BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Memento EPFL//
BEGIN:VEVENT
SUMMARY:MechE Colloquium: Making and measuring the most slippery water-rep
 ellent surfaces
DTSTART:20260224T120000
DTEND:20260224T130000
DTSTAMP:20260524T212929Z
UID:0fae25058ebc82bf496c154f67953b2166d06697dcdfa4177a83ad8d
CATEGORIES:Conferences - Seminars
DESCRIPTION:Prof. Robin Ras\, Department of Applied Physics\, Aalto Univ
 ersity\nAbstract: Water-repellent surfaces have the attractive property o
 f staying dry\, and find applications in self-cleaning\, anti-icing\, anti
 -fogging and much more. These surfaces stay dry because water droplets exp
 erience low friction and slide off easily at low tilt angles.[1]\nSurface 
 heterogeneity is generally acknowledged as the major cause of contact angl
 e hysteresis and friction of droplets. Here we evaluate this long-standing
  premise for chemical heterogeneity at the molecular length scale. It is o
 ften assumed that achieving low sliding angles on water-repellent surfaces
  requires hydrophobicity\, in other words high water contact angle like fo
 r example teflon. We challenge this assumption and demonstrate a hydrophil
 ic alkyltrichlorosilane self-assembled monolayer featuring the unusual com
 bination of low sliding angle and low contact angle. By coating a nanotext
 ured surface with hydrophobic self-assembled monolayer\, we obtain extraor
 dinarily low droplet friction.[2] \nA major bottleneck to real-world appl
 ications of superhydrophobic surfaces has been their fragility. By suitabl
 e design of surface textures\, we demonstrate extreme mechanical durabilit
 y of superhydrophobic surfaces.[3]\nFinally\, because contact angle goniom
 etry has inherent limitations in accuracy [4]\, we have developed highly s
 ensitive methods to study droplet friction and adhesion.[5\,6]\n   
    \nReferences\n1.    L. Chen\, S. Huang\, R. H. A. Ras\, X
 . Tian\, Omniphobic liquid-like surfaces\, Nature Chemistry Reviews\, (202
 3) 123-137. https://doi.org/10.1038/s41570-022-00455-w \n2.    S.
  Lepikko\, Y. Morais Jaques\, M. Junaid\, M. Backholm\, J. Lahtinen\, J. J
 ulin\, V. Jokinen\, T. Sajavaara\, M. Sammalkorpi\, A. S. Foster\, R. H. A
 . Ras\, Droplet slipperiness despite surface heterogeneity at molecular sc
 ale\, Nature Chemistry (2024). https://doi.org/10.1038/s41557-023-01346-3
  \n3.   Wang D.\, Sun Q.\, Hokkanen M.J.\, Zhang C.\, Lin F.-Y.\, L
 iu Q.\, Zhu S.-P.\, Zhou T.\, Chang Q.\, He B.\, Zhou Q.\, Chen L.\, Wang 
 Z.\, Ras R.H.A.\, Deng X.\, Design of Robust Superhydrophobic Surfaces\, N
 ature 582\, 55–59 (2020).  https://www.nature.com/articles/s41586-020-2
 331-8\n4.    Liu K.\, Vuckovac M.\, Latikka M.\, Huhtamäki T.\, Ras
  R.H.A.\, Improving surface-wetting characterization\, Science 363\, 1147
 −1148 (2019). https://doi.org/10.1126/science.aav5388\n5.    Liima
 tainen V.\, Vuckovac M.\, Jokinen V.\, Sariola V.\, Hokkanen M.\, Zhou Q.\
 , Ras R.H.A.\, Mapping microscale wetting variations on biological and syn
 thetic water-repellent surfaces\, Nature Communications 8\, 1798 (2017). h
 ttp://dx.doi.org/10.1038/s41467-017-01510-7\n6.    Daniel D.\, Vucko
 vac M.\, Backholm M.\, Latikka M.\, Karyappa R.\, Koh X. Q.\, Timonen J. V
 . I.\, Tomczak N.\, Ras R. H. A.\, Probing surface wetting across multiple
  force\, length and time scales\, Communications Physics 6\, 152 (2023). 
  https://doi.org/10.1038/s42005-023-01268-z\n\nBiography: Robin Ras head
 s the Soft Matter and Wetting research group at Department of Applied Phys
 ics\, Aalto University (Finland). His research area is situated at the int
 erface between physics\, chemistry and materials science\, dealing with fu
 ndamental scientific problems and technological applications. He has autho
 red over 170 scientific publications. Robin Ras received the ERC Consolida
 tor grant for research on extremely water-repellent surfaces (2017-2022). 
 He received the Anton Paar Research Award for Instrumental Analytics & Cha
 racterization (2018) for the invention Scanning Droplet Adhesion Microscop
 y. He obtained his Ph.D. degree in Bioscience Engineering – Chemistry at
  the University of Leuven\, Belgium in 2003.
LOCATION:MED 0 1418 https://plan.epfl.ch/?room==MED%200%201418 https://epf
 l.zoom.us/j/61360740951
STATUS:CONFIRMED
END:VEVENT
END:VCALENDAR