Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Review Article
  • Published:

Soft actuators for real-world applications

Abstract

Inspired by physically adaptive, agile, reconfigurable and multifunctional soft-bodied animals and human muscles, soft actuators have been developed for a variety of applications, including soft grippers, artificial muscles, wearables, haptic devices and medical devices. However, the complex performance of biological systems cannot yet be fully replicated in synthetic designs. In this Review, we discuss new materials and structural designs for the engineering of soft actuators with physical intelligence and advanced properties, such as adaptability, multimodal locomotion, self-healing and multi-responsiveness. We examine how performance can be improved and multifunctionality implemented by using programmable soft materials, and highlight important real-world applications of soft actuators. Finally, we discuss the challenges and opportunities for next-generation soft actuators, including physical intelligence, adaptability, manufacturing scalability and reproducibility, extended lifetime and end-of-life strategies.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Working principles of tethered soft actuators.
Fig. 2: Working principles of untethered and biohybrid soft actuators.
Fig. 3: State-of-the-art soft actuators with potential industrial applications.
Fig. 4: Soft actuators in biomedical applications.
Fig. 5: Encoding physical intelligence in soft robot bodies.

Similar content being viewed by others

References

  1. Madden, J. D. W. et al. Artificial muscle technology: physical principles and naval prospects. IEEE J. Ocean. Eng. 29, 706–728 (2004).

    Article  Google Scholar 

  2. Mirvakili, S. M. & Hunter, I. W. Artificial muscles: mechanisms, applications, and challenges. Adv. Mater. 30, 1704407 (2018).

    Article  Google Scholar 

  3. Rich, S. I., Wood, R. J. & Majidi, C. Untethered soft robotics. Nat. Electron. 1, 102–112 (2018).

    Article  Google Scholar 

  4. Cianchetti, M., Laschi, C., Menciassi, A. & Dario, P. Biomedical applications of soft robotics. Nat. Rev. Mater. 3, 143–153 (2018).

    Article  Google Scholar 

  5. Shintake, J., Rosset, S., Schubert, B., Floreano, D. & Shea, H. Versatile soft grippers with intrinsic electroadhesion based on multifunctional polymer actuators. Adv. Mater. 28, 231–238 (2016).

    Article  CAS  Google Scholar 

  6. 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).

    Article  Google Scholar 

  7. Acome, E. et al. Hydraulically amplified self-healing electrostatic actuators with muscle-like performance. Science 359, 61–65 (2018).

    Article  CAS  Google Scholar 

  8. Ilievski, F., Mazzeo, A. D., Shepherd, R. F., Chen, X. & Whitesides, G. M. Soft robotics for chemists. Angew. Chem. Int. Ed. 50, 1890–1895 (2011).

    Article  CAS  Google Scholar 

  9. Awad, L. N. et al. A soft robotic exosuit improves walking in patients after stroke. Sci. Transl. Med. 9, eaai9084 (2017).

    Article  Google Scholar 

  10. Sitti, M. Physical intelligence as a new paradigm. Extrem. Mech. Lett. 46, 101340 (2021).

    Article  Google Scholar 

  11. Gorissen, B. et al. Hardware sequencing of inflatable nonlinear actuators for autonomous soft robots. Adv. Mater. 31, 1804598 (2019).

    Article  CAS  Google Scholar 

  12. Vasios, N., Gross, A. J., Soifer, S., Overvelde, J. T. B. & Bertoldi, K. Harnessing viscous flow to simplify the actuation of fluidic soft robots. Soft Robot. 7, 1–9 (2019).

    Google Scholar 

  13. Gorissen, B., Melancon, D., Vasios, N., Torbati, M. & Bertoldi, K. Inflatable soft jumper inspired by shell snapping. Sci. Robot. 5, eabb1967 (2020).

    Article  Google Scholar 

  14. Li, S., Vogt, D. M., Rus, D. & Wood, R. J. Fluid-driven origami-inspired artificial muscles. Proc. Natl Acad. Sci. USA 114, 201713450 (2017).

    Article  Google Scholar 

  15. Siéfert, E., Reyssat, E., Bico, J. & Roman, B. Bio-inspired pneumatic shape-morphing elastomers. Nat. Mater. 18, 24–28 (2019).

    Article  Google Scholar 

  16. Hajiesmaili, E. & Clarke, D. R. Reconfigurable shape-morphing dielectric elastomers using spatially varying electric fields. Nat. Commun. 10, 183 (2019).

    Article  Google Scholar 

  17. Chortos, A., Hajiesmaili, E., Morales, J., Clarke, D. R. & Lewis, J. A. 3D printing of interdigitated dielectric elastomer actuators. Adv. Funct. Mater. 30, 1907375 (2020).

    Article  CAS  Google Scholar 

  18. Pelrine, R., Kornbluh, R., Pei, Q. & Joseph, J. High-speed electrically actuated elastomers with strain greater than 100%. Science 287, 836–839 (2000).

    Article  CAS  Google Scholar 

  19. Duduta, M., Hajiesmaili, E., Zhao, H., Wood, R. J. & Clarke, D. R. Realizing the potential of dielectric elastomer artificial muscles. Proc. Natl Acad. Sci. USA 116, 2476–2481 (2019).

    Article  CAS  Google Scholar 

  20. Davidson, Z. S. et al. Monolithic shape-programmable dielectric liquid crystal elastomer actuators. Sci. Adv. 5, eaay0855 (2019).

    Article  CAS  Google Scholar 

  21. Kellaris, N., Venkata, V. G., Smith, G. M., Mitchell, S. K. & Keplinger, C. Peano-HASEL actuators: muscle-mimetic, electrohydraulic transducers that linearly contract on activation. Sci. Robot. 3, eaar3276 (2018).

    Article  Google Scholar 

  22. Rothemund, P., Kellaris, N., Mitchell, S. K., Acome, E. & Keplinger, C. HASEL artificial muscles for a new generation of lifelike robots — recent progress and future opportunities. Adv. Mater. 33, 2003375 (2020).

    Article  Google Scholar 

  23. Cacucciolo, V. et al. Stretchable pumps for soft machines. Nature 572, 516–519 (2019).

    Article  CAS  Google Scholar 

  24. Seok, S. et al. Meshworm: a peristaltic soft robot with antagonistic nickel titanium coil actuators. IEEE/ASME Trans. Mechatron. 18, 1485–1497 (2013).

