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:

Life-like motion driven by artificial molecular machines

Abstract

Essentially, all motion in living organisms emerges from the collective action of biological molecular machines transforming chemical energy, originally harvested from light, into ordered activity. As a man-made counterpart to nature’s biomolecular machines, chemists have created artificial molecular machines that display controlled and even directional motion in response to light. However, to be of practical value, the motion of these light-fuelled molecular machines will have to be coupled to the rest of the world. Inspired by the complex functional movement seen in the plant and animal world, chemists have undertaken the challenge to harness molecular motion and, so, they have set artificial molecular motors and switches to work and perform useful mechanical action at the macroscopic level. Here, we review these recent developments. We show how modern research has embraced the full complexity of the molecular world by aiming at the design of autonomous, and sometimes adaptive, molecular systems that work continuously under the effect of illumination. We report evidence that molecular motion can be engineered into highly sophisticated movements and that, from a fundamental point of view, continuous movement can only emerge when man-made molecules cooperate, in space and time. Eventually, unravelling the rules of molecular motion will support the creation of molecular materials that produce work continuously under a constant input of energy.

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

Access options

Buy this article

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

Fig. 1: Roadmap for the transduction and amplification of molecular motion across increasing length scales.
Fig. 2: Light-induced strain in single-crystal systems.
Fig. 3: Versatility of shapes and actuation modes in mechanized, liquid-crystal networks.
Fig. 4: Motion of self-assembled materials from molecular motors.
Fig. 5: Harnessing molecular motion to drive macroscopic motility.
Fig. 6: Harnessing the continuous rotary motion of molecular motors in mechanized gels.
Fig. 7: Light-induced motion in anisotropic molecular materials.

Similar content being viewed by others

References

  1. Herzog, W. Skeletal Muscle Mechanics: From Mechanisms to Function. (Wiley, Chichester, UK, 2000).

  2. Jarrell, K. F. & McBride, M. J. The surprisingly diverse ways that prokaryotes move. Nat. Rev. Microbiol. 6, 466–476 (2008).

    Article  CAS  PubMed  Google Scholar 

  3. Teyssier, J., Saenko, S. V., van der Marel, D. & Milinkovitch, M. C. Photonic crystals cause active colour change in chameleons. Nat. Commun. 6, 6368 (2015).

    Article  CAS  PubMed  Google Scholar 

  4. Stern, C. D. Gastrulation: From Cells to Embryo. (Cold Spring Harbor Laboratory Press, New York, 2004).

  5. Zhang, L., Marcos, V. & Leigh, D. A. Molecular machines with bio-inspired mechanisms. Proc. Natl Acad. Sci. U. S. A. 115, 9397–9404 (2018).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  6. Browne, W. R. & Feringa, B. L. Making molecular machines work. Nat. Nanotechnol. 1, 25–35 (2006).

    Article  CAS  PubMed  Google Scholar 

  7. Kay, E. R. & Leigh, D. A. Rise of the molecular machines. Angew. Chem. Int. Ed. 54, 10080–10088 (2015).

    Article  CAS  Google Scholar 

  8. Abendroth, J. M., Bushuyev, O. S., Weiss, P. S. & Barrett, C. J. Controlling motion at the nanoscale: rise of the molecular machines. ACS Nano 9, 7746–7768 (2015).

    Article  CAS  PubMed  Google Scholar 

  9. Balzani, V., Credi, A. & Venturi, M. Light powered molecular machines. Chem. Soc. Rev. 38, 1542–1550 (2009).

    Article  CAS  PubMed  Google Scholar 

  10. Balzani, V., Credi, A., Raymo, F. M. & Stoddart, J. F. Artificial molecular machines. Angew. Chem. Int. Ed. 39, 3348–3391 (2000).

