Reversible dry micro-fibrillar adhesives with thermally controllable adhesion. Soft Matter 5, 3689–3693 (2009).

    CAS  Google Scholar 

  84. Wang, R., Xiao, X. & Xie, T. Viscoelastic behavior and force nature of thermo-reversible epoxy dry adhesives. Macromol. Rapid Commun. 31, 295–299 (2010).

    CAS  Google Scholar 

  85. Eisenhaure, J. D., Xie, T., Varghese, S. & Kim, S. Microstructured shape memory polymer surfaces with reversible dry adhesion. ACS Appl. Mater. Interfaces 5, 7714–7717 (2013).

    CAS  Google Scholar 

  86. Huang, Y. et al. Direct laser writing-based programmable transfer printing via bioinspired shape memory reversible adhesive. ACS Appl. Mater. Interfaces 8, 35628–35633 (2016).

    CAS  Google Scholar 

  87. Chen, C. M. & Yang, S. Directed water shedding on high-aspect-ratio shape memory polymer micropillar arrays. Adv. Mater. 26, 1283–1288 (2014).

    CAS  Google Scholar 

  88. Xu, H. et al. Deformable, programmable, and shape-memorizing micro-optics. Adv. Funct. Mater. 23, 3299–3306 (2013).

    CAS  Google Scholar 

  89. Champion, J. A. & Mitragotri, S. Role of target geometry in phagocytosis. Proc. Natl Acad. Sci. USA 103, 4930–4934 (2006).

    CAS  Google Scholar 

  90. Nelson, B. A., King, W. P. & Gall, K. Shape recovery of nanoscale imprints in a thermoset “shape memory” polymer. Appl. Phys. Lett. 86, 103108 (2005).

    Google Scholar 

  91. Wornyo, E., Gall, K., Yang, F. & King, W. Nanoindentation of shape memory polymer networks. Polymer 48, 3213–3225 (2007).

    CAS  Google Scholar 

  92. Liu, N., Huang, W., Phee, S., Fan, H. & Chew, K. A generic approach for producing various protrusive shapes on different size scales using shape-memory polymer. Smart Mater. Struct. 16, N47 (2007).

    CAS  Google Scholar 

  93. Wischke, C., Schossig, M. & Lendlein, A. Shape-memory effect of micro-/nanoparticles from thermoplastic multiblock copolymers. Small 10, 83–87 (2014).

    CAS  Google Scholar 

  94. Wischke, C. & Lendlein, A. Method for preparation, programming, and characterization of miniaturized particulate shape-memory polymer matrices. Langmuir 30, 2820–2827 (2014).

    CAS  Google Scholar 

  95. Fang, L. et al. Implementing and quantifying the shape-memory effect of single polymeric micro/nanowires with an atomic force microscope. ChemPhysChem 19, 2078 (2018).

    CAS  Google Scholar 

  96. Liu, Y. et al. Two-level shape changes of polymeric microcuboids prepared from crystallizable copolymer networks. Macromolecules 50, 2518–2527 (2017).

    CAS  Google Scholar 

  97. Davis, K. A., Burke, K. A., Mather, P. T. & Henderson, J. H. Dynamic cell behavior on shape memory polymer substrates. Biomaterials 32, 2285–2293 (2011).

    CAS  Google Scholar 

  98. Zhang, Q., Sauter, T., Fang, L., Kratz, K. & Lendlein, A. Shape-memory capability of copolyetheresterurethane microparticles prepared via electrospraying. Macromol. Mater. Eng. 300, 522–530 (2015).

    CAS  Google Scholar 

  99. Fu, C. C. et al. Tunable nanowrinkles on shape memory polymer sheets. Adv. Mater. 21, 4472–4476 (2009).

    CAS  Google Scholar 

  100. Jiang, Y., Fang, L., Kratz, K. & Lendlein, A. Influence of compression direction on the shape-memory effect of micro-cylinder arrays prepared from semi-crystalline polymer networks. MRS Adv. 1, 1985–1993 (2016).

