tailieunhanh - Mesoscopic Model for Mechanical Characterization of Biological Protein Materials

Unfortunately, soon after these first attempts, the designer will find the robot getting stuck on what seem to be innocuous objects or bumps, held captive under a chair or fallen tree trunk, incapable of doing any- thing useful, or with a manipulator that crushes every beer can it tries to pick up. Knowledge of the mechanics of sensors, manipulators, and the concept of mobility will help reduce these problems. This book provides that knowledge with the aid of hundreds of sketches showing drive lay- outs and manipulator geometries and their work envelope. It discusses what mobility really is and how to increase it without increasing the size of the. | Mesoscopic Model for Mechanical Characterization of Biological Protein Materials Gwonchan Yoon1 Hyeong-Jin Park1 Sungsoo Na1 and Kilho Eom2 t 1 Department of Mechanical Engineering Korea Umversily Seoul 136-701 Republic of Korea zNano-Bio Research Center Korea Institute of Science Technology KIST Seoul 136-791 Republic of Korea t Corresponding Author. E-mail nass@ Corresponding Author. E-mail eomkh@ 1 Abstract Mechanical characterization of protein molecules has played a role on gaining insight into the biological functions of proteins since some proteins perform the mechanical function. Here we present the mesoscopic model of biological protein materials composed of protein crystals prescribed by Go potential for characterization of elastic behavior of protein materials. Specifically we consider the representative volume element RVE containing the protein crystals represented by Ca atoms prescribed by Go potential with application of constant normal strain to RVE. The stress-strain relationship computed from virial stress theory provides the nonlinear elastic behavior of protein materials and their mechanical properties such as Young s modulus quantitatively and or qualitatively comparable to mechanical properties of biological protein materials obtained from experiments and or atomistic simulations. Further we discuss the role of native topology on the mechanical properties of protein crystals. It is shown that parallel strands hydrogen bonds in parallel enhance the mechanical resilience of protein materials. Keywords Mechanical Property Protein Crystal Go Model Virial Stress Young s Modulus 2 INTRODUCTION Several proteins bear the remarkable mechanical properties such as super-elasticity high yield-strength and high fracture Such remarkable properties of some proteins have attributed to the mechanical functions. For instance spider silk proteins exhibit the super-elasticity relevant to spider-silk s 5 Specifically .