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SUMMARY:Viscous flow engineering: a novel approach for the scalable fabric
 ation of advanced multi-material fibers and metasurfaces
DTSTART:20171208T151500
DTSTAMP:20260407T210934Z
UID:a32aff215668f8f2c263ca5496909469c6e35b0f7cb0bceaea66d0a3
CATEGORIES:Conferences - Seminars
DESCRIPTION:Prof. Fabien Sorin\, STI\nBio: Since March 2013\, he has been 
 in the Institute of Materials Science (IMX) at the Ecole Polytechnique Fé
 dérale de Lausanne (EPFL) as an assistant professor “tenure-track”. He 
 is starting a research group on photonic materials and fiber devices (FIMA
 P)\, continuing on developing innovative materials processing approaches a
 nd photonic device architectures to develop new solutions in energy harves
 ting\, saving and storage\, in sensing and monitoring\, health care and sm
 art fabrics.\nCondensed Matter Physics Seminar\n\nThe dewetting of thin po
 lymeric films and the thermal drawing of polymer and glass fibers are two
  seemingly very different processes. They can however both be described 
 for a large part via an interplay between viscosity and surface tension [
 1]. In this talk\, we will first show how we can control the solid-state 
 dewetting of thin\, high refractive index optical glass layers onto patt
 erned polymer substrates to realize high–quality optical metasurfaces. 
 We will investigate how the interplay between viscous flow at the nanosc
 ale and surface tension enables to tailor the size and shape of chaclogen
 ide glasses nano-objects and hence control their optical properties. Seco
 nd\, we will present how we can apply similar principles to the process 
 of thermal drawing – the same process used to fabricate optical fibers 
 – to realize multi-material fibers and ribbons with advanced optical a
 nd electronic functionalities [2].\n\nIn particular\, we will show how we
  can fabricate thin and flexible fibers with sub-micrometer surface patte
 rns by tailoring the materials surface tension. We will then demonstrate
  how applying this understanding to electrically conducting polymer nano
 -composites can lead to intriguing fiber devices such as electromechanica
 l one-dimensional distributed touch sensors [3]. Turning to semiconducto
 r-based fibers\, we will show how modifying the surface energy of semico
 nducting materials in solution can enable the fabrication of single-cryst
 al nanowire-based optoelectronic fibers with unprecedented performance [4
 ]. \n\nFinally\, we propose for the first time to tailor the viscosity o
 f materials during thermal drawing by looking at rheological and microstr
 uctural attributes at a deeper level. We will in particular show how we 
 could identify some elastomeric materials that can be drawn with flow pro
 perties similar to their thermoplastic counterparts. This opens novel op
 portunities for fiber-based devices in the fields of stretchable optics an
 d electronics as well as biological probes and smart textiles.\n\nReferen
 ces\n[1] M. Schmidt et al. Advanced Optical Materials\, 2016\, 4\, 13.
 \n[2] T. Nguyen et al. Advanced Functional Materials\, 2017\, 27\, 160
 5935.\n[3] T. Nguyen et al. J. of Physics D: Appl. Phys.\, 2017\, 50
 \, 144001.\n[4] W. Yan et al\, Advanced Materials\, 2017\, 29\, 170068
 1.\nAbout the research of the speaker: https://fimap.epfl.ch\n 
LOCATION:CE 1 5 https://plan.epfl.ch/?room==CE%201%205
STATUS:CONFIRMED
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