    Article  Google Scholar 

  25. Aksoy, B. & Shea, H. Reconfigurable and latchable shape-morphing dielectric elastomers based on local stiffness modulation. Adv. Funct. Mater. 30, 2001597 (2020).

    Article  CAS  Google Scholar 

  26. Lima, M. D. et al. Electrically, chemically, and photonically powered torsional and tensile actuation of hybrid carbon nanotube yarn muscles. Science 338, 928–932 (2012).

    Article  CAS  Google Scholar 

  27. Mu, J. et al. Sheath-run artificial muscles. Science 365, 150–155 (2019).

    Article  CAS  Google Scholar 

  28. Kanik, M. et al. Strain-programmable fiber-based artificial muscle. Science 365, 145–150 (2019).

    Article  CAS  Google Scholar 

  29. Yuan, J. et al. Shape memory nanocomposite fibers for untethered high-energy microengines. Science 365, 155–158 (2019).

    Article  CAS  Google Scholar 

  30. Haines, C. S. et al. Artificial muscles from fishing line and sewing thread. Science 343, 868–872 (2014).

    Article  CAS  Google Scholar 

  31. Kang, B. B., Choi, H., Lee, H. & Cho, K.-J. Exo-Glove Poly II: a polymer-based soft wearable robot for the hand with a tendon-driven actuation system. Soft Robot. 6, 214–227 (2018).

    Article  Google Scholar 

  32. Goswami, D., Liu, S., Pal, A., Silva, L. G. & Martinez, R. V. 3D-architected soft machines with topologically encoded motion. Adv. Funct. Mater. 29, 1808713 (2019).

    Article  Google Scholar 

  33. Schlagenhauf, C. et al. Control of tendon-driven soft foam robot hands. In 2018 IEEE-RAS 18th Intl Conf. on Humanoid Robots (Humanoids) 1–7 (IEEE, 2018).

  34. Mishra, A. K., Del Dottore, E., Sadeghi, A., Mondini, A. & Mazzolai, B. SIMBA: tendon-driven modular continuum arm with soft reconfigurable gripper. Front. Robot. AI 4, 4 (2017).

    Article  Google Scholar 

  35. Kim, Y. & Cha, Y. Soft pneumatic gripper with a tendon-driven soft origami pump. Front. Bioeng. Biotechnol. 8, 461 (2020).

    Article  Google Scholar 

  36. Ren, T. et al. A novel tendon-driven soft actuator with self-pumping property. Soft Robot. 7, 130–139 (2020).

    Article  Google Scholar 

  37. Wehner, M. et al. An integrated design and fabrication strategy for entirely soft, autonomous robots. Nature 536, 451–455 (2016).

    Article  CAS  Google Scholar 

  38. Aubin, C. A. et al. Electrolytic vascular systems for energy-dense robots. Nature 571, 51–57 (2019).

    Article  CAS  Google Scholar 

  39. Li, G. et al. Self-powered soft robot in the Mariana Trench. Nature 591, 66–71 (2021).

    Article  CAS  Google Scholar 

  40. Ji, X. et al. An autonomous untethered fast soft robotic insect driven by low-voltage dielectric elastomer actuators. Sci. Robot. 4, eaaz6451 (2019).

    Article  Google Scholar 

  41. He, Q. & Cai, S. Soft pumps for soft robots. Sci. Robot. 6, eabg6640 (2021).

    Article  Google Scholar 

  42. Hu, W., Lum, G. Z., Mastrangeli, M. & Sitti, M. Small-scale soft-bodied robot with multimodal locomotion. Nature 554, 81–85 (2018).

    Article  Google Scholar 

  43. Lu, H. et al. A bioinspired multilegged soft millirobot that functions in both dry and wet conditions. Nat. Commun. 9, 3944 (2018).

    Article  Google Scholar 

  44. Ren, Z., Hu, W., Dong, X. & Sitti, M. Multi-functional soft-bodied jellyfish-like swimming. Nat. Commun. 10, 2703 (2019).

    Article  Google Scholar 

  45. Dong, X. et al. Bioinspired cilia arrays with programmable nonreciprocal motion and metachronal coordination. Sci. Adv. 6, eabc9323 (2020).

    Article  CAS  Google Scholar 

  46. Lum, G. Z. et al. Shape-programmable magnetic soft matter. Proc. Natl Acad. Sci. USA 113, E6007–E6015 (2016).

    Article  CAS  Google Scholar 

  47. Gu, H. et al. Magnetic cilia carpets with programmable metachronal waves. Nat. Commun. 11, 2637 (2020).

    Article  CAS  Google Scholar 

  48. Huang, H.-W. et al. Adaptive locomotion of artificial microswimmers. Sci. Adv. 5, eaau1532 (2019).

    Article  Google Scholar 

  49. Lee, H. et al. 3D-printed programmable tensegrity for soft robotics. Sci. Robot. 5, eaay9024 (2020).

    Article  Google Scholar 

  50. Cao, L. et al. Ferromagnetic liquid metal putty-like material with transformed shape and reconfigurable polarity. Adv. Mater. 32, 2000827 (2020).

    Article  CAS  Google Scholar 

  51. Kim, Y., Yuk, H., Zhao, R., Chester, S. A. & Zhao, X. Printing ferromagnetic domains for untethered fast-transforming soft materials. Nature 558, 274 (2018).

    Article  CAS  Google Scholar 

  52. Cui, J. et al. Nanomagnetic encoding of shape-morphing micromachines. Nature 575, 164–168 (2019).

    Article  CAS  Google Scholar 

  53. Zhang, J. et al. Voxelated three-dimensional miniature magnetic soft machines via multimaterial heterogeneous assembly. Sci. Robot. 6, eabf0112 (2021).

    Article  Google Scholar 

  54. Alapan, Y., Karacakol, A. C., Guzelhan, S. N., Isik, I. & Sitti, M. Reprogrammable shape morphing of magnetic soft machines. Sci. Adv. 6, eabc6414 (2020).

