Active bending device arranging SMA wires to prevent surface overheating

Abstract

A tool to control the bending of a laser fiber protruding from the endoscope tip using shape memory alloy(SMA) wire that shrinks when heated by Joule heat was developed. In the conventional bending device, the SMA wire that is driven during bending contacts the outer tube that covers the device and overheats the surface of the device. For the prevention of surface overheating, a link part was added to the center of the device that restricts the movement of the driven SMA wires. The bending device with a center link was fabricated and measured the bending angle and surface temperature. The device with a center link realized a larger bending angle and lower surface temperature comparing the conventional structure.