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<p><font color="#990000"><u><b style="mso-bidi-font-weight:normal"><span
style="font-size:14.0pt;font-family:"Times New
Roman",serif; mso-fareast-font-family:"Times New
Roman";mso-ansi-language:EN-US;mso-fareast-language:
ES;mso-bidi-language:AR-SA" lang="EN-US">Biological
Plywoods: Lessons from Nature's Fibrous Composites</span></b></u><u><br>
</u></font><br>
Lugar y fecha: Aula Magna, miércoles 10 de mayo a las 11:00 hs<br>
<br>
Disertante: <b>Alejandro Rey</b><br>
El profesor <span lang="ES-AR">Alejandro Rey, originario de
Argentina, es profesor en la Universidad McGill desde 1988, y
director del Grupo de Investigación en Modelado de Materiales
perteneciente al Departamento de ingeniería Química de dicha
universidad. </span><span lang="ES-AR"><span lang="ES-AR">Ha
dictado cursos en nuestra institución como profesor visitante
en dos ocasiones </span></span><span lang="ES-AR"><span
lang="ES-AR"><span lang="ES-AR">en el marco del subsidio
Milstein del programa raíces,</span> y a</span>ctualmente se
encuentra visitando nuestra institución por tercera vez en el
marco el subsidio Milstein y del programa DOCTORAR.<br>
</span><span lang="ES-AR"></span><br>
<u>Resumen:</u><br>
This seminar presents recent theory and simulation results on the
structure, self-assembly, and functionality of biological plywood
materials [1,2], an ubiquitous material organization found
throughout Nature, including plant cell walls, exocuticles of
insects, bone, and cornea. The key points of the talk are to
demonstrate the principles used by Nature to develop stiff,
strong, tough, multifunctional materials from simple rod-like
filaments and to show a few examples based on biomimetic
engineering on how to use the plywood architecture in optical and
sensor devices.<br>
The talk first describes how directed chiral self-assembly creates
3D fiber architectures with well defined pitches, a structural
feature behind most of the structure-property relations. The
presence of chiral fiber ordering is detected by the presence of
"arc patterns" which is ubiquitous also in man-made macroscopic
plywoods, but to extract precise fiber ordering requires geometric
modeling. Here we show applications of the technique to a Costa
Rican's beetle and to green algae. Finally we study the
nano-wrinkling in surface layers of biological plywoods, which are
responsible for optical functionalities and explain the
diffraction patterns and color changes in tulip-like materials. A
model for a bio-inspired color-based water sensor concludes the
talk.<br>
<br>
<font size="-1">1. A.D. Rey, "Liquid Crystal Models of Biological
Materials and Processes”, Soft Matter, 6-5, 3402-3429, 2010.<br>
2.
<a class="moz-txt-link-freetext"
href="https://publishing.aip.org/publishing/journal-highlights/understanding-natures-most-striking-colors">https://publishing.aip.org/publishing/journal-highlights/understanding-natures-most-striking-colors</a></font><br>
</p>
<br>
<pre class="moz-signature" cols="72">--
Dr. Ezequiel R. Soulé
División Polímeros Nanoestructurados - INTEMA
Facultad de Ingeniería, UNMdP
Av. Juan B. Justo 4302 - (7600) Mar del Plata,
Buenos Aires, Argentina
TE: (54-223) 481-6600 int 240</pre>
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