Testing Strength of Spider Silk

Testing Strength of Spider Silk
A Naphila Clavipe spider is held by mechanical engineering student David Chavezticas.
ME students are testing the strength of
silk from Naphila Clavipe spiders.

Spider silk is a fascinating material. It may break at the slightest tug because of its thinness, but it is in fact quite strong. Per unit mass, spider silk's tensile strength has even been compared with the force of steel.

Vilupanur Ravi, professor of chemical & materials engineering, is leading a study to measure the mechanical properties of the delicate material, with an interdisciplinary team of students.

Unlocking the mysteries of spider silk could perhaps one day lead materials engineers to apply such properties to develop stronger light-weight materials, like those used to make bulletproof vests, he says.

Acquiring significant amounts of spider silk is challenging, so Ravi and his students have developed a small mechanical apparatus that gently holds down the spider's legs while the silk is gingerly collected by a rotating cylinder. Students keep the Naphila Clavipe spiders as happy as possible by hand-feeding them in the process.

Students are also developing an apparatus that would allow them to measure the silk's tensile strength. With a minimal budget, students must be inventive.

“It's a great way for students to exercise their engineering skills because they have to think creatively,” Ravi says. “They have to develop a low-cost mechanism to gather data. It's a great educational experience.”

**This story originally ran in the Fall 2007/Winter 2008 issue of PolyTrends Magazine. To see the story in its original layout and read other interesting stories about Cal Poly Pomona and alumni, check out PolyTrends online.**