Variable stiffness device and method of varying stiffness

A method of varying stiffness of a variable stiffness device,

• the variable stiffness device comprising:
• a first elongated member having a hollow shape and extending along a longitudinal axis;
• and
• a second elongated member including a plurality of heaters, the second elongated member being disposed inside an inner circumference of the first elongated member, and extending in parallel to the first elongated member along the longitudinal axis,
• the first elongated member including one or more high bending stiffness portions and a plurality of low bending stiffness portions, the one or more high bending stiffness portions and the plurality of low bending stiffness portions being alternately aligned along the longitudinal axis,
• one of the first elongated member and the second elongated member including a shape-memory pipe, and
• each of the plurality of heaters being spaced apart in an inner space of the shape-memory pipe such that a longitudinal position of each of the plurality of heaters corresponds with a longitudinal position of a low bending stiffness portion of the plurality of low bending stiffness portions, respectively,
• the method comprising:
• heating, by the plurality of heaters, portions of the shape-memory pipe corresponding to the plurality of low bending stiffness portions to increase bending stiffness of the shape-memory pipe;
• and
• lowering a temperature of the portions of the shape-memory pipe corresponding to the plurality of low bending stiffness portions to decrease the bending stiffness of the shape-memory pipe.