A control mechanism for rotating an instrument tip 204 of a surgical scoping device comprising an actuator 216 and an energy delivery structure. The actuator 216 is formed from a shape memory effect material. The energy delivery structure is connected to the actuator 216 delivering energy to cause a change in temperature of the shape effect material. The actuator 216 exhibits a torque in response to the shape memory effect material reaching a threshold temperature. The shape memory effect material has a helical or a pair of helical structures and is configured to unwind. The energy delivery structure has a conductive element and a heater thermally connected to the actuator. The control mechanism has a coolant delivery structure. An electrosurgical instrument 200 for applying radiofrequency electromagnetic energy and microwave EM energy to biological tissue is also provided.