    Article  CAS  Google Scholar 

  55. Deng, H. et al. Laser reprogramming magnetic anisotropy in soft composites for reconfigurable 3D shaping. Nat. Commun. 11, 6325 (2020).

    Article  CAS  Google Scholar 

  56. Mirvakili, S. M., Sim, D., Hunter, I. W. & Langer, R. Actuation of untethered pneumatic artificial muscles and soft robots using magnetically induced liquid-to-gas phase transitions. Sci. Robot. 5, eaaz4239 (2020).

    Article  Google Scholar 

  57. Sitti, M. & Wiersma, D. S. Pros and cons: magnetic versus optical microrobots. Adv. Mater. 32, 1906766 (2020).

    Article  CAS  Google Scholar 

  58. Liu, Y. et al. Humidity- and photo-induced mechanical actuation of cross-linked liquid crystal polymers. Adv. Mater. 29, 1604792 (2017).

    Article  Google Scholar 

  59. Lu, X. et al. Liquid-crystalline dynamic networks doped with gold nanorods showing enhanced photocontrol of actuation. Adv. Mater. 30, 1706597 (2018).

    Article  Google Scholar 

  60. Lancia, F., Ryabchun, A., Nguindjel, A.-D., Kwangmettatam, S. & Katsonis, N. Mechanical adaptability of artificial muscles from nanoscale molecular action. Nat. Commun. 10, 4819 (2019).

    Article  Google Scholar 

  61. Shahsavan, H. et al. Bioinspired underwater locomotion of light-driven liquid crystal gels. Proc. Natl Acad. Sci. USA 117, 5125–5133 (2020).

    Article  CAS  Google Scholar 

  62. Kuenstler, A. S., Kim, H. & Hayward, R. C. Liquid crystal elastomer waveguide actuators. Adv. Mater. 31, e1901216 (2019).

    Article  Google Scholar 

  63. Yang, H. et al. 3D printed photoresponsive devices based on shape memory composites. Adv. Mater. 29, 1701627 (2017).

    Article  Google Scholar 

  64. Liu, J. A.-C., Gillen, J. H., Mishra, S. R., Evans, B. A. & Tracy, J. B. Photothermally and magnetically controlled reconfiguration of polymer composites for soft robotics. Sci. Adv. 5, eaaw2897 (2019).

    Article  CAS  Google Scholar 

  65. Wang, S. et al. Asymmetric elastoplasticity of stacked graphene assembly actualizes programmable untethered soft robotics. Nat. Commun. 11, 4359 (2020).

    Article  Google Scholar 

  66. Wang, Y. et al. Light-activated shape morphing and light-tracking materials using biopolymer-based programmable photonic nanostructures. Nat. Commun. 12, 1651 (2021).

    Article  Google Scholar 

  67. Cai, G., Ciou, J.-H., Liu, Y., Jiang, Y. & Lee, P. S. Leaf-inspired multiresponsive MXene-based actuator for programmable smart devices. Sci. Adv. 5, eaaw7956 (2019).

    Article  CAS  Google Scholar 

  68. Li, J. et al. Photothermal bimorph actuators with in-built cooler for light mills, frequency switches, and soft robots. Adv. Funct. Mater. 340, 1808995 (2019).

    Article  Google Scholar 

  69. Li, C. et al. Fast and programmable locomotion of hydrogel-metal hybrids under light and magnetic fields. Sci. Robot. 5, eabb9822 (2020).

    Article  Google Scholar 

  70. Li, C. et al. Supramolecular–covalent hybrid polymers for light-activated mechanical actuation. Nat. Mater. 19, 900–909 (2020).

    Article  CAS  Google Scholar 

  71. Wang, W. et al. Direct laser writing of superhydrophobic PDMS elastomers for controllable manipulation via Marangoni effect. Adv. Funct. Mater. 27, 1702946 (2017).

    Article  Google Scholar 

  72. Li, M., Wang, X., Dong, B. & Sitti, M. In-air fast response and high speed jumping and rolling of a light-driven hydrogel actuator. Nat. Commun. 11, 3988 (2020).

    Article  CAS  Google Scholar 

  73. Zhu, Q. L. et al. Light-steered locomotion of muscle-like hydrogel by self-coordinated shape change and friction modulation. Nat. Commun. 11, 5166 (2020).

    Article  CAS  Google Scholar 

  74. Zhao, Y. et al. Soft phototactic swimmer based on self-sustained hydrogel oscillator. Sci. Robot. 4, eaax7112 (2019).

    Article  Google Scholar 

  75. Li, M. et al. Flexible magnetic composites for light-controlled actuation and interfaces. Proc. Natl Acad. Sci USA 115, 8119–8124 (2018).

    Article  CAS  Google Scholar 

  76. Li, M., Kim, T., Guidetti, G., Wang, Y. & Omenetto, F. G. Optomechanically actuated microcilia for locally reconfigurable surfaces. Adv. Mater. 32, 2004147 (2020).

    Article  CAS  Google Scholar 

  77. Aghakhani, A., Yasa, O., Wrede, P. & Sitti, M. Acoustically powered surface-slipping mobile microrobots. Proc. Natl Acad. Sci. USA 117, 3469–3477 (2020).

    Article  CAS  Google Scholar 

  78. Ren, L. et al. 3D steerable, acoustically powered microswimmers for single-particle manipulation. Sci. Adv. 5, eaax3084 (2019).

    Article  CAS  Google Scholar 

  79. Ahmed, D. et al. Artificial swimmers propelled by acoustically activated flagella. Nano Lett. 16, 4968–4974 (2016).

    Article  CAS  Google Scholar 

  80. Kaynak, M., Dirix, P. & Sakar, M. S. Addressable acoustic actuation of 3D printed soft robotic microsystems. Adv. Sci. 7, 2001120 (2020).

    Article  CAS  Google Scholar 

  81. Chen, T., Bilal, O. R., Shea, K. & Daraio, C. Harnessing bistability for directional propulsion of soft, untethered robots. Proc. Natl Acad. Sci. USA 115, 5698–5702 (2018).

    Article  CAS  Google Scholar 

  82. Kotikian, A., Truby, R. L., Boley, J. W., White, T. J. & Lewis, J. A. 3D Printing of liquid crystal elastomeric actuators with spatially programed nematic order. Adv. Mater. 30, 1706164 (2018).

