[ASME ASME 2006 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference - Philadelphia, Pennsylvania, USA (September 10–13, 2006)] Volume 2: 30th Annual Mechanisms and Robotics Conference, Parts A and B - Mechanics of the Whole Skin Locomotion Mechanism Concentric Solid Tube Model: The Effects of Geometry and Friction on the Efficiency and Force Transmission Characteristics