Rubber Elasticity of Genes
Over 200 years ago, rubber emerged as an extremely important biomaterial due to its unique soft, elastic mechanical behavior. Driven by technological interest, the bizarre thermomechanical behavior of rubber was discovered in 1805: it heats up when stretched, and cools when relaxed. This phenomenon was not fully understood for over a century. It is now understood to be a consequence of the 2nd law of thermodynamics, and the elasticity of rubber’s constituent molecules: enormous, stringy molecules termed polymers. Recently, our understanding in this area has been broadened by modern, ultrasensitive experimental tools that permit high-resolution measurement of the elasticity of single polymers. A major focus of this recent work has been the elasticity of DNA, known popularly as the genetic material, but itself also a polymer. Omar Saleh will discuss how the current experiments work, explain why DNA has become a popular tool for polymer science, and discuss what recent results tell us about this very old problem.
Omar Saleh is Professor at the Materials Department of the University of California in Santa Barbara and currently Visiting Fellow at CAS.