[institut] Семинар: Оливиер Ноел, четвртак 30. новембар 11ч - SCL Seminar: Olivier Noel, Thursday, 30 November, 11:00

[Igor Stankovic]

Поштоване колеге,

Са задовољством вас позивам на семинар Лабораторије за примену рачунара 
у науци Центра за изучавање комплексних система у четвртак 30. новембра 
у 11:00 у читаоници библиотеке "др Драган Поповић" Института за физику у 
Београду. Наслов предавања је

Улога атхезије у механизмима нано-трења,

који ће одржати др Оливиер Ноел (Група за молекуларне пејзаже и 
биофотонику, Универзитетa Мен, Ле Ман, Француска).

У наставку је позив на енглеском и апстракт предавања.

Срдачан поздрав,

Игор Станковић

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Dear colleagues,

It is my pleasure to invite you to the SCL seminar of the Center for the 
Study of Complex Systems, which will be held on Thursday, November 30 
2017 at 11:00 in the library reading room "Dr Dragan Popović" of the 
Institute of Physics Belgrade. The talk entitled

"The role of adhesion in nano-friction mechanisms"

will be given by Dr Olivier Noel (IMMM, Molecular Landscapes and 
Biophotonic Horizons Group, University of Maine, UMR CNRS, Le Mans, 
France).

Abstract of the talk:

At the nano-scale, the AFM has proven to be an efficient tool to measure 
the adhesion force with a high resolution and a mono-asperity contact 
between the AFM probe and the surface is easily achieved. But, with a 
commercial AFM, the scanning imposes a back and forth movement of the 
probe relative to the surface which results in the halt of the 
displacement when the probe reaches its limit of displacement in one 
direction and needs to invert its scanning direction. During these rest 
periods, the contact between the probe and the sample may evolve and no 
stationary state is achieved. For example, in the case of capillary 
adhesion, the interval of time of the halt period typically of a few 
milliseconds is enough to form a water meniscus between the probe and 
the sample [1], while, in the case of viscous materials, creep can 
occur. In order to overcome these limitations, we have developed an 
innovative AFM mode called the AFM circular mode (or CM-AFM) [2] 
generating a circular motion of the AFM probe in the plane of the 
surface to get a continuous motion with no rest periods and a sliding 
nano-contact in a stationary state is easily obtained. In the seminar, I 
will show that the CM-AFM is unavoidable to investigate tribological 
properties of hydrophilic rigid materials or viscoelastic materials. In 
particular, I will show that capillary adhesion and viscoelasticity 
plays an important role in the dynamic friction mechanisms.

[1] O.Noel et al., Phys. Rev. Lett., 108 (2012) 015503
[2] H. Nasrallah et al., Rev. Scie. Instrum. 82 (2011) 113703.

Yours sincerely,

Igor Stankovic

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Scientific Computing Laboratory

Institute of Physics Belgrade
University of Belgrade

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