Figure 2.

Characterization of the variable stiffness SMP composite. a) Variable stiffness catheter without filler showing the embedded control structure. The copper wire was uniformly coiled around the inner lumen over the entire length of the VS segment. b) SEM image of the catheter surface with embedded graphite and c) NdFeB particles. d) Glass transition temperature (T _g) versus concentration of NdFeB and graphite. e) Thermal conductivity of NdFeB and graphite in a polymeric matrix. f) Electrical conductivity of NdFeB and graphite in a polymeric matrix. Stiffness ratio and complex modulus values in the rubbery and glassy state versus g) increasing concentration of graphite and h) NdFeB. i) Hysteresis curves of NdFeB in a polymeric matrix.