Basel Universität

Guilherme Vilhena

PhD in Physics
office 3.04
tel +41 (0)61 207 3730


Research interests

Friction is a phenomenon which is present in our everyday life although we tend to remember it only when it is nearly absent such as
when “slipping on a banana peel”. Its presence across disparate length scales (earthquakes, car engines down to molecular machines)
reminds us of its ubiquity which endows friction of an utmost practical importance. Therefore, attempts to control it are almost as old
as civilization. Interestingly, during the past decades we have witnessed a growing progress in miniaturization of devices down to the
nanometer scale. “Special problems occur when things get small [...] and it might turn out to be advantages if we knew how to design for
them”, said Feynman when discussing the prospects of building “infinitesimal machinery”. To achieve this goal, and to design efficient
molecular nano-engines, it becomes imperative to know how friction at a molecular level can be controlled. We propose to address this
challenge by tuning molecular friction and adhesion via atomic/chemical design. Specifically, we shall study the lifting and sliding of
two template molecules (porphyrin and terpyridine) over a Gold (111) surface. These molecules contain substituents groups that act as
spinning molecular wheels when sliding over a surface. By proper modifications of these groups (wheels) we can tune the grip/drift response
and the efficiency of the ball bearing over which the molecular wheel spins. Here we aim to provide an atomic level understanding of these
processes by combining state-of-the-art molecular dynamics simulations with high resolution scanning-probe microscopy experiments
conducted in ultra-high-vacuum conditions at low temperature. This will constitute a major step forward in our understanding of dissipation
processes at the nanoscale and paves the way to tune molecular friction and adhesion by atomic/chemical design.



Latest Papers (show all)

Slippery in every direction
J.G. Vilhena and Rubén Pérez
Nature Materials, 17, (10), (2018), 852-854, pdf.
Stick-Slip Motion of ssDNA over Graphene
J.G. Vilhena, E. Gnecco, R. Pawlak, F. Moreno-Herrero, E. Meyer, R. Pérez
J. Phys. Chem. B, (doi:10.1038/s41467-0), (2017), 787, pdf.

Latest Talks (show all)

"Snake-Like" motion of of a single poly-pyrene chain sliding on gold.
J.G. Vilhena , Remy Pawlak, Philipp D’Astolfo, Tobias Meier, Shi-Xia Liu, Silvio Decurtins, Enrico Gnecco, Alexis Baratoff, Rúben Pérez, Ernst Meyer
NC-AFM 2018, 2018-09-17, Porvoo, (Finland), Abstract (PDF).
Understanding/Tuning the transport properties of biomolecules atom by atom
J.G. Vilhena, Maria Ortega, C. R J.G. Vilhena
CECAM/Psi-k research conference: BioMolecular Electronics (BIOMOLECTRO), 2018-08-27, Madrid, (Spain), Abstract (PDF).

Latest Poster (show all)

Conformations and cryo-force spectroscopy of spray-deposited single-strand DNA on gold
J.G. Vilhena, Remy Pawlak, Antoine Hinaut, Tobias Meier, Thilo Glatzel, Alexis Baratoff, Enrico Gnecco, Ruben Perez and Ernst Meyer
Temperature Scaling of Contact Ageing Rates
J.G. Vilhena, Matthias Vorholzer, Ruben Perez, Enrico Gnecco, Dirk Dietzel and Andre Schirmeisen
Emergence of surface and interface structure from friction, fracture and deformation, 2018-07-27, Lausanne, (Switzerland), Abstract (PDF).