Design and Development of a Multi-Functional Bioinspired Soft Robotic Actuator via Additive Manufacturing

Abstract

The industrial revolution 4.0 has led to a burst in the development of robotic automation and platforms to increase productivity in the industrial and health domains. Hence, there is a necessity for the design and production of smart and multi-functional tools, which combine several cutting-edge technologies, including additive manufacturing and smart control systems. In the current article, a novel multi-functional biomimetic soft actuator with a pneumatic motion system was designed and fabricated by combining different additive manufacturing techniques. The developed actuator was bioinspired by the natural kinematics, namely the motion mechanism of worms, and was designed to imitate the movement of a human finger. Furthermore, due to its modular design and the ability to adapt the actuator’s external covers depending on the requested task, this actuator is suitable for a wide range of applications, from soft (i.e., fruit grasping) or industrial grippers to medical exoskeletons for patients with mobility difficulties and neurological disorders. In detail, the motion system operates with two pneumatic chambers bonded to each other and fabricated from silicone rubber compounds molded with additively manufactured dies made of polymers. Moreover, the pneumatic system offers multiple-degrees-of-freedom motion and it is capable of bending in the range of −180° to 180°. The overall pneumatic system is protected by external covers made of 3D printed components whose material could be changed from rigid polymer for industrial applications to thermoplastic elastomer for complete soft robotic applications. In addition, these 3D printed parts control the angular range of the actuator in order to avoid the reaching of extreme configurations. Finally, the bio-robotic actuator is electronically controlled by PID controllers and its real-time position is monitored by a one-axis soft flex sensor which is embedded in the actuator’s configuration.

Control Methodologies for Robotic Grippers: A Review

“…PIDs were also used for soft gripper control. Recent applications are seen in [30][31][32]. In [30] a PID position control for pneumatic soft actuators was developed.…”

“…Recent applications are seen in [30][31][32]. In [30] a PID position control for pneumatic soft actuators was developed. A three-fingered soft gripper was constructed using as many soft actuators, resulting in a device capable of delicate grasping.…”

Overview of 3D Printed Exoskeleton Materials and Opportunities for Their AI-Based Optimization

“…Developed, e.g., a multifunctional biomimetic soft actuator with a pneumatic movement system imitating the movement of a human finger with bending from −180 • to 180 • (but without reaching extremes). The proportional-integral-derivative controller allows for monitoring the position of the exoskeleton in real time by a single-axis soft deflection sensor built into the actuator [42].…”

Design, Assembly and Control of a Differential/Omnidirectional Mobile Robot through Additive Manufacturing

“…To our knowledge, this prototype has yet to be addressed in the literature. It is worth mentioning that a similar approach to the one presented in this article is the one developed by Kladovasilakis et al [33], where a bio-robotic actuator, which imitates the movement of a human finger, was designed and manufactured with the characteristic that the material could be changed from rigid polymer for industrial applications to thermoplastic elastomer for complete soft robotic applications.…”