Abstract: Flexible elongate device comprising a flexible elongate member having proximal and distal extremities and a tool actuator member mounted on the distal extremity of the flexible elongate member. An elongate element having a negative coefficient of expansion is carried by the distal extremity of the flexible elongate member and is connected to the tool actuator member for causing movement of the tool actuating member. A control console is provided for supplying electrical energy to the elongate element.