An Elephant Trunk-Inspired Modular Variable Stiffness Soft Robot

The Elephant Trunk demonstrates unique advantages in complex environments thanks to its flexibility, high degree of freedom and versatile transport characteristics. In the industrial world, it is known as nature's universal robotic arm. However, the ability to achieve three-dimensional smooth movement and stiffness adjustment similar to that of the elephant trunk puts forward higher requirements on the structural design, drive integration and functional adaptability of the robot. Here I proposed and implemented a bionic elephant trunk robotic system that incorporates a modular architecture, soft actuators, and adjustable stiffness mechanisms, with 3D motion achieved by three 120 degrees soft bellows actuators working in concert, and thus possessing continuous deformation and spatial localization capabilities. In addition, in order to cope with the demand of rigid-flexible switching for different grasping tasks, the system introduces a variable stiffness mechanism based on skeleton-particle coupling, which is capable of state adjustment and structural toughening under external loads. In the end-operation environment, the robot integrates soft suction cups with adsorption functions. This effectively improves the stability of non-regular target attachment and grasping. The system is modeled using SOLIDWORKS software and the soft actuator is constructed using 3D printing and silicone injection moulding. Experimental results show that the robot exhibits excellent adaptability, load capacity, and locomotion in multi-scenario operations. It shows its wide potential in the direction of complex environment manipulation such as service robots.