Objective: In this work we design and evaluate a bidirectional pneumatic soft actuator made from silicone rubber (RTV2 C10) for the use in prosthetic hand. The actuator aimed to enhance flexibility and provide motion in two directions that mimic the actions of the human fingers. Materials and Methods: Two parallel air chambers are used in the actuator design where each chamber is divided into smaller internal cavities. These chambers are linked through a narrow connecting channel. The fabrication process relied on a molding technique based on 3D printed molds. Three separate mold components were designed and printed to allow accurate casting of silicone rubber into the desired shape. The completed actuators were then tested using an experimental setup. Results: We evaluate the performance of the developed actuators by measuring the maximum bending angle and output force under various air pressures. Three air-chamber dimensions (3.5 mm, 4.5 mm, and 5.5 mm) were tested to compare the actuator’s response. We noticed that the 5.5 mm chamber produced the largest bending angle whereas the 3.5 mm chamber showed the smallest. On the other hand, force analysis revealed that the actuator with 3.5 mm spacing generated the highest output force at an air pressure of 102 kPa and the 5.5 mm model returned the lowest under the same conditions. Discussion: The findings suggest that increasing the distance between air chambers enhances bending and overall flexibility where it indicates that shorter chamber spacing raises greater force. Conclusion: The developed actuator demonstrates promising properties for use in prosthetic hand designs. The bending range and force output enable the actuator for producing human-like finger motion that used in assistive robotic applications.
