Creativity with Spiders - Silk Part I
Spiders are found all over the world (to my delight and to the dismay of others). Their sizes range from the Samoan moss spider (Patu marplesi, body length 0.3 mm) to the Goliath birdeater (Theraphosa blondi, body length 11.9 cm). And to put to rest the misconception that not all spiders are poisonous - all spiders have venom glands, and thus they are all venomous (and no, the most venomous one is NOT the daddy long-legs, or harvestmen, though they are good predators).
Spiders are extraordinary organisms, and they are most known for their eight legs and their production of silk. Unlike insects, spiders produce silk in their abdomens with a highly choreographed liquid chemical mixing that only become solid in the presence of air. The type of chemicals and the sequence of mixing combined with ion channels create a variety of silk, up to seven different types actually, that have equally diverse functions from anchoring to sticky webbing to constructing the egg sacs (see last week's post on how the egg sac webbing is using in the traditional gyil).
The silk produced by the golden orb weavers (genus Nephila) shines like gold in the
sunlight (hence the name). The chemicals that make up the silk provide heightened catch rates in both sunlight and shade - the yellow color is an attractant to day-time flying pollinating insects and will blend in with the vegetating in darker areas. In nature, many of these orb-weaving species construct very impressive webs, consisting of multiple trips around the web laying down a matrix of sticky and non-sticky silk. While these spiders may reach two inches in body length, their webs can be one meter in diameter like those constructed by N. clavipes.
In 2004, Simon Peers and Nicholas Godley completed the first large textile piece made completely from natural spider silk. It took them three years and 1.2 million Golden silk orb-weavers collected in Madagascar to create a shawl. They completed a larger cap using the same methods in 2012. Below is a video demonstrating the process of extracting the silk.
While this particular textile is the first of it's kind, it requires the understandably reluctant assistance of over a million spiders that had to be taken from their webs (they were later released after 30 minutes). The lightweight structure and durability of spider silk has been appealing for engineers over the past few years, trying to replicate the chemical composition and behavior of the silk. One of my favorite books about the subject, Spider Silk: Evolution and 400 Million Years of Spinning, Waiting, Snagging, and Mating, written by Leslie Brunetta and Catherine L. Craig, presents the multiple ways spiders have evolved and how humans are trying to imitate the silk production product.
The northern Japanese company, Spibar, has started the production of synthetic spider silk, and completed the first dress spun by this synthetic material. Like natural silk, the fiber produced called Qmonos (Japanese for spider web) is lightweight, breathable, flexible. This production was made for display, not for durability, but the company has high hopes for focusing on this next step in imitating nature using human material engineering. Maybe one day humans will be able to produce a material that acts and functions like a natural material, but honestly nature will always do it best.