    Article  CAS  Google Scholar 

  11. Erbas-Cakmak, S., Leigh, D. A., McTernan, C. T. & Nussbaumer, A. L. Artificial molecular machines. Chem. Rev. 115, 10081–10206 (2015).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  12. Peplow, M. The tiniest Lego: a tale of nanoscale motors, rotors, switches and pumps. Nature 525, 18–21 (2015).

    Article  CAS  PubMed  Google Scholar 

  13. Kassem, S. et al. Artificial molecular motors. Chem. Soc. Rev. 46, 2592–2621 (2017).

    Article  CAS  PubMed  Google Scholar 

  14. Feringa, B. L. The art of building small: from molecular switches to motors (Nobel lecture). Angew. Chem. Int. Ed. 56, 11060–11078 (2017).

    Article  CAS  Google Scholar 

  15. Leigh, D. A. Genesis of the nanomachines: the 2016 Nobel Prize in Chemistry. Angew. Chem. Int. Ed. 55, 14506–14508 (2016).

    Article  CAS  Google Scholar 

  16. Kholodenko, B. N. Cell-signalling dynamics in time and space. Nat. Rev. Mol. Cell Biol. 7, 165–176 (2006).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Novák, B. & Tyson, J. J. Design principles of biochemical oscillators. Nat. Rev. Mol. Cell Biol. 9, 981–991 (2008).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  18. Astumian, R. D. Design principles for Brownian molecular machines: how to swim in molasses and walk in a hurricane. Phys. Chem. Chem. Phys. 9, 5067–5083 (2007).

    Article  CAS  PubMed  Google Scholar 

  19. Astumian, R. D., Mukherjee, S. & Warshel, A. The physics and physical chemistry of molecular machines. ChemPhysChem 17, 1719–1741 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  20. Garcia-Garibay, M. A. Crystalline molecular machines: encoding supramolecular dynamics into molecular structure. Proc. Natl Acad. Sci. U. S. A. 102, 10771–10776 (2005).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  21. Uchida, K., Nishimura, R., Hatano, E., Mayama, H. & Yokojima, S. Photochromic crystalline systems mimicking bio-functions. Chem. Eur. J. 24, 8491–8506 (2018).

    Article  CAS  Google Scholar 

  22. Naumov, P., Chizhik, S., Panda, M. K., Nath, N. K. & Boldyreva, E. Mechanically responsive molecular crystals. Chem. Rev. 115, 12440–12490 (2015).

    Article  CAS  PubMed  Google Scholar 

  23. Khuong, T.-A. V., Nuñez, J. E., Godinez, C. E. & Garcia-Garibay, M. A. Crystalline molecular machines:  a quest toward solid-state dynamics and function. Acc. Chem. Res. 39, 413–422 (2006).

    Article  CAS  PubMed  Google Scholar 

  24. Irie, M., Fukaminato, T., Matsuda, K. & Kobatake, S. Photochromism of diarylethene molecules and crystals: memories, switches, and actuators. Chem. Rev. 114, 12174–12277 (2014).

    Article  CAS  PubMed  Google Scholar 

  25. Kobatake, S., Takami, S., Muto, H., Ishikawa, T. & Irie, M. Rapid and reversible shape changes of molecular crystals on photoirradiation. Nature 446, 778–781 (2007).

    Article  CAS  PubMed  Google Scholar 

  26. Koller, D. & Van Volkenburgh, E. The Restless Plant. (Harvard University Press, Cambridge, MA, 2011).

    Book  Google Scholar 

  27. Hofhuis, H. et al. Morphomechanical innovation drives explosive seed dispersal. Cell 166, 222–233 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Hatano, E. et al. Photosalient phenomena that mimic Impatiens are observed in hollow crystals of diarylethene with a perfluorocyclohexene ring. Angew. Chem. Int. Ed. 56, 12576–12580 (2017).

    Article  CAS  Google Scholar 

  29. Medishetty, R. et al. Single crystals popping under UV light: a photosalient effect triggered by a [2+2] cycloaddition reaction. Angew. Chem. Int. Ed. 53, 5907–5911 (2014).