    Article  Google Scholar 

  83. 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).

    Article  Google Scholar 

  84. Kotikian, A. et al. Untethered soft robotic matter with passive control of shape morphing and propulsion. Sci. Robot. 4, eaax7044 (2019).

    Article  Google Scholar 

  85. Wang, Y. et al. Stimuli-responsive composite biopolymer actuators with selective spatial deformation behavior. Proc. Natl Acad. Sci. USA 117, 14602–14608 (2020).

    Article  CAS  Google Scholar 

  86. Shin, B. et al. Hygrobot: a self-locomotive ratcheted actuator powered by environmental humidity. Sci. Robot. 3, eaar2629 (2018).

    Article  Google Scholar 

  87. Sydney Gladman, A., Matsumoto, E. A., Nuzzo, R. G., Mahadevan, L. & Lewis, J. A. Biomimetic 4D printing. Nat. Mater. 15, 413–418 (2016).

    Article  CAS  Google Scholar 

  88. Cao, J. et al. Arbitrarily 3D configurable hygroscopic robots with a covalent-noncovalent interpenetrating network and self-healing ability. Adv. Mater. 31, e1900042 (2019).

    Article  Google Scholar 

  89. Li, H., Go, G., Ko, S. Y., Park, J.-O. & Park, S. Magnetic actuated pH-responsive hydrogel-based soft micro-robot for targeted drug delivery. Smart Mater. Struct. 25, 027001 (2016).

    Article  Google Scholar 

  90. Qin, H., Zhang, T., Li, N., Cong, H.-P. & Yu, S.-H. Anisotropic and self-healing hydrogels with multi-responsive actuating capability. Nat. Commun. 10, 2202 (2019).

    Article  Google Scholar 

  91. Jiang, Y., Korpas, L. M. & Raney, J. R. Bifurcation-based embodied logic and autonomous actuation. Nat. Commun. 10, 1–10 (2019).

    Google Scholar 

  92. Mu, J. et al. Molecular-channel driven actuator with considerations for multiple configurations and color switching. Nat. Commun. 9, 590 (2018).

    Article  Google Scholar 

  93. Bartlett, N. W. et al. A 3D-printed, functionally graded soft robot powered by combustion. Science 349, 161–165 (2015).

    Article  CAS  Google Scholar 

  94. Yang, X., Chang, L. & Pérez-Arancibia, N. O. An 88-milligram insect-scale autonomous crawling robot driven by a catalytic artificial muscle. Sci. Robot. 5, eaba0015 (2020).

    Article  Google Scholar 

  95. Pena-Francesch, A., Giltinan, J. & Sitti, M. Multifunctional and biodegradable self-propelled protein motors. Nat. Commun. 10, 3188 (2019).

    Article  Google Scholar 

  96. Kong, L., Ambrosi, A., Nasir, M. Z. M., Guan, J. & Pumera, M. Self-propelled 3D-printed “aircraft carrier” of light-powered smart micromachines for large-volume nitroaromatic explosives removal. Adv. Funct. Mater. 29, 1903872 (2019).

    Article  Google Scholar 

  97. Cangialosi, A. et al. DNA sequence–directed shape change of photopatterned hydrogels via high-degree swelling. Science 357, 1126–1130 (2017).

    Article  CAS  Google Scholar 

  98. Ricotti, L. et al. Biohybrid actuators for robotics: a review of devices actuated by living cells. Sci. Robot. 2, eaaq0495 (2017).

    Article  Google Scholar 

  99. Alapan, Y. et al. Microrobotics and microorganisms. Annu. Rev. Control. Robot. Auton. Syst. 2, 205–230 (2019).

    Article  Google Scholar 

  100. Park, S.-J. et al. Phototactic guidance of a tissue-engineered soft-robotic ray. Science 353, 158–162 (2016).

    Article  CAS  Google Scholar 

  101. Raman, R. et al. Optogenetic skeletal muscle-powered adaptive biological machines. Proc. Natl Acad. Sci. USA 113, 3497–3502 (2016).

    Article  CAS  Google Scholar 

  102. Aydin, O. et al. Neuromuscular actuation of biohybrid motile bots. Proc. Natl Acad. Sci. USA 116, 19841–19847 (2019).

    Article  CAS  Google Scholar 

  103. Raman, R., Cvetkovic, C. & Bashir, R. A modular approach to the design, fabrication, and characterization of muscle-powered biological machines. Nat. Protoc. 12, 519–533 (2017).

    Article  CAS  Google Scholar 

  104. Morimoto, Y., Onoe, H. & Takeuchi, S. Biohybrid robot powered by an antagonistic pair of skeletal muscle tissues. Sci. Robot. 3, eaat4440 (2018).

    Article  Google Scholar 

  105. Li, Z. et al. Biohybrid valveless pump-bot powered by engineered skeletal muscle. Proc. Natl Acad. Sci. USA 116, 1543–1548 (2019).

    Article  CAS  Google Scholar 

  106. Fu, F., Shang, L., Chen, Z., Yu, Y. & Zhao, Y. Bioinspired living structural color hydrogels. Sci. Robot. 3, eaar8580 (2018).

    Article  Google Scholar 

  107. Xu, B. et al. A remotely controlled transformable soft robot based on engineered cardiac tissue construct. Small 15, e1900006 (2019).

    Article  Google Scholar 

  108. Guix, M. et al. Biohybrid soft robots with self-stimulating skeletons. Sci. Robot. 6, eabe7577 (2021).

    Article  Google Scholar 

  109. Park, B.-W., Zhuang, J., Yasa, O. & Sitti, M. Multifunctional bacteria-driven microswimmers for targeted active drug delivery. ACS Nano 11, 8910–8923 (2017).

    Article  CAS  Google Scholar 

  110. Singh, A. V., Hosseinidoust, Z., Park, B.-W., Yasa, O. & Sitti, M. Microemulsion-based soft bacteria-driven microswimmers for active cargo delivery. ACS Nano 11, 9759–9769 (2017).

    Article  CAS  Google Scholar 

  111. Cao, F., Zhang, C., Choo, H. Y. & Sato, H. Insect–computer hybrid legged robot with user-adjustable speed, step length and walking gait. J. R. Soc. Interface 13, 20160060 (2016).

