The work provides an experimental validation of a biomimetic approach that has been conceptualized for years in nanoscience and the researchers believe this broadens applications in robotics, information storage and obviously artificial muscles themselves.
Nature manufactures numerous machines that are molecular. Highly complex assemblies of proteins are involved in essential functions of living beings such as the transport of ions, the synthesis of ATP (the “energy molecule”), and cell division. Our muscles are controlled by the coordinated movement of these thousands of protein nano-machines, which only function individually over distances of the order of a nanometer. However, when combined thousands, such nano-machines amplify this telescopic movement until they reach our scale and do so in a coordinated manner.
Synthetic chemists have made progress over the last few years in the manufacture of artificial nano-machines but the coordination of several of these machines in space and time had not been achieved, the researchers say.
Nicolas Giuseppone, professor at the Université de Strasbourg, and his team have succeeded in synthesizing long polymer chains incorporating, via supramolecular bonds - an interaction between different molecules that is not based on a traditional “covalent” chemical bond but instead on what are known as “weak interactions”, thereby constituting complex molecular structures. Thousands of nano-machines, each capable of producing linear telescopic motion of around one nanometer. Under the influence of pH, their simultaneous movements allow the whole polymer chain to contract or extend over about 10 micrometers, thereby amplifying the movement by a factor of 10,000, along the same principles as those used by muscular tissues.
Precise measurements of this experimental feat have been performed in collaboration with the team led by Eric Buhler, a physicist specialized in radiation scattering at the Laboratoire Matière et Systèmes Complexes (CNRS/Université Paris Diderot).
These results, obtained using a biomimetic approach, could lead to numerous applications for the design of artificial muscles, micro-robots or the development of new materials incorporating nano-machines endowed with novel multi-scale mechanical properties.
Citation: Muscle-like Supramolecular Polymers – Integrated Motion from Thousands of Molecular Machines, G. Du, E. Moulin, N. Jouault, E. Buhler, N. Giuseppone, Angew. Chem. Int. Ed. On line on the 18/10/2012 (DOI: 10.1002/ange.201206571).