    Article  CAS  Google Scholar 

  30. Zhu, L., Al-Kaysi, R. O. & Bardeen, C. J. Reversible photoinduced twisting of molecular crystal microribbons. J. Am. Chem. Soc. 133, 12569–12575 (2011).

    Article  CAS  PubMed  Google Scholar 

  31. Aspuru-Guzik, A. et al. Charting a course for chemistry. Nat. Chem. 11, 286–294 (2019).

    Article  CAS  PubMed  Google Scholar 

  32. Gennes, P. G. de. & Prost, J. The Physics of Liquid Crystals. (Clarendon Press, Oxford, 1993).

    Google Scholar 

  33. Kleman, M. & Lavrentovich, O. Soft Matter Physics: An Introduction. (Springer, New York, 2004).

    Book  Google Scholar 

  34. Eelkema, R. & Feringa, B. L. Amplification of chirality in liquid crystals. Org. Biomol. Chem. 4, 3729–3745 (2006).

    Article  CAS  PubMed  Google Scholar 

  35. Kitzerow, H. & Bahr, C. Chirality in Liquid Crystals. (Springer-Verlag, New York, 2001).

    Book  Google Scholar 

  36. Liu, D. & Broer, D. J. Liquid crystal polymer networks: preparation, properties, and applications of films with patterned molecular alignment. Langmuir 30, 13499–13509 (2014).

    Article  CAS  PubMed  Google Scholar 

  37. White, T. J. & Broer, D. J. Programmable and adaptive mechanics with liquid crystal polymer networks and elastomers. Nat. Mater. 14, 1087–1098 (2015).

    Article  CAS  PubMed  Google Scholar 

  38. Ryabchun, A., Li, Q., Lancia, F., Aprahamian, I. & Katsonis, N. Shape-persistent actuators from hydrazone photoswitches. J. Am. Chem. Soc. 141, 1196–1200 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  39. Bandara, H. M. D. & Burdette, S. C. Photoisomerization in different classes of azobenzene. Chem. Soc. Rev. 41, 1809–1825 (2012).

    Article  CAS  PubMed  Google Scholar 

  40. Schultz, T. et al. Mechanism and dynamics of azobenzene photoisomerization. J. Am. Chem. Soc. 125, 8098–8099 (2003).

    Article  CAS  PubMed  Google Scholar 

  41. Tsutsumi, O., Shiono, T., Ikeda, T. & Galli, G. Photochemical phase transition behavior of nematic liquid crystals with azobenzene moieties as both mesogens and photosensitive chromophores. J. Phys. Chem. 101, 1332–1337 (1997).

    Article  CAS  Google Scholar 

  42. Matczyszyn, K. & Sworakowski, J. Phase change in azobenzene derivative-doped liquid crystal controlled by the photochromic reaction of the dye. J. Phys. Chem. B 107, 6039–6045 (2003).

    Article  CAS  Google Scholar 

  43. Liu, D. & Broer, D. J. Liquid crystal polymer networks: switchable surface topographies. Liq. Cryst. Rev. 1, 20–28 (2013).

    Article  CAS  Google Scholar 

  44. Ikeda, T., Mamiya, J. & Yu, Y. Photomechanics of liquid-crystalline elastomers and other polymers. Angew. Chem. Int. Ed. 46, 506–528 (2007).

    Article  CAS  Google Scholar 

  45. Ube, T. & Ikeda, T. Photomobile polymer materials with crosslinked liquid-crystalline structures: molecular design, fabrication, and functions. Angew. Chem. Int. Ed. 53, 10290–10299 (2014).

    Article  CAS  Google Scholar 

  46. Yu, Y., Nakano, M. & Ikeda, T. Directed bending of a polymer film by light. Nature 425, 145–145 (2003).

    Article  CAS  PubMed  Google Scholar 

  47. Zhao, Y. & Ikeda, T. Smart Light-Responsive Materials: Azobenzene-Containing Polymers and Liquid Crystals. (Wiley, Hoboken, NJ, 2009).

