Spider silk can create lenses useful for biological imaging

Date:
June 30, 2020
Source:
American Institute of Physics
Summary:
Spider silk is useful for a variety of biomedical applications:
It exhibits mechanical properties superior to synthetic fibers
for tissue engineering, and it is not toxic or harmful to
living cells. One unexpected application for spider silk is
its use in the creation of biocompatible lenses for biological
imaging applications. Researchers now describe the feasibility of
creating lenses capitalizing on the properties of natural spider
silk material.



FULL STORY ========================================================================== Spiders -- what are they good for? The answer, it turns out, is more
than just insect control.


========================================================================== Spider silk is useful for a variety of biomedical applications. It
exhibits mechanical properties superior to synthetic fibers for tissue engineering, and it is not toxic or harmful to living cells.

One unexpected application for spider silk is its use in the creation
of biocompatible lenses for biological imaging applications. A team of researchers from Tamkang University and National Yang-Ming University
in Taiwan describes the feasibility of creating lenses capitalizing on
the properties of natural spider silk material in the Journal of Applied Physics, from AIP Publishing.

A spider can spin several different types of silks, each with different properties and functions. To create the spokes of their web, spiders
use a type of silk known as dragline silk.

"Dragline silk is an interesting natural material because of its
significant features, such as high elasticity, great toughness and large tensile strength," said Cheng-Yang Liu, one of the authors on the study
and a professor at National Yang-Ming University. Compared to its weight,
the strength of dragline silk is greater than steel.

The authors collected smooth, uniform dragline silk from Pholcus
phalangioides spiders, commonly known as daddy longlegs, and dripped
a resin onto the silk fiber. As the resin condensed on the fiber, the
wetting properties of the silk naturally formed it into a dome shape,
which they found could be used as an optical lens. The mechanical and
optical properties of the silk also make it ideal for supporting the lens.

When they shined a laser onto the lens, it generated a high-quality
photonic nanojet -- a type of beam that can provide large-area, super-resolution imaging for biomedical applications. By tuning the length
of time the silk spends under the resin drip, the size of the dome lens
can be changed, allowing the photonic nanojets to be optimized for the
desired type of imaging.

"The dome lens with flexible photonic nanojets is suitable for imaging
the nanoscale objectives in different depths within biological tissue,"
Liu said.

After additional testing, the researchers hope this type of spider
silk-based lens can be used to deliver light for biological imaging
and operation.


========================================================================== Story Source: Materials provided by American_Institute_of_Physics. Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. C. B. Lin, Yi-Ting Lee, Cheng-Yang Liu. Optimal photonic nanojet
beam
shaping by mesoscale dielectric dome lens. Journal of Applied
Physics, 2020; 127 (24): 243110 DOI: 10.1063/5.0007611 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/06/200630111453.htm

--- up 23 weeks, 2 hours, 39 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)