Fig. 6: Interactive teaching of the self-reacting soft manipulator in 2D and 3D space.

a Tactile and touchless signals of the FBSS during two-dimensional teaching process, and the time instants of a user teaching the soft manipulator to grasp an object in a touchless manner. i Before bending & grasping the soft manipulator, the user chose an adequate length of the soft manipulator by controlling the distance between the hand and the FBSS (orange shading). ii The user initially applied a large step size by putting a hand very close to the FBSS (blue shading), then in step iii applied a small step control by keeping a short distance from the FBSS (green shading). iv When the soft gripper reaches the object, the user pressed the FBSS “button” to grasp the object (purple shading). b–d Comparison of teaching and repeating trajectories while grasping objects in three different positions. e Tactile and touchless signals of FBSS I and II during three-dimensional teaching, and time instants of a user touchlessly teaching the soft manipulator to grasp an object in three-dimensional space. i The user controlling planar bending in large steps with left-hand approaches toward the FBSS I (blue shading). ii The user controlling planar bending in small steps (also with left-hand approaches toward FBSS I) (purple shading). iii The user controlling out-of-plane bending with right-hand approaches toward FBSS II (green shading). iv When the soft gripper reaches the object, the user presses the FBSS “button” to grasp the object (orange shading). f–h Comparison of teaching and repeating trajectories while grasping objects in three different positions. The trajectories are illustrated in three-dimensional space (x–y, y–z, and x–z planes).