    Book  Google Scholar 

  48. Priimagi, A. et al. Location of the azobenzene moieties within the cross-linked liquid-crystalline polymers can dictate the direction of photoinduced bending. ACS Macro Lett. 1, 96–99 (2011).

    Article  CAS  Google Scholar 

  49. Dong, L. & Zhao, Y. Photothermally driven liquid crystal polymer actuators. Mater. Chem. Front. 2, 1932–1943 (2018).

    Article  CAS  Google Scholar 

  50. Lahikainen, M., Zeng, H. & Priimagi, A. Reconfigurable photoactuator through synergistic use of photochemical and photothermal effects. Nat. Commun. 9, 4148 (2018).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  51. Pei, Z. et al. Mouldable liquid-crystalline elastomer actuators with exchangeable covalent bonds. Nat. Mater. 13, 36–41 (2014).

    Article  CAS  PubMed  Google Scholar 

  52. Darwin, C. & Darwin, F. The Power of Movement in Plants. (Cambridge University Press, Cambridge, 2009).

  53. Isnard, S., Cobb, A. R., Holbrook, N. M., Zwieniecki, M. & Dumais, J. Tensioning the helix: a mechanism for force generation in twining plants. Proc. R. Soc. B Biol. Sci. 276, 2643–2650 (2009).

    Article  Google Scholar 

  54. Mahadevan, L. & Matsudaira, P. Motility powered by supramolecular springs and ratchets. Science 288, 95–100 (2000).

    Article  CAS  PubMed  Google Scholar 

  55. Armon, S., Efrati, E., Kupferman, R. & Sharon, E. Geometry and mechanics in the opening of chiral seed pods. Science 333, 1726–1730 (2011).

    Article  CAS  PubMed  Google Scholar 

  56. Elbaum, R. & Abraham, Y. Insights into the microstructures of hygroscopic movement in plant seed dispersal. Plant Sci. 223, 124–133 (2014).

    Article  CAS  PubMed  Google Scholar 

  57. Iamsaard, S. et al. Conversion of light into macroscopic helical motion. Nat. Chem. 6, 229–235 (2014).

    Article  CAS  PubMed  Google Scholar 

  58. Iamsaard, S. et al. Preparation of biomimetic photoresponsive polymer springs. Nat. Protoc. 11, 1788–1797 (2016).

    Article  CAS  PubMed  Google Scholar 

  59. Aßhoff, S. J. et al. High-power actuation from molecular photoswitches in enantiomerically paired soft springs. Angew. Chem. Int. Ed. 56, 3261–3265 (2017).

    Article  CAS  Google Scholar 

  60. Purcell, E. M. Life at low Reynolds number. Am. J. Phys. 45, 3–11 (1977).

    Article  Google Scholar 

  61. van Oosten, C. L., Bastiaansen, C. W. M. & Broer, D. J. Printed artificial cilia from liquid-crystal network actuators modularly driven by light. Nat. Mater. 8, 677–682 (2009).

    Article  PubMed  CAS  Google Scholar 

  62. Wani, O. M., Verpaalen, R., Zeng, H., Priimagi, A. & Schenning, A. P. H. J. An artificial nocturnal flower via humidity-gated photoactuation in liquid crystal networks. Adv. Mater. 31, 1805985 (2019).

    Article  CAS  Google Scholar 

  63. Wani, O. M., Zeng, H. & Priimagi, A. A light-driven artificial flytrap. Nat. Commun. 8, 15546 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  64. Martin, N. et al. Light-induced dynamic shaping and self-division of multipodal polyelectrolyte-surfactant microarchitectures via azobenzene photomechanics. Sci. Rep. 7, 41327 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  65. Chen, J. et al. Artificial muscle-like function from hierarchical supramolecular assembly of photoresponsive molecular motors. Nat. Chem. 10, 132–138 (2017).

