Outer shell actuator driving central bending shaft by balloon arrays circumferentially-arranged inside of shell

This paper proposes a novel outer shell actuator having circumferentially-arranged micro balloon arrays on an inner wall of the shell. The actuator can drive central bending shaft through the cylindrical shell by swelling pneumatic balloon arrays. Surrounding balloons push the central shaft independently. It is possible to manipulate a head of the shaft by controlling individual deformation of surrounding balloons. The outer shell actuator is designed and developed in order to manipulate a medical forceps for endoscopic surgery as a practical example of the central shaft. Manipulating of forceps requires manipulating whole endoscope, which causes undesired motion of other medical tools for the endoscope such as a camera. Presented outer shell actuator allows independent manipulation of forceps.