    Article  Google Scholar 

  112. Magdanz, V. et al. IRONSperm: sperm-templated soft magnetic microrobots. Sci. Adv. 6, eaba5855 (2020).

    Article  CAS  Google Scholar 

  113. Xu, N. W. & Dabiri, J. O. Low-power microelectronics embedded in live jellyfish enhance propulsion. Sci. Adv. 6, eaaz3194 (2020).

    Article  CAS  Google Scholar 

  114. Alapan, Y. et al. Soft erythrocyte-based bacterial microswimmers for cargo delivery. Sci. Robot. 3, eaar4423 (2018).

    Article  Google Scholar 

  115. Wu, M. et al. Photosensitizer-bacteria biohybrids promote photodynamic cancer cell ablation and intracellular protein delivery. Chem. Mater. 31, 7212–7220 (2019).

    Article  CAS  Google Scholar 

  116. Shintake, J., Cacucciolo, V., Floreano, D. & Shea, H. Soft robotic grippers. Adv. Mater. 30, 1707035 (2018).

    Article  Google Scholar 

  117. Zhang, Y.-F. et al. Miniature pneumatic actuators for soft robots by high-resolution multimaterial 3D printing. Adv. Mater. Technol. 4, 1900427 (2019).

    Article  Google Scholar 

  118. Paek, J., Cho, I. & Kim, J. Microrobotic tentacles with spiral bending capability based on shape-engineered elastomeric microtubes. Sci. Rep. 5, 10768 (2015).

    Article  CAS  Google Scholar 

  119. Yap, H. K., Ng, H. Y. & Yeow, C.-H. High-force soft printable pneumatics for soft robotic applications. Soft Robot. 3, 144–158 (2016).

    Article  Google Scholar 

  120. Li, X., Cai, X., Gao, Y. & Serpe, M. J. Reversible bidirectional bending of hydrogel-based bilayer actuators. J. Mater. Chem. B 5, 2804–2812 (2017).

    Article  CAS  Google Scholar 

  121. Taccola, S. et al. Toward a new generation of electrically controllable hygromorphic soft actuators. Adv. Mater. 27, 1668–1675 (2015).

    Article  CAS  Google Scholar 

  122. Leeladhar & Singh, J. P. Photomechanical and chemomechanical actuation behavior of graphene–poly(dimethylsiloxane)/gold bilayer tube for multimode soft grippers and volatile organic compounds detection applications. ACS Appl. Mater. Interfaces 10, 33956–33965 (2018).

    Article  CAS  Google Scholar 

  123. Hubbard, A. M., Mailen, R. W., Zikry, M. A., Dickey, M. D. & Genzer, J. Controllable curvature from planar polymer sheets in response to light. Soft Matter 13, 2299–2308 (2017).

    Article  CAS  Google Scholar 

  124. Diller, E. & Sitti, M. Three-dimensional programmable assembly by untethered magnetic robotic micro-grippers. Adv. Funct. Mater. 24, 4397–4404 (2014).

    Article  CAS  Google Scholar 

  125. Abbott, J. J., Diller, E. & Petruska, A. J. Magnetic methods in robotics. Annu. Rev. Control 3, 57–90 (2020).

    Google Scholar 

  126. Fusco, S. et al. An integrated microrobotic platform for on-demand, targeted therapeutic interventions. Adv. Mater. 26, 952–957 (2014).

    Article  CAS  Google Scholar 

  127. Jin, Q., Yang, Y., Jackson, J. A., Yoon, C. & Gracias, D. H. Untethered single cell grippers for active biopsy. Nano Lett. 20, 5383–5390 (2020).

    Article  CAS  Google Scholar 

  128. Malachowski, K. et al. Stimuli-responsive theragrippers for chemomechanical controlled release. Angew. Chem. Int. Ed. 53, 8045–8049 (2014).

    Article  CAS  Google Scholar 

  129. Breger, J. C. et al. Self-folding thermo-magnetically responsive soft microgrippers. ACS Appl. Mater. Interfaces 7, 3398–3405 (2015).

    Article  CAS  Google Scholar 

  130. Shintake, J., Schubert, B., Rosset, S., Shea, H. & Floreano, D. Variable stiffness actuator for soft robotics using dielectric elastomer and low-melting-point alloy. In 2015 IEEE/RSJ Int. Conf. on Intelligent Robots and Systems (IROS) 1097–1102 (IEEE, 2015).

  131. Amend, J., Cheng, N., Fakhouri, S. & Culley, B. Soft robotics commercialization: jamming grippers from research to product. Soft Robot. 3, 213–222 (2016).

    Article  Google Scholar 

  132. Hawkes, E. W., Christensen, D. L., Kyungwon Han, A., Jiang, H. & Cutkosky, M. R. Grasping without squeezing: shear adhesion gripper with fibrillar thin film. In 2015 IEEE Int. Conf. on Robotics and Automation (ICRA) 2305–2312 (IEEE, 2015).

  133. Song, S., Drotlef, D.-M., Majidi, C. & Sitti, M. Controllable load sharing for soft adhesive interfaces on three-dimensional surfaces. Proc. Natl Acad. Sci. USA 114, E4344–E4353 (2017).

    Article  CAS  Google Scholar 

  134. Wang, L., Ha, K.-H., Rodin, G. J., Liechti, K. M. & Lu, N. Mechanics of crater-enabled soft dry adhesives: a review. Front. Mech. Eng. 6, 98 (2020).

    Article  CAS  Google Scholar 

  135. Josephson, R. K. Contraction dynamics and power output of skeletal muscle. Annu. Rev. Physiol. 55, 527–546 (1993).

    Article  CAS  Google Scholar 

  136. Mirfakhrai, T., Madden, J. D. W. & Baughman, R. H. Polymer artificial muscles. Mater. Today 10, 30–38 (2007).

    Article  CAS  Google Scholar 

  137. Christianson, C., Goldberg, N. N., Deheyn, D. D., Cai, S. & Tolley, M. T. Translucent soft robots driven by frameless fluid electrode dielectric elastomer actuators. Sci. Robot. 3, eaat1893 (2018).