    Article  PubMed  CAS  Google Scholar 

  66. Koumura, N., Zijlstra, R. W. J., van Delden, R. A., Harada, N. & Feringa, B. L. Light-driven monodirectional molecular rotor. Nature 401, 152–155 (1999).

    Article  CAS  PubMed  Google Scholar 

  67. Koumura, N., Geertsema, E. M., Meetsma, A. & Feringa, B. L. Light-driven molecular motor:  unidirectional rotation controlled by a single stereogenic center. J. Am. Chem. Soc. 122, 12005–12006 (2000).

    Article  CAS  Google Scholar 

  68. Pollard, M. M., Klok, M., Pijper, D. & Feringa, B. L. Rate acceleration of light-driven rotary molecular motors. Adv. Funct. Mater. 17, 718–729 (2007).

    Article  CAS  Google Scholar 

  69. van Leeuwen, T., Lubbe, A. S., Štacko, P., Wezenberg, S. J. & Feringa, B. L. Dynamic control of function by light-driven molecular motors. Nat. Rev. Chem. 1, 0096 (2017).

    Article  CAS  Google Scholar 

  70. Camacho-Lopez, M., Finkelmann, H., Palffy-Muhoray, P. & Shelley, M. Fast liquid-crystal elastomer swims into the dark. Nat. Mater. 3, 307–310 (2004).

    Article  CAS  PubMed  Google Scholar 

  71. Sfakiotakis, M., Lane, D. M. & Davies, J. B. C. Review of fish swimming modes for aquatic locomotion. IEEE J. Ocean. Eng. 24, 237–252 (1999).

    Article  Google Scholar 

  72. Palagi, S. et al. Structured light enables biomimetic swimming and versatile locomotion of photoresponsive soft microrobots. Nat. Mater. 15, 647–653 (2016).

    Article  CAS  PubMed  Google Scholar 

  73. Wie, J. J., Shankar, M. R. & White, T. J. Photomotility of polymers. Nat. Commun. 7, 13260 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  74. Rus, D. & Tolley, M. T. Design, fabrication and control of soft robots. Nature 521, 467–475 (2015).

    Article  CAS  PubMed  Google Scholar 

  75. Rogóz˙, M., Zeng, H., Xuan, C., Wiersma, D. S. & Wasylczyk, P. Light-driven soft robot mimics caterpillar locomotion in natural scale. Adv. Opt. Mater. 4, 1689–1694 (2016).

    Article  CAS  Google Scholar 

  76. Zeng, H., Wani, O. M., Wasylczyk, P. & Priimagi, A. Light-driven, caterpillar-inspired miniature inching robot. Macromol. Rapid Commun. 39, 1700224 (2018).

    Article  CAS  Google Scholar 

  77. Goujon, A. et al. Bistable [c2] daisy chain rotaxanes as reversible muscle-like actuators in mechanically active gels. J. Am. Chem. Soc. 139, 14825–14828 (2017).

    Article  CAS  PubMed  Google Scholar 

  78. Iwaso, K., Takashima, Y. & Harada, A. Fast response dry-type artificial molecular muscles with [c2] daisy chains. Nat. Chem. 8, 625–632 (2016).

    Article  CAS  PubMed  Google Scholar 

  79. Takashima, Y. et al. Expansion–contraction of photoresponsive artificial muscle regulated by host–guest interactions. Nat. Commun. 3, 1270 (2012).

    Article  PubMed  CAS  Google Scholar 

  80. Li, Q. et al. Macroscopic contraction of a gel induced by the integrated motion of light-driven molecular motors. Nat. Nanotechnol. 10, 161–165 (2015).

    Article  PubMed  CAS  Google Scholar 

  81. Foy, J. T. et al. Dual-light control of nanomachines that integrate motor and modulator subunits. Nat. Nanotechnol. 12, 540–545 (2017).

