BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Memento EPFL//
BEGIN:VEVENT
SUMMARY:High-speed Force Microscopy and Holo 4π AFM for Biological System
 s
DTSTART:20150831T121500
DTSTAMP:20260510T204854Z
UID:675426af5c230c19859c8196cb99186b02dc277c7dd40785007abf77
CATEGORIES:Conferences - Seminars
DESCRIPTION:Prof. Mervyn Miles\, University of Bristol (UK)\nDISTINGUISHED
  LECTURE IN BIOLOGICAL ENGINEERING(sandwiches served)Abstract:\nAtomic for
 ce microscopy (AFM) is complementary to many other microscopies in biologi
 cal systems\, and offers many benefits such has high-resolution 3D imaging
  in many environments including liquids.  However\, there are three areas
  in which conventional AFM has serious limitations: (i) a low imaging rate
 \, (ii) the probe-sample force interaction\, and (iii) the planar nature o
 f the sample.\nWe are developing two high-speed force microscopy technique
 s to overcome the first two of these\, (i) and (ii).\n(i)  One high-speed
  AFM (HS AFM) technique is a DC mode in which an automatic feedback mechan
 ism\, essentially arising from the hydrodynamics of the situation\, mainta
 ins a tip-specimen separation of about 1 nm. This technique routinely allo
 ws video-rate imaging (30 frames per second\, fps) and has achieved unprec
 edented imaging rates at over 1000 fps\, i.e.\, 100\,000 times faster than
  conventional AFM. Damage to specimens resulting from this high-speed DC-m
 ode imaging is surprisingly less than would be caused at normal speeds. Th
 e behaviour of the cantilever and tip at these high velocities has been in
 vestigated and super lubrication is a key component in the success of this
  technique [1\,2].\n(ii) The other high-speed force microscope is a non-co
 ntact method based on shear-force microscopy (ShFM). In this HS ShFM\, a v
 ertically-oriented\, laterally-oscillating probe detects the sample surfac
 e at about 1 nm from it as a result of the change in the mechanical proper
 ties of the water confined between the probe tip and the sample. With this
  technique\, very low normal forces are applied to the specimen.  There i
 s a bonus of obtaining information on the structure of the molecular water
  layers as a function of position over the sample surface [3\,4].\n(iii) A
 FMs require planar samples because the probe scans in a plane.  It is as 
 if the tip is only ‘seeing’ the sample from above. We have overcome th
 is limitation by steering the tip of a nanorod in a three dimensional scan
  with six degrees of freedom using holographically generated traps such th
 at it is possible to scan around a sample from any direction.  Various pr
 obe types have been utilized\, including silica nanorods\, rod-like diatom
 s\, and custom designed\, two-photon polymerized 3D structures [5\,6].\n1.
  Payton\, OD\, et al.\, Nanotechnology 23 (2012) Art. No. 265702.\n2. Kalp
 etek\, P\, et al.\, Measurement Sci. & Technol.\, 24 (2013) Art. No. 02500
 6.\n3. Harniman RL\, et al.\, Nanotechnology 23 (2012) Art. No. 085703.\n4
 . Fletcher\, J\, et al.\, Science 340 (2013) online April 11th.\n5. Philli
 ps DB\, et al.\, Nanotechnology 22 (2011) Art. No. 285503.\n6. Olof SN et 
 al.\, Nano Letters 12 (2012) 6018-6023.Bio:\nAbout the speaker:   Dr. Me
 rvyn Miles is Professor of Physics and Head of the Nanophysics and Soft Ma
 tter Group at the University of Bristol (UK)\, Fellow of the Royal Society
  and holder of the Royal Society Wolfson Research Merit Award.\nDr. Miles 
 is distinguished for the development of a number of revolutionary new tech
 niques of scanning-probe microscopy and demonstrating their potential for 
 breaking into new areas of research in the study of biomolecular and polym
 er systems. One of these permits\, for the first time\, the study of dynam
 ic changes in many systems of critical interest achieved through imaging r
 ates of more than 100 frames per second\, fast enough to follow previously
  inaccessible biomolecular processes and to fabricate nanoscale structures
 . A second is a unique form of force microscopy that senses the specimen s
 urface through a few atomic layers of water molecules without mechanical c
 ontact\, ideal for studying delicate biological structures at high resolut
 ion. A third involves adjustment of the damping of an atomic force cantile
 ver in a liquid environment so as to improve sensitivity\, significantly e
 nhancing the rate of imaging and reducing the damage caused to soft materi
 als.\nKeywords applying to research in the Miles Lab:\nAtomic force micros
 copy\, scanning tunnelling microscopy\, scanning near-field optical micros
 copy\, high-speed AFM\, high-speed non-contact AFM\, holographic optical t
 weezer\, optical AFM\, polymers\, biomolecules
LOCATION:SV1717a http://map.epfl.ch/?room=sv1717a
STATUS:CONFIRMED
END:VEVENT
END:VCALENDAR