    CAS  Google Scholar 

  101. Cox, L. M. et al. Influences of substrate adhesion and particle size on the shape memory effect of polystyrene particles. Langmuir 32, 3691–3698 (2016).

    CAS  Google Scholar 

  102. Cox, L. M. et al. Light-stimulated permanent shape reconfiguration in cross-linked polymer microparticles. ACS Appl. Mater. Interfaces 9, 14422–14428 (2017).

    CAS  Google Scholar 

  103. Jiang, C., Uto, K., Ebara, M., Aoyagi, T. & Ichiki, T. Implementation of poly (ε-caprolactone) sheet-based shape-memory polymer microvalves into plastic-based microfluidic devices. Jpn. J. Appl. Phys. 54, 06FN02 (2015).

    Google Scholar 

  104. Ebara, M., Uto, K., Idota, N., Hoffman, J. M. & Aoyagi, T. Rewritable and shape-memory soft matter with dynamically tunable microchannel geometry in a biological temperature range. Soft Matter 9, 3074–3080 (2013).

    CAS  Google Scholar 

  105. Steidle, N. E., Schneider, M., Ahrens, R., Worgull, M. & Guber, A. E. in 2013 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) 6659–6662 (IEEE, 2013).

  106. Worgull, M. et al. Hot embossing and thermoforming of biodegradable three-dimensional wood structures. RSC Adv. 3, 20060–20064 (2013).

    CAS  Google Scholar 

  107. Kim, D.-H. et al. Nanoscale cues regulate the structure and function of macroscopic cardiac tissue constructs. Proc. Natl Acad. Sci. USA 107, 565–570 (2010).

    CAS  Google Scholar 

  108. Teixeira, A. I., Abrams, G. A., Bertics, P. J., Murphy, C. J. & Nealey, P. F. Epithelial contact guidance on well-defined micro-and nanostructured substrates. J. Cell Sci. 116, 1881–1892 (2003).

    CAS  Google Scholar 

  109. Turner, S. A., Zhou, J., Sheiko, S. S. & Ashby, V. S. Switchable micropatterned surface topographies mediated by reversible shape memory. ACS Appl. Mater. Interfaces 6, 8017–8021 (2014).

    CAS  Google Scholar 

  110. Ebara, M., Uto, K., Idota, N., Hoffman, J. M. & Aoyagi, T. Shape-memory surface with dynamically tunable nano-geometry activated by body heat. Adv. Mater. 24, 273–278 (2012).

    CAS  Google Scholar 

  111. Uto, K., Aoyagi, T., DeForest, C. A., Hoffman, A. S. & Ebara, M. A. Combinational effect of “bulk” and “surface” shape-memory transitions on the regulation of cell alignment. Adv. Healthc. Mater. 6, 1601439 (2017).

    Google Scholar 

  112. Lendlein, A. & Langer, R. Biodegradable, elastic shape-memory polymers for potential biomedical applications. Science 296, 1673–1676 (2002). A degradable, elastic thermoplastic is designed to exhibit a thermally triggered one-way shape-memory effect with potential medical applications.

    Google Scholar 

  113. Neffe, A. T., Hanh, B. D., Steuer, S. & Lendlein, A. Polymer networks combining controlled drug release, biodegradation, and shape memory capability. Adv. Mater. 21, 3394–3398 (2009).

    CAS  Google Scholar 

  114. Stylios, G. K. & Wan, T. Shape memory training for smart fabrics. Trans. Inst. Meas. Control 29, 321–336 (2007).

    Google Scholar 

  115. Farhan, M. et al. Noncontinuously responding polymeric actuators. ACS Appl. Mater. Interfaces 9, 33559–33564 (2017).