    Article  CAS  PubMed  Google Scholar 

  82. Semenov, S. N. et al. Rational design of functional and tunable oscillating enzymatic networks. Nat. Chem. 7, 160–165 (2015).

    Article  CAS  PubMed  Google Scholar 

  83. Grzybowski, B. A. & Huck, W. T. S. The nanotechnology of life-inspired systems. Nat. Nanotechnol. 11, 585–592 (2016).

    Article  CAS  PubMed  Google Scholar 

  84. van Roekel, H. W. H. et al. Programmable chemical reaction networks: emulating regulatory functions in living cells using a bottom-up approach. Chem. Soc. Rev. 44, 7465–7483 (2015).

    Article  PubMed  Google Scholar 

  85. Smith, M. L., Slone, C., Heitfeld, K. & Vaia, R. A. Designed autonomic motion in heterogeneous Belousov–Zhabotinsky (BZ)-gelatin composites by synchronicity. Adv. Funct. Mater. 23, 2835–2842 (2013).

    Article  CAS  Google Scholar 

  86. Buskohl, P. R. & Vaia, R. A. Belousov-Zhabotinsky autonomic hydrogel composites: regulating waves via asymmetry. Sci. Adv. 2, e1600813 (2016).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  87. Sasaki, S., Koga, S., Yoshida, R. & Yamaguchi, T. Mechanical oscillation coupled with the Belousov−Zhabotinsky reaction in gel. Langmuir 19, 5595–5600 (2003).

    Article  CAS  Google Scholar 

  88. Yoshida, R. Self-oscillating gels driven by the Belousov–Zhabotinsky reaction as novel smart materials. Adv. Mater. 22, 3463–3483 (2010).

    Article  CAS  PubMed  Google Scholar 

  89. Gelebart, A. H. et al. Making waves in a photoactive polymer film. Nature 546, 632–636 (2017).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  90. White, T. J. et al. A high frequency photodriven polymer oscillator. Soft Matter 4, 1796–1798 (2008).

    Article  CAS  Google Scholar 

  91. Katsonis, N., Lacaze, E. & Ferrarini, A. Controlling chirality with helix inversion in cholesteric liquid crystals. J. Mater. Chem. 22, 7088–7097 (2012).

    Article  CAS  Google Scholar 

  92. Morrow, S. M., Bissette, A. J. & Fletcher, S. P. Transmission of chirality through space and across length scales. Nat. Nanotechnol. 12, 410–419 (2017).

    Article  CAS  PubMed  Google Scholar 

  93. Eelkema, R. et al. Nanomotor rotates microscale objects. Nature 440, 163–163 (2006).

    Article  CAS  PubMed  Google Scholar 

  94. Bosco, A. et al. Photoinduced reorganization of motor-doped chiral liquid crystals: bridging molecular isomerization and texture rotation. J. Am. Chem. Soc. 130, 14615–14624 (2008).

    Article  CAS  PubMed  Google Scholar 

  95. Eelkema, R. et al. Rotational reorganization of doped cholesteric liquid crystalline films. J. Am. Chem. Soc. 128, 14397–14407 (2006).

    Article  CAS  PubMed  Google Scholar 

  96. Aßhoff, S. J. et al. Time-programmed helix inversion in phototunable liquid crystals. Chem. Commun. 49, 4256–4258 (2013).

    Article  Google Scholar 

  97. Orlova, T. et al. Revolving supramolecular chiral structures powered by light in nanomotor-doped liquid crystals. Nat. Nanotechnol. 13, 304–308 (2018).

    Article  CAS  PubMed  Google Scholar 

  98. Fischer, P., Nalson, B. D. & Yang, G.-Z. New materials for next-generation robots. Science Robotics 3, eaau0448 (2018).

    Article  PubMed  Google Scholar 

  99. Boulatov, R. The challenges and opportunities of contemporary polymer mechanochemistry. ChemPhysChem 18, 1419–1421 (2017).

