Using Spider Silk as a Chemical Detector

EPFL fiber optics specialists have discovered very promising and unique qualities of spider silk when it comes to conducting light and reacting to certain substances. Spider silk strands are perfectly cylindrical, smooth, transparent, and extremely solid - some of the same characteristics as glass-based fibers. But while glass is inert, spider silk is made up of very long proteins rolled into a helix structure whose bonds are sensitive to a number of chemical substances. The EPFL researchers are working on natural silk strands with a diameter of 5 microns. The researchers stretch a silk strand taut in a tiny bracket and direct a laser beam at one end of the strand. At the other end, a polarization analyzer is used to measure infinitesimal changes in the light passing through it. If a gas that interacts with the silk strand is present, the device will pick up on this immediately.

Transcript

00:00:04 in this lab at epfl we are making research on optical fiber and we are using this optical fiber as a sensor so it's like an optical nerve that can collect information along the optical fiber here we are carrying out a research not using glass fiber like use for telecommunications but spider drag lines spider silk are intrinsically sensitive

00:00:30 to chemical substances because they are made of proteins with bonds that are broken by the presence of some chemical substance like ammonia like acetic acid and water vapor and this is totally reversible the protein returns to its original state in absence of the substance so what we do is very simple we take a laser beam we launch it through the spider silk the light

00:00:57 propagates through the spider silk and at the output of this sample of silk fiber by analyzing the prion property of the light we can retrieve the information on the chemical substance we are a very early stage of This research but the the results are extremely promising so we expect that we open a new area in fiber optics with this new material enely new material with

00:01:23 entirely new properties oh