Search

Soft robotics is projected to have a significant impact on healthcare, industry, and the military to deliver assistance in rehabilitation, daily living activities, repetitive motion tasks, and human performance augmentation. Many attempts have been made for application-specific robotic joints, robots, and exoskeletons using various actuator types, materials, and designs. The progress of creating soft robotic systems can be accelerated if a set of actuators with defined characteristics were developed, similar to conventional robotic actuators, which can be assembled to create desired systems including exoskeletons and end effectors. This work presents the design methodology of such a modular actuator, created with a novel corrugated diaphragm that can apply linear displacement, angular displacement, and force. This modular actuator approach allows for creating various robotic joints by arranging them into different configurations. The modular corrugated diaphragm actuator concept was validated through numerical simulation, fabrication, and testing. Linear displacement, angular displacement, and force characteristics were shown for a single module and in multi-module assemblies. Actuator assemblies that are configured in a serial and parallel manner were investigated to demonstrate the applicability and versatility of the concept of the modular corrugated diaphragm actuator for creating single and multi-degree-of-freedom joints. [ABSTRACT FROM AUTHOR]

Recently, soft materials such as silicone elastomers are widely used in soft robotics due to their high flexibility and safe physical interaction with humans. Focusing on three aspects— highly elastic materials, sacrificial materials, and actuation units , we aim to develop an additive manufacturing strategy that allows the fabrication of highly elastic soft structures more efficiently. First, silicone thinner is used to tailor the mechanical properties of the soft silicone elastomer. We found out that adding 20% volume thinner to the silicone improved the ultimate tensile elongation of 3D printed silicone samples upto 1260%, which is the highest among all the 3D printed soft materials previously reported. However, in a cyclic tensile test, this strain is not achieved; instead, the maximum strain was 600%. Second, carbohydrate glasses are introduced as sacrificial materials for 3D printing silicone with hollow channels. Few configurations of pneumatic and hydraulic actuators are developed by forming channels in the silicone elastomer via 3D printed sacrificial carbohydrate structures and subsequently dissolving. The 3D printed structures actuated successfully to get morphed shapes, which showed that our method is effective for manufacturing of functional soft robotic structures. Unlabelled Image • Material processing parameters for additive manufacturing process of very soft structures are presented. • 3D printing silicone samples with 20% thinner resulted in an ultimate tensile elongation of 1260% • Extensive material characterization results for the 3D printed soft materials are presented. • Soft actuators are fabricated via 3D printing carbohydrate glass and soft silicone for application in soft robots. [ABSTRACT FROM AUTHOR]