Silk or Polyester? How Optics Can Help Determine an Answer
Miaochan Zhi
I love silk. Many clothes in my wardrobe are made of 100% silk. This is an extension of my love of all things natural. Also, it is due to the fact that I lived in Hangzhou, China which is very famous for silk.
So is this silk or polyester? It can be hard to tell. Image from http://en.wikipedia.org/wiki/Silk.
Last year, a report that caught my attention pointed to biological applications of silk, which provides the scientific support of using silk material. At the 2012 Frontier In Optics meeting, invited speaker Fiorenzo Omenett talked about silk-based optics and photonics, which made news everywhere, such as here: Silk’s Photonic Talents Brought to Light at FiO 2012. Recently, his group discovered that silk is an excellent material for guiding light thus can find applications in biosensor. Silk is very eco-friendly as it is biocompatible, biodegradable, and produced naturally by spiders and silkworms, a renewable resource. Details can be found about his talk: Silk---the ancient material of the future which I also inserted below.
Video from Youtube.
As a natural material lover, I resist use of synthetic materials such as polyester and nylon. But sometimes, it is hard to tell them apart. You can tell by burning the material but that will destroy it.
Now it might be possible to tell them apart non-invasively by using nonlinear spectroscopy. In a paper (Non-invasive determination of the complete elastic moduli of spider silks) published yesterday in Nature materials, scientists at Arizona State University spatially map the elastic stiffnesses on a spider web without deforming or disrupting the web using a non-invasive nonlinear laser spectroscopy - Brillouin light scattering. It is featured in yesterday’s physics.org news: Researchers unravel mysteries of spider silk.
This study will have applications in the area of bio-inspired materials, such as precise materials engineering of synthetic fibers to create stronger, stretchier, and more elastic materials.
If you are further interested in this, please check out the biological application of nonlinear optics talks in the upcoming 2013 Nonlinear Optics meeting.
