Abstract: Enhanced Adhesives Inspired by Spider Silk

Spider silk fiber is a biopolymer that is made in nature completely sustainably at a low energy, ambient temperature, and is perfectly biodegradable. The silk has one-third of the tensile strength of steel; but is one-sixth of the density. More research needs to be done investigating this material because it is a high-performance polymer that out performs every similar material we have available today. We are specifically interested in the silk from the recluse spider, Loxosceles, because in addition to its strength, it has outstanding adhesive capabilities that arise from its unique morphology.

Most silks are cylindrical, but Loxosceles silk is a flat ribbon that the spider assembles into a system of loops. I will investigate the loop junction geometries and how they give rise to the 400 MPa loop opening stress. I will use Scanning Electron Microscopy to obtain images of loop junctions and use that data to measure the contact area of the self-adhered silk. This will allow me to calculate the surface energy of the silk and give insight to the mechanism behind the adhesion. Van der Waals forces affect the adhesion, but this close study of the contact sites will give light to what other bonding is involved with the adhesion (e.g. electrostatic forces, hydrogen bonding).