    Article  Google Scholar 

  138. Hines, L., Petersen, K., Lum, G. Z. & Sitti, M. Soft actuators for small-scale robotics. Adv. Mater. 29, 1603483 (2017).

    Article  Google Scholar 

  139. Yirmibesoglu, O. D. & Menguc, Y. Hybrid soft sensor with embedded IMUs to measure motion. In 2016 IEEE Int. Conf. on Automation Science and Engineering (CASE) 798–804 (IEEE, 2016).

  140. Farrow, N., McIntire, L. & Correll, N. Functionalized textiles for interactive soft robotics. In 2017 IEEE Int. Conf. on Robotics and Automation (ICRA) 5525–5531 (IEEE, 2017).

  141. Koivikko, A., Raei, E. S., Mosallaei, M., Mäntysalo, M. & Sariola, V. Screen-printed curvature sensors for soft robots. IEEE Sens. J. 18, 223–230 (2018).

    Article  CAS  Google Scholar 

  142. Meerbeek, I. M. V., Sa, C. M. D. & Shepherd, R. F. Soft optoelectronic sensory foams with proprioception. Sci. Robot. 3, eaau2489 (2018).

    Article  Google Scholar 

  143. Thuruthel, T. G., Abidi, S. H., Cianchetti, M., Laschi, C. & Falotico, E. A bistable soft gripper with mechanically embedded sensing and actuation for fast closed-loop grasping. Preprint at https://arxiv.org/abs/1902.04896 (2019).

  144. Bai, H. et al. Stretchable distributed fiber-optic sensors. Science 370, 848–852 (2020).

    Article  CAS  Google Scholar 

  145. Tapia, J., Knoop, E., Mutnỳ, M., Otaduy, M. A. & Bächer, M. Makesense: automated sensor design for proprioceptive soft robots. Soft Robot. 7, 332–345 (2020).

    Article  Google Scholar 

  146. Truby, R. L. et al. Soft somatosensitive actuators via embedded 3D printing. Adv. Mater. 30, 1706383 (2018).

    Article  Google Scholar 

  147. Zhao, H., O’Brien, K., Li, S. & Shepherd, R. F. Optoelectronically innervated soft prosthetic hand via stretchable optical waveguides. Sci. Robot. 1, eaai7529 (2016).

    Article  Google Scholar 

  148. Justus, K. B. et al. A biosensing soft robot: Autonomous parsing of chemical signals through integrated organic and inorganic interfaces. Sci. Robot. 4, eaax0765 (2019).

    Article  Google Scholar 

  149. Chu, C.-Y. & Patterson, R. M. Soft robotic devices for hand rehabilitation and assistance: a narrative review. J. Neuroeng. Rehabil. 15, 9 (2018).

    Article  Google Scholar 

  150. Kim, D. et al. Eyes are faster than hands: a soft wearable robot learns user intention from the egocentric view. Sci. Robot. 4, eaav2949 (2019).

    Article  Google Scholar 

  151. Dang, W., Vinciguerra, V., Lorenzelli, L. & Dahiya, R. Printable stretchable interconnects. Flex. Print. Electron. 2, 013003 (2017).

    Article  Google Scholar 

  152. Wang, H., Totaro, M. & Beccai, L. Toward perceptive soft robots: progress and challenges. Adv. Sci. 5, 1800541 (2018).

    Article  Google Scholar 

  153. Biswas, S. & Visell, Y. Emerging material technologies for haptics. Adv. Mater. Technol. 4, 1900042 (2019).

    Article  Google Scholar 

  154. Miriyev, A., Stack, K. & Lipson, H. Soft material for soft actuators. Nat. Commun. 8, 596 (2017).

    Article  Google Scholar 

  155. Kanjanapas, S., Nunez, C. M., Williams, S. R., Okamura, A. M. & Luo, M. Design and analysis of pneumatic 2-DoF soft haptic devices for shear display. IEEE Robot. Autom. Lett. 4, 1365–1371 (2019).

    Article  Google Scholar 

  156. Thai, M. T., Hoang, T. T., Phan, P. T., Lovell, N. H. & Nho Do, T. Soft microtubule muscle-driven 3-axis skin-stretch haptic devices. IEEE Access. 8, 157878–157891 (2020).

    Article  Google Scholar 

  157. Leroy, E., Hinchet, R. & Shea, H. Multimode hydraulically amplified electrostatic actuators for wearable haptics. Adv. Mater. 32, 2002564 (2020).

    Article  CAS  Google Scholar 

  158. Phung, H., Nguyen, C. T., Jung, H., Nguyen, T. D. & Choi, H. R. Bidirectional tactile display driven by electrostatic dielectric elastomer actuator. Smart Mater. Struct. 29, 035007 (2020).

    Article  CAS  Google Scholar 

  159. Kim, J. et al. Braille display for portable device using flip-latch structured electromagnetic actuator. IEEE Trans. Haptics 13, 59–65 (2020).

    Article  Google Scholar 

  160. Kim, S.-W. et al. Thermal display glove for interacting with virtual reality. Sci. Rep. 10, 11403 (2020).

    Article  Google Scholar 

  161. Torras, N. et al. Tactile device based on opto-mechanical actuation of liquid crystal elastomers. Sens. Actuators A 208, 104–112 (2014).

    Article  CAS  Google Scholar 

  162. Lipomi, D. J., Dhong, C., Carpenter, C. W., Root, N. B. & Ramachandran, V. S. Organic haptics: intersection of materials chemistry and tactile perception. Adv. Funct. Mater. 30, 1906850 (2020).

    Article  CAS  Google Scholar 

  163. Dhong, C. et al. Role of indentation depth and contact area on human perception of softness for haptic interfaces. Sci. Adv. 5, eaaw8845 (2019).

    Article  Google Scholar 

  164. Skylar-Scott, M. A., Mueller, J., Visser, C. W. & Lewis, J. A. Voxelated soft matter via multimaterial multinozzle 3D printing. Nature 575, 330–335 (2019).

    Article  CAS  Google Scholar 

  165. Zhai, Y. et al. Printing multi-material organic haptic actuators. Adv. Mater. 33, 2002541 (2021).

    Article  CAS  Google Scholar 

  166. Kayser, L. V. & Lipomi, D. J. Stretchable conductive polymers and composites based on PEDOT and PEDOT:PSS. Adv. Mater. 31, 1806133 (2019).

