In 2013, GNS proposed the organization of a molecule-car race (http://www.cemes.fr/Molecule-car-Race) involving different molecule-vehicles driven one by one, at the same time, by pilots using different scanning tunneling microscopes (STM) but on the same surface [1]. This proposal is the consequence of a long period of GNS research on single molecule mechanics started long ago with the first observation of a single molecule in rotation [2] and followed by the construction of a few molecule(s) machinery like the single molecule-wheelbarrow [3], the molecular rack and pinion [4], the controlled rotation of a single molecule-rotor [5] and the first observation that a single molecule alone has enough power to rotate one way a few atoms [6] or another molecule [7]. This is also the consequence of the GNS long term vision concerning Atomic Scale Technologies (or Atomic Precise Manufacturing) where multiple planar atomic scale precise accesses to a single molecule or to a surface atom by atom fabricated circuits are constantly developed by GNS (see section Atomic scale technologies) for electronics, mechanics, magnetics and optics.
With about 100 atoms, a molecule-vehicle has by definition a chassis equipped with spacer chemical groups to hold it a few angstrom away from the surface, paddles, switchable legs or wheels and a motorization embedded on board [1]. For the first edition of the nanocar Race, pushing its molecule-vehicle using the known pushing, pulling or sliding STM manipulation modes was forbidden forcing each registered team to play with inelastic tunneling and electric field effects for a drive on the Au(111) or Ag(111) surfaces [8]. The 27th of April 2017 at 11:00 am, the departure flag was up in the Toulouse GNS Pico-Lab control room with the 6 selected teams on their starting atomic line, ready to nano-race (see photo below and http://nanocar-race.cnrs.fr).
The anticipated in 2013 run was 100 nm on a metallic surface with 2 turns (http://www.cemes.fr/Molecule-car-Race). On the 29th of April 2017 at 17:00 pm and after 2 days and one night of intense efforts, the first ever international nano-car race was a success.
It requires new UHV technologies created on purpose by GNS for this race involving in particular a unique LT-UHV 4-STM i.e. a scanning tunneling microscope with 4 scanners able to scan on the same surface and a special UHV sublimation system with a dedicated masking set-up.
GNS participated to its nanocar race with a unique molecule-vehicle whose chemical structure was based on a central curved chassis and four wheels [9]. The molecules were flash sublimated on an Au(111) surface and imaged at low temperature using the scanning tunneling microscope of the LT-UHV 4-STM dedicated to its drive. The curved conformation of the chassis and the consequent moderate interactions of the four wheels with the Au(111) surface have been observed. The dI/dV constant current maps of the tunneling electronic resonances close to the Au(111) Fermi level were recorded to identify the potential energy entry port on the molecular skeleton to trigger and control a driving of the molecule on the Au(111) surface [10].
A lateral pushing mode of molecular manipulation and the consequent recording of the manipulation signals confirm that the wheels can step by step rotate while passing over the Au(111) surface native herringbone reconstructions. Switching a phenyl holding a wheel to the chassis on a given axle was not observed for triggering a lateral molecular motion inelastically. This points out the necessity to encode the sequence of the required wheels action on the profile of potential energy surface of the excited states to be able to drive a molecule-vehicle.
In 2018, GNS announced the organization of the second edition of the International nano-car race for spring 2021 under the MEMO (Mechanics with molecule(s)) European project. Twenty three teams have declared their interest to participate from all over the world. End on 2019, 10 teams are officially registered and are activally preparing their molecule-vehicle [10]. The GNS Toulouse team in collaboration with Nara University in Japan are preparing their new molecule-car.
References
[1] : C. Joachim, G. Rapenne, ACS Nano, 7, 11-14 (2013).
[2] : J.K. Gimzewski, C. Joachim, R.R. Schlittler, V. Langlais, H. Tang, J. Johanson,
Science, 281, 531 (1998).
[3] : C. Joachim, H. Tang, F. Moresco, G. Rapenne, G. Meyer, Nanotechnology, 13, 330 (2002).
[4] : F. Chiaravalloti, L. Gross, K.H. Rieder, S. Stojkovic, A. Gourdon, C. Joachim, F. Moresco, Nature Mat., 6, 30 (2007).
[5] : U.G.E. Perera, F. Ample, H. Kersell, Y. Zhang, G. Vives, J. Echeverria, M. Grisolia, G. Rapenne, C. Joachim, S.-W. Hla, Nature Nano, 8, 46 (2013).
[6] : R. Ohmann, J. Meyer, A. Nickel, J. Echevaria, C. Joachim, F. Moresco, G. Cuniberti,, ACS Nano, 9, 8394 (2015).
[7] : P. Mishra, J.P. Hiel, W.V. Rossom, S. Yoshizawa, M. Grisolia, J. Echeveria, T. Ono, K. Ariga, T.Nakayama, C. Joachim, T. Uchihashi, NanoLett., 15, 4793 (2015).
[8] : F. Eisenhut, C. Durand, F. Moresco, J.P. Launay, C. Joachim, Eur. Phys. J. AP, 76, 10001 (2016).
[9] : H.P. Jacquot de Rouville, R. Garbage, R.E. Cook, A.R. Pujol, A.M. Sirven, G. Rapenne, Chem. Eur. J. 8, 3023 (2012).
[10] : W.-H. Soe, C. Durand, O. Guillermet, S. Gauthier, H.-P. Jacquot de Rouville, S. Srivastava, C. Kammerer, G. Rapenne and C. Joachim, Nanotechnology, 7, 495401 (2018).