An interdisciplinary collaboration among scientists from DTU Mechanical Engineering and University of Oxford is currently examining the possibility of using the mechanical properties of the Nephila spiders web for developing lighter building constructions. Torben Lenau from DTU Mechanical Engineering and Thomas Hesselberg are developing the idea.
Thomas Hesselberg is a biologist and from University of Oxford where he is a member of ”The Oxford Silk Group”, a group of researchers who are examining the different properties of silk. He is researching in the mechanical aspects of the Nephila spiders web, a spider web that is known for being so strong that it can slow down the flight of a small bird completely. The Nephila spider, which is also known as the Golden Orb Weaver because of the golden color of the web, is a spider species from the tropics whose web is constructed in a way that makes it particularly strong.
A spider web with unique mechanical properties
Spider webs are constructions in nature which are able to handle extraordinary impacts. When the Nephila spider web is that strong, it is because the construction is reinforced by the non-sticky spiral, a “helping” construction usually removed by other spiders. Keeping the non-sticky spiral of course has some disadvantages such as “holes” in the web where there is no sticky spiral to catch the prey and the fact that the non-sticky spiral impedes the signal function of the radii. The advantages of the non-sticky spiral are the increased, mechanical support of the entire web and that the web generally becomes more resistant to the influence of wind.
Thomas Hesselberg has tested the mechanical properties of the Nephila spider web in a wind tunnel at a wind speed of up to 7.7 meters per second. As a control, the non-sticky spiral was removed and in this way it was demonstrated that it has a supportive effect on the web. Thomas Hesselberg also uses numerical modeling, where the results are supporting the mechanical test.
It is the non-sticky spiral that has a particularly
supporting effect on the entire web.
Here the non-sticky spiral is yellow, the sticky spiral
is blue and the supporting frame is red.
From spider webs to buildings
These properties which are now uncovered by Thomas Hesselberg research in the the Nephila spiders web, have put Torben Lenau from Engineering Design and Product Development at DTU Mechanical Engineering on the track of new possible solutions regarding building constructions. Whereas Thomas Hesselbergs research is basic research in biology, Thomas Lenau is focused on how to use the phenomena of nature as a concrete solution of problems in the development and design of new products, or as a solution to existing problems.
To begin with, Torben Lenau examined the market in relation to products, where you might benefit from transferring the excellent mechanical qualities of the Nephila spiders web to other cases. Ideas such as improving nets or the concert tents of the Roskilde Festival where quickly discarded, the first because it is at small industrial area, the second because the concert tents already are well functioning lightweight constructions.
But then it emerged that there a need for improving building constructions and now Torben Lenau is cooperating with a company about the design and development of a new kind of skylights using the mechanical properties of the Nephila spider web demonstrated by Thomas Hesselbergs research.
Several researchers at DTU Mechanical Engineering are working at biomimetical projects where they try to solve design problems by studying the solutions of nature, for example Seunghwan Lee at Materials and Surface Engineering.
Torben Lenau og Thomas Hesselberg have recently published the
article ”Biomimetic Self-Organization and Self-Healing” in
Engineered Biomimicry.
The Nephila spider is also called the Golden Orb Weaver because of
the golden color of the web. Photo by Bronwyn Silver, read her blog
about Walmer South Conservation Reserve here.