    Article  Google Scholar 

  167. Carpenter, C. W. et al. Electropneumotactile stimulation: multimodal haptic actuators enabled by a stretchable conductive polymer on inflatable pockets. Adv. Mater. Technol. 5, 1901119 (2020).

    Article  CAS  Google Scholar 

  168. Jeon, S. et al. A magnetically controlled soft microrobot steering a guidewire in a three-dimensional phantom vascular network. Soft Robot. 6, 54–68 (2018).

    Article  Google Scholar 

  169. Kim, Y., Parada, G. A., Liu, S. & Zhao, X. Ferromagnetic soft continuum robots. Sci. Robot. 4, eaax7329 (2019).

    Article  Google Scholar 

  170. Pancaldi, L. et al. Flow driven robotic navigation of microengineered endovascular probes. Nat. Commun. 11, 6356 (2020).

    Article  CAS  Google Scholar 

  171. Kashyap, V. et al. Multilayer fabrication of durable catheter-deployable soft robotic sensor arrays for efficient left atrial mapping. Sci. Adv. 6, eabc6800 (2020).

    Article  CAS  Google Scholar 

  172. Han, M. et al. Catheter-integrated soft multilayer electronic arrays for multiplexed sensing and actuation during cardiac surgery. Nat. Biomed. Eng. 4, 997–1009 (2020).

    Article  CAS  Google Scholar 

  173. Son, D., Gilbert, H. & Sitti, M. Magnetically actuated soft capsule endoscope for fine-needle biopsy. Soft Robot. 7, 10–21 (2019).

    Article  Google Scholar 

  174. Payne, C. J. et al. Soft robotic ventricular assist device with septal bracing for therapy of heart failure. Sci. Robot. 2, eaan6736 (2017).

    Article  Google Scholar 

  175. Wang, C. & Park, J. Magnetic micropump embedded in contact lens for on-demand drug delivery. Micro Nano Syst. Lett. 8, 1 (2020).

    Article  Google Scholar 

  176. Cabanach, P. et al. Zwitterionic 3D-printed non-immunogenic stealth microrobots. Adv. Mater. 32, 2003013 (2020).

    Article  CAS  Google Scholar 

  177. Ceylan, H. et al. 3D-printed biodegradable microswimmer for theranostic cargo delivery and release. ACS Nano 13, 3353–3362 (2019).

    Article  CAS  Google Scholar 

  178. Park, J., Kim, J., Pané, S., Nelson, B. J. & Choi, H. Acoustically mediated controlled drug release and targeted therapy with degradable 3D porous magnetic microrobots. Adv. Healthc. Mater. 5, 2001096 (2020).

    Google Scholar 

  179. Yang, X. et al. An agglutinate magnetic spray transforms inanimate objects into millirobots for biomedical applications. Sci. Robot. 5, eabc8191 (2020).

    Article  Google Scholar 

  180. Pal, A., Restrepo, V., Goswami, D. & Martinez, R. V. Exploiting mechanical instabilities in soft robotics: control, sensing, and actuation. Adv. Mater. 33, 2006939 (2021).

    Article  CAS  Google Scholar 

  181. Rothemund, P. et al. A soft, bistable valve for autonomous control of soft actuators. Sci. Robot. 3, eaar7986 (2018).

    Article  Google Scholar 

  182. Preston, D. J. et al. Digital logic for soft devices. Proc. Natl Acad. Sci. USA 116, 7750–7759 (2019).

    Article  CAS  Google Scholar 

  183. Preston, D. J. et al. A soft ring oscillator. Sci. Robot. 4, eaaw5496 (2019).

    Article  Google Scholar 

  184. Pal, A., Goswami, D. & Martinez, R. V. Elastic energy storage enables rapid and programmable actuation in soft machines. Adv. Funct. Mater. 30, 1906603 (2020).

    Article  CAS  Google Scholar 

  185. Tang, Y. et al. Leveraging elastic instabilities for amplified performance: spine-inspired high-speed and high-force soft robots. Sci. Adv. 6, eaaz6912 (2020).

    Article  Google Scholar 

  186. Wang, T., Ren, Z., Hu, W., Li, M. & Sitti, M. Effect of body stiffness distribution on larval fish–like efficient undulatory swimming. Sci. Adv. 7, eabf7364 (2021).

    Article  Google Scholar 

  187. Rafsanjani, A., Zhang, Y., Liu, B., Rubinstein, S. M. & Bertoldi, K. Kirigami skins make a simple soft actuator crawl. Sci. Robot. 3, eaar7555 (2018).

    Article  Google Scholar 

  188. Jin, L., Forte, A. E., Deng, B., Rafsanjani, A. & Bertoldi, K. Kirigami-inspired inflatables with programmable shapes. Adv. Mater. 32, 2001863 (2020).

    Article  CAS  Google Scholar 

  189. Li, S. et al. A vacuum-driven origami “magic-ball” soft gripper. In 2019 Int. Conf. on Robotics and Automation (ICRA) 7401–7408 (IEEE, 2019).

  190. Cafferty, B. J. et al. Fabricating 3D Structures by combining 2D printing and relaxation of strain. Adv. Mater. Technol. 4, 1800299 (2018).

    Article  Google Scholar 

  191. Coyle, S., Majidi, C., LeDuc, P. & Hsia, K. J. Bio-inspired soft robotics: material selection, actuation, and design. Extrem. Mech. Lett. 22, 51–59 (2018).

    Article  Google Scholar 

  192. Laschi, C. et al. Soft robot arm inspired by the octopus. Adv. Robot. 26, 709–727 (2012).

    Article  Google Scholar 

  193. Laschi, C. & Cianchetti, M. Soft robotics: new perspectives for robot bodyware and control. Front. Bioeng. Biotechnol. 2, 1–5 (2014).

    Article  Google Scholar 

  194. Gu, G., Zou, J., Zhao, R., Zhao, X. & Zhu, X. Soft wall-climbing robots. Sci. Robot. 3, eaat2874 (2018).

    Article  Google Scholar 

  195. Hawkes, E. W., Blumenschein, L. H., Greer, J. D. & Okamura, A. M. A soft robot that navigates its environment through growth. Sci. Robot. 2, eaan3028 (2017).

