This paper presents the design and implementation of a lightweight and powerful fingers actuator capable of grasping various shaped objects. The proposed fingers actuator is designed on the underactuated structure formed by a thumb and an index finger, which are composed of a zigzag tube with one chamber and a soft polyurethane foam with notch. When the inside of the tube is pressurized by pneumatics, each finger joint can be bent simultaneously performing one degree of freedom motion. Due to the compliance of pneumatic and the softness of the structure, it can automatically hold various types of objects. The design parameter of each joint is illustrated in order to base on distributed grasping force evenly against the objects. The developed fingers could not only perform wide range of grasping but also realize two and half times larger force/weight ratio than general fingers actuator with electric servo motor. Lastly, as the application of the proposed fingers, it is mounted on an aerial manipulator for the door opening mission, and its validity is experimentally verified.

This paper presents an aerial robot with a manipulator to implement door opening mission. Although general aerial robots have advantages of flying in the three-dimensional space freely, they don't have any capability of moving to another room when the door is closed. To overcome this problem, we propose a new configuration of an aerial manipulator with perching function, knob-twisting function, and door-pushing function. Perching function can be achieved by integration of door-approach control, the mechanism for perching and attitude-change control. With regard to knob-twisting function, the design concept of a light-weight manipulator generating large enough force to twist the knob is introduced, which is composed of a soft-bag actuator with variable restriction to perform the arbitrary curved trajectory. On the other hand, the door pushing force is aimed to be generated by the lift of the propeller, which is helpful to avoid gaining the additional weight. The validity of the proposed methods is experimentally verified by using the developed prototype.