Physics & Astronomy Colloquium – Dr. Jeffery Yarger
About the event
The Department of Physics and Astronomy invites all to a colloquium featuring Dr. Jeffery Yarger, School of Molecular Sciences, Arizona State University. Dr. Yarger will present his talk, “Silk Biomimicry: Elucidation of Structure-Function Relationships in Protein-Based BioPolymers.”
Meet for refreshments before the lecture at 3:45 – 4:10 p.m. in the foyer on floor G above the lecture hall.
The polymer industry has often used silk as an example of a natural material with properties that would be advantageous to mimic in synthetic textiles. In fact, one of the most used synthesis polymers, nylon, was inspired by silk. However, despite decades of research into synthetic polymers, natural fibres are often still preferred. In particular, silk is favoured because of its unique combination of strength and texture. When someone says ‘silk’, they are typically referring to cocoon silks, and more specifically the silk made by the silk moth Bombyx mori. Silk moths were domesticated over 5,000 years ago, and their silk comes from the formation of cocoons during the larval stage. Several insects and all spiders produce silk, but only the silk of moth caterpillars has been extensively used for textile manufacturing. Although the culture and use of other types of silk has had very limited success so far, there is huge interest in this field, motivated by the broad spectrum of materials properties of insect silks.
The ‘Yarger Lab’ is interested in uncovering the structure-function relationship in silk, with a goal of mimicking the diverse molecule physical and mechanical properties to create a broad range of reverse engineered protein-based biopolymers inspired by nature.
Spiders are masters when it comes to making silk: a typical orb-weaving spider produces at least seven different silks, each synthesized and spun by silk glands and spinnerets located on its abdomen. The structure and function of the most common spider silks have been characterized to varying extents. Spider dragline silk is typically a combination of two types of silk, major ampullate and minor ampullate silk.
Spider Dragline Silk fibres are typically 1–5 micron in diameter and challenging to see with the naked eye. However, when these fibres are analysed with high-resolution microscopy techniques, such as scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the fibres are easily distinguished, and micro- and nanometre morphologies can be studied, as shown progressively toward the right-side panels of the figure above. Professor Yarger and his research team explore new methods at characterizing the molecular structure and function of silk, with the ultimate goal being ‘Silk Biomimicry’.