    Article  CAS  PubMed  Google Scholar 

  100. Anderson, L. & Boulatov, R. Polymer mechanochemistry: a new frontier for physical organic chemistry. Adv. Phys. Org. Chem. 52, 87–143 (2018).

    CAS  Google Scholar 

  101. Akbulatov, S. et al. Experimentally realized mechanochemistry distinct from force-accelerated scission of loaded bonds. Science 357, 299–303 (2017).

    Article  CAS  PubMed  Google Scholar 

  102. Davis, D. A. et al. Force-induced activation of covalent bonds in mechanoresponsive polymeric materials. Nature 459, 68–72 (2009).

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgements

The authors acknowledge funding support from the European Research Council (Consolidator Grant Morpheus 30968307) and the Netherlands Organization for Scientific Research (Projectruimte grant 13PR3105).

Author information

Authors and Affiliations

Authors

Contributions

F.L. and A.R. contributed equally to the manuscript. N.K. directed the project. All the authors contributed to the design, writing and editing of the article.

Corresponding author

Correspondence to Nathalie Katsonis.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information

Nature Reviews Chemistry thanks R. D. Astumian, 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.

Glossary

Artificial molecular machines

Man-made molecules or molecular systems that perform useful tasks by converting an energy input into a mechanically relevant motion.

Feedback loops

Effects that regulate a molecular signal, in space and time. This signal can be a mechanical signal, an electrical signal, an optical signal or, more classically, a concentration of molecules. The regulation mechanism can be based on a network of chemical reactions or on a series of mechanical events.

Liquid crystals

Molecules and materials that exhibit a liquid-crystalline state in specific conditions of temperature or dilution. The liquid-crystalline state is a consequence of molecular shape anisotropy and is characterized by a fluidity that is inherent to conventional liquids, combined with a long-range molecular orientation that is also found in crystals. This long-range organization can occur in solution (lyotropic phases) or in bulk materials (thermotropic phases).

Gels

Colloidal networks, polymer networks or supramolecular assemblies that are expanded throughout their whole volume (e.g. swollen) by a fluid and exhibit no flow when in the steady state.

Filter effect

The effect that limits the propagation of light through the thickness of a molecular material, by absorption or by scattering.

Photosalient effect

Accumulation of stress in bulk materials under continuous irradiation that leads to the abrupt release of kinetic energy via bursting, jumping, rolling, etc.

Liquid-crystal networks

Materials in which the physical properties of polymeric networks and high anisotropy inherent to the liquid-crystalline state are combined.

Nematic liquid crystals

Liquid crystals in which the long axes of the molecules align, on average, in one direction preferentially. This direction is defined as the director n (see Box 1).

Cholesteric liquid crystals

Liquid crystals in which the molecules are organized into a helix.

Photothermal effect

The production of heat by the dissipation of energy, when light is absorbed by molecules in solution or by a molecular material. When coupled to anisotropic media, the increase of temperature can result in the generation of an anisotropic, mechanical strain.

Planar alignment

The situation in which the long axes of the liquid-crystal molecules align parallel to the interface.

Homeotropic alignment

The situation in which the long axes of the liquid-crystal molecules align perpendicularly to the interface.

Supramolecular polymers

Polymers whose monomeric units hold together via highly directional and reversible, non-covalent interactions, including hydrogen bonding, π–π interaction, metal coordination and host–guest interaction.

Out of equilibrium

Description for processes that occur under a constant input of energy and, thus, remain away from thermodynamic equilibrium.

Negative feedback loop

A regulation mechanism by which the increase in the concentration of a product inhibits its own production.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Lancia, F., Ryabchun, A. & Katsonis, N. Life-like motion driven by artificial molecular machines. Nat Rev Chem 3, 536–551 (2019). https://doi.org/10.1038/s41570-019-0122-2

Download citation

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41570-019-0122-2

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