Steerable Robotic Needles with Tunable Stiffness Segments for Large Curvature Maneuvers

A steerable robotic needle formed from a compliant wire that is surrounded by an inner layer having one or more tunable regions positioned in predetermined locations and an inert region extending over the rest of the wire. The tunable region changes stiffness in response to an external trigger, such as heating via electrical energy, so that the needle can bend more readily in the predetermined location. The inner layer may be encapsulated in an elastomeric tube to prevent heat from reaching the surrounding environment. The resulting change in stiffness allows the needle to perform maneuvers in a body that require a larger curvature.