    Article  Google Scholar 

  196. Zhang, J. et al. Liquid crystal elastomer-based magnetic composite films for reconfigurable shape-morphing soft miniature machines. Adv. Mater. 33, 2006191 (2021).

    Article  CAS  Google Scholar 

  197. Zhang, L., Naumov, P., Du, X., Hu, Z. & Wang, J. Vapomechanically responsive motion of microchannel-programmed actuators. Adv. Mater. 29, 1702231 (2017).

    Article  Google Scholar 

  198. Sanchez, V., Walsh, C. J. & Wood, R. J. Textile technology for soft robotic and autonomous garments. Adv. Funct. Mater. 31, 2008278 (2021).

    Article  CAS  Google Scholar 

  199. Baldé, C. P. et al. The Global e-Waste Monitor 2017: Quantities, Flows, and Resources (United Nations Univ., 2017).

  200. Wang, Z., Zhang, B. & Guan, D. Take responsibility for electronic-waste disposal. Nature 536, 23–25 (2016).

    Article  CAS  Google Scholar 

  201. Blaiszik, B. J. et al. Self-healing polymers and composites. Annu. Rev. Mater. Res. 40, 179–211 (2010).

    Article  CAS  Google Scholar 

  202. Markvicka, E. J., Bartlett, M. D., Huang, X. & Majidi, C. An autonomously electrically self-healing liquid metal–elastomer composite for robust soft-matter robotics and electronics. Nat. Mater. 17, 618–624 (2018).

    Article  CAS  Google Scholar 

  203. Wang, S. & Urban, M. W. Self-healing polymers. Nat. Rev. Mater. 5, 562–583 (2020).

    Article  CAS  Google Scholar 

  204. Pena-Francesch, A., Jung, H., Demirel, M. C. & Sitti, M. Biosynthetic self-healing materials for soft machines. Nat. Mater. 19, 1230–1235 (2020).

    Article  CAS  Google Scholar 

  205. Terryn, S., Brancart, J., Lefeber, D., Assche, G. V. & Vanderborght, B. Self-healing soft pneumatic robots. Sci. Robot. 2, eaan4268 (2017).

    Article  Google Scholar 

  206. Yu, K., Xin, A., Du, H., Li, Y. & Wang, Q. Additive manufacturing of self-healing elastomers. npg Asia Mater. 11, 7 (2019).

    Article  CAS  Google Scholar 

  207. Tee, B. C.-K., Wang, C., Allen, R. & Bao, Z. An electrically and mechanically self-healing composite with pressure- and flexion-sensitive properties for electronic skin applications. Nat. Nanotech 7, 825–832 (2012).

    Article  CAS  Google Scholar 

  208. Tan, Y. J. et al. A transparent, self-healing and high-κ dielectric for low-field-emission stretchable optoelectronics. Nat. Mater. 19, 182–188 (2020).

    Article  CAS  Google Scholar 

  209. Tan, Y. J., Susanto, G. J., Anwar Ali, H. P. & Tee, B. C. K. Progress and roadmap for intelligent self-healing materials in autonomous robotics. Adv. Mater. 33, 2002800 (2020).

    Article  Google Scholar 

  210. Yang, H. et al. Graphene oxide-enabled synthesis of metal oxide origamis for soft robotics. ACS Nano 13, 5410–5420 (2019).

    Article  CAS  Google Scholar 

  211. Pena-Francesch, A. et al. Programmable proton conduction in stretchable and self-healing proteins. Chem. Mater. 30, 898–905 (2018).

    Article  CAS  Google Scholar 

  212. Tomko, J. A. et al. Tunable thermal transport and reversible thermal conductivity switching in topologically networked bio-inspired materials. Nat. Nanotech 13, 959–964 (2018).

    Article  CAS  Google Scholar 

  213. Hartmann, F., Baumgartner, M. & Kaltenbrunner, M. Becoming sustainable, the new frontier in soft robotics. Adv. Mater. 33, 2004413 (2020).

    Article  Google Scholar 

  214. Raman, R. et al. Light-degradable hydrogels as dynamic triggers for gastrointestinal applications. Sci. Adv. 6, eaay0065 (2020).

    Article  CAS  Google Scholar 

  215. Bellinger, A. M. et al. Oral, ultra–long-lasting drug delivery: application toward malaria elimination goals. Sci. Transl. Med. 8, 365ra157 (2016).

    Article  Google Scholar 

  216. Feig, V. R., Tran, H. & Bao, Z. Biodegradable polymeric materials in degradable electronic devices. ACS Cent. Sci. 4, 337–348 (2018).

    Article  CAS  Google Scholar 

  217. Walker, S. et al. Using an environmentally benign and degradable elastomer in soft robotics. Int. J. Intell. Robot. Appl. 1, 124–142 (2017).

    Article  Google Scholar 

  218. Baumgartner, M. et al. Resilient yet entirely degradable gelatin-based biogels for soft robots and electronics. Nat. Mater. 19, 1102–1109 (2020).

    Article  CAS  Google Scholar 

  219. Goudu, S. R. et al. Biodegradable untethered magnetic hydrogel milli-grippers. Adv. Funct. Mater. 30, 2004975 (2020).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

This work is funded by the Max Planck Society, the European Research Council (ERC) Advanced Grant SoMMoR project (grant number 834531) and the German Research Foundation (DFG) Soft Material Robotic Systems (SPP 2100) Program (grant number 2197/3-1). M.L., A.P. and A.P.-F. received the Humboldt Postdoctoral Research Fellowship and thank the Alexander von Humboldt Foundation for their financial support.

Author information

Authors and Affiliations

Authors

Contributions

M.L., A.P., A.A. and A.P.-F. contributed equally to this work. M.S. initiated the Review, and all the authors developed its outline. All authors contributed to the writing and editing of the Review.

Corresponding author

Correspondence to Metin Sitti.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information

Nature Reviews Materials thanks David Gracias, Arianna Menciassi and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Li, M., Pal, A., Aghakhani, A. et al. Soft actuators for real-world applications. Nat Rev Mater 7, 235–249 (2022). https://doi.org/10.1038/s41578-021-00389-7

Download citation

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41578-021-00389-7

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing