DESIGN, FABRICATION, AND CHARACTERISTICS EVALUATION OF PNEUMATIC NETWORK SOFT ACTUATOR FOR SOFT ROBOTICS IN MEDICAL REHABILITATION

• Main Author: Mega Putri, Syam
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/65222
• Institution: Institut Teknologi Bandung

The hand rehabilitation process takes a long time and is very dependent on the therapist. Although rigid robotics rehabilitation technology that has been developed can speed up the rehabilitation process, there are still chances in developing better system for hand rehabilitation. Therefore, soft robotics rehabilitation technology was developed by utilizing soft actuators as the drivers. Soft actuators come in various forms, ranging from McKibben air muscle, fiber-reinforced actuators, and pneumatic network actuators (PneuNet). The design that can be used to assist flexion (grasping) movement exercises with less complex fabrication method is the PneuNet form. Therefore, in this research, the design, fabrication, and characteristic evaluation were carried out for PneuNet-type soft actuators. The fabrication method chosen is 3d printing for its ability in producing customable devices based on the user’s needs. The 3d printing method consists of three stages, the 3-dimensional modelling, slicing, and fabrication using a 3d printer. In this study, the 3d printing process was carried out repeatedly by changing the parameters in the slicer software to obtain an actuator that was resistant to leakage. From the results of the study, it was concluded that the actuator should be printed vertically with a minimum wall thickness of 4 times that of the extruder output. Therefore, the extrusion width and layer height values must match the actuator thickness. In addition, the appropriate thin wall behavior is perimeters only and allow gap fill. After fabrication, characteristic evaluation were carried out to observe the deformation of input pressure and the dynamic response of the actuator. The actuator angle data was evaluated using the principle of optical motion capture (mocap). On the actuator, markers are placed at both ends and the middle of the actuator. The actuator movement is captured by the camera in the form of images and videos. Image processing aims to get the marker position and calculate the bending angle of the actuator. Meanwhile, video processing with optical flow analysis is carried out to observe the magnitude and direction of the actuator speed. The evaluation shows that the bending angle of the actuator is able to exceed the angle of the index finger during flexion, which is 110o. The most flexible actuator is the perimeters only actuator with a thickness of 1.4 mm. Meanwhile, the stiffest actuator is the perimeters only actuator with a thickness of 1.6 mm. The dynamic characteristics of the actuators are identified as second-order and overdamped systems.