    CAS  Google Scholar 

  116. Huang, L. et al. Ultrafast digital printing toward 4D shape changing materials. Adv. Mater. 29, 1605390 (2017).

    Google Scholar 

  117. Zarek, M. et al. 3D printing of shape memory polymers for flexible electronic devices. Adv. Mater. 28, 4449–4454 (2016). This study demonstrates a fabrication scheme for responsive electronic devices based on one-way shape-memory polymers using 3D printing.

    CAS  Google Scholar 

  118. Ge, Q. et al. Multimaterial 4D printing with tailorable shape memory polymers. Sci. Rep. 6, 31110 (2016).

    Google Scholar 

  119. Larson, C. et al. Highly stretchable electroluminescent skin for optical signaling and tactile sensing. Science 351, 1071–1074 (2016).

    CAS  Google Scholar 

  120. Laschi, C., Mazzolai, B. & Cianchetti, M. Soft robotics: technologies and systems pushing the boundaries of robot abilities. Sci. Robot. 1, eaah3690 (2016).

    Google Scholar 

  121. Mazzolai, B. & Mattoli, V. Robotics: generation soft. Nature 536, 400 (2016).

    CAS  Google Scholar 

  122. Sadeghi, A., Mondini, A. & Mazzolai, B. Toward self-growing soft robots inspired by plant roots and based on additive manufacturing technologies. Soft Robot. 4, 211–223 (2017).

    Google Scholar 

  123. Sadeghi, A., Tonazzini, A., Popova, L. & Mazzolai, B. A novel growing device inspired by plant root soil penetration behaviors. PLOS ONE 9, e90139 (2014).

    Google Scholar 

  124. Fischer, P., Nelson, B. J. & Yang, G.-Z. New materials for next-generation robots. Sci. Robot. 2, eaap9294 (2018).

    Google Scholar 

  125. Lendlein, A. Fabrication of reprogrammable shape-memory polymer actuators for robotics. Sci. Robot. 3, eaat9090 (2018).

    Google Scholar 

  126. Pierce, B. F., Bellin, K., Behl, M. & Lendlein, A. Demonstrating the influence of water on shape-memory polymer networks based on poly[(rac-lactide)-co-glycolide] segments in vitro. Int. J. Artif. Organs 34, 172–179 (2011).

    CAS  Google Scholar 

  127. Behl, M., Zotzmann, J. & Lendlein, A. One-way and reversible dual-shape effect of polymer networks based on polypentadecalactone segments. Int. J. Artif. Organs 34, 231–237 (2011).

    CAS  Google Scholar 

  128. Sauter, T., Heuchel, M., Kratz, K. & Lendlein, A. Quantifying the shape-memory effect of polymers by cyclic thermomechanical tests. Polymer Rev. 53, 6–40 (2013).

    CAS  Google Scholar 

  129. Mazurek-Budzyn´ska, M. et al. Poly(carbonate-urea-urethane) networks exhibiting high-strain shape-memory effect. Polym. Adv. Technol. 28, 1285–1293 (2017).

    Google Scholar 

  130. Sauter, T. et al. Shape-memory properties of polyetherurethane foams prepared by thermally induced phase separation. Adv. Engineer. Mater. 14, 818–824 (2012).

    CAS  Google Scholar 

  131. Friess, F., Nöchel, U., Lendlein, A. & Wischke, C. Polymer micronetworks with shape-memory as future platform to explore shape-dependent biological effects. Adv. Healthc. Mater. 3, 1986–1990 (2014).

    CAS  Google Scholar 

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Acknowledgements

The authors thank K. Schmaelzlin for her help and support with the preparation of the manuscript and W. Yan for technical support, performing the measurements displayed in figure 4e.

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The manuscript was written by A.L. and O.E.C.G. The figures were prepared by A.L. and O.E.C.G.

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Correspondence to Andreas Lendlein.

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Lendlein, A., Gould, O.E.C. Reprogrammable recovery and actuation behaviour of shape-memory polymers. Nat Rev Mater 4, 116–133 (2019). https://doi.org/10.1038/s41578-018-0078-8

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