A Miniature Soft Robotic Manipulator Based on Novel Fabrication Methods

Flexible robotic manipulators have been widely used in minimally invasive surgery (MIS) and many other applications requiring closer inspection and operation. Although a variety of manipulators enabled by different mechanism have been developed, few of them can preserve softness, thinness, and decent bending capability simultaneously. In this letter, we present a miniature soft robotic manipulator made of hyper-elastic silicone rubber. Along with the manipulator design, two novel fabrication methods are proposed and elaborated. Detailed characterizations are specified to show the bending capability of the manipulator given different air pressure. Specifically, our manipulator, as thin as 6 mm, is able to achieve 360° directional bending, and, when given pressure over 70 kPa, it can reach 180° bending angle and around 5 mm bending radius easily. Due to its innate compliance and small dimension, this type of robotic manipulator can deliver safe and comfortable interactions with the subjects. More significantly, the novel fabrications in this letter diversify the fabrication methods for soft pneumatic robots and actuators (SPRA) and further scale down their sizes.