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SUMMARY:Bioinspired Nano- and Microstructured Surfaces: From Analysis and 
 Replication to Applications - Prof. Dr. Hendrik Hoelscher (Karlsruhe Insti
 tute of Technology\, Institute of Microstructure Technology\, Germany)
DTSTART:20200226T140000Z
DTEND:20200226T150000Z
UID:TALK138817@talks.cam.ac.uk
CONTACT:Lingtao Kong
DESCRIPTION:Many nano- and microstructured surfaces found in nature can se
 rve as an inspiration for im-proving technical applications. Although most
  biomimetic archetypes can be replicated with advanced techniques on a lab
 -scale\, it remains a challenge to develop processes for large-scale fabri
 cation techniques appropriate for commercial applications. Here\, I review
  some recent approaches with high potential for up-scaling. \n\nThe super-
 hydrophobic surfaces of water ferns like Salvinia and Pistia can be mimick
 ed with nanofur\, a dense fur of nanoscale hair hot pulled from polymer su
 rfaces. This fractal surface can be utilized as a coating for solar cells 
 and OLEDS. It enables self-cleaning while improv-ing optical efficiency at
  the same time [1\, 2]. \n\nThe scales of the black butterfly Pachliopta a
 ristolochiae are micro- and nanostructured and harvest sunlight over a wid
 e spectral and angular range. We fabricated such bio-inspired ab-sorbers u
 sing a scalable\, self-assembly patterning technique based on the phase se
 paration of a binary polymers mixture. Such nano-patterned absorbers achie
 ve a relative integrated ab-sorption increase of 90% at normal incident an
 gle of light to as high as 200% at large incident angles [3].\n\nWhite bee
 tles of the genus Cyphochilus are well-known for their scales producing a 
 nearly perfect whiteness in a very efficient way with an astonishing low a
 mount of material. Inspired by this biological architecture\, we developed
  two techniques allowing for the fabrication of ultra-thin\, yet highly sc
 attering\, white polymer films. Both approaches can be utilized for vari-o
 us applications ranging from extremely white but ultra-thin coatings to sc
 attering particles as potential replacements for titanium dioxide.\n\n[1] 
 	F. Vüllers\, G. Gomard\, J. B. Preinfalk\, E. Klampaftis\, M. Worgull\, 
 B. S. Richards\, H. Hölscher\, M. N. Ka-valenka\, Bioinspired Superhydrop
 hobic Highly Transmissive Films for Optical Applications\, Small 12\, 6144
 –6152 (2016)\n\n[2]	F. Vüllers\, B. Fritz\, A. Roslizar\, A. Striegel\,
  M. Guttmann\, B. S. Richards\, H. Hölscher\, G. Gomard\, E. Klampaftis\,
  M. Kavalenka\, Self-Cleaning Disordered Microcavity Array for Photovoltai
 c Modules\, ACS Appl. Mater. Interfaces 10\, 2929 (2018)\n\n[3] 	R. H. Sid
 dique\, Y. J. Donie\, G. Gomard\, S. Yalamanchili\, T. Merdzhanova\, U. Le
 mmer\, H. Hölscher\, Bio-inspired Phase Separated Disordered Nanoholes fo
 r Thin Photovoltaic Absorbers\, Sci. Adv. 3\, e1700232 (2017)\n\n[4]	J. Sy
 urik\, R. H. Siddique\, A. Dollmann\, G. Gomard\, M. Schneider\, M. Worgul
 l\, G. Wiegand\, H. Hölscher. Bio-inspired\, large scale\, highly scatter
 ing films for nanoparticle-alternative white surfaces\, Sci. Rep. 7\, 4663
 7 (2017).\n\n[5]	J. Syurik\, G. Jacucci\, O. D. Onelli\, H. Hölscher\, S.
  Vignolini. Bio-inspired Highly Scattering Networks via Polymer Phase Sepa
 ration\, Adv. Funct. Mater. 28\, 1706901 (2018).\n
LOCATION:PfizerLecture Theatre\,  Department of Chemistry\, Lensfield Road
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