# The Enhanced Adaptive Grasping of a Soft Robotic Gripper Using Rigid Supports
## 5 Conclusions  
We fabricated a soft robotic gripper with variable hardness and designed rigid supports to improve the grasping ability of the soft gripper. FEM simulations were conducted to assist in the design of the distribution of the silicones. A bending performance comparison test and lifting force measurement test were conducted to verify the bending curve design and the rigid supports design. The rigid supports increase the lifting force of the original soft gripper without the rigid supports by 150 \(\pm\) 20% in the same incremental pressure (26 kPa), and the level of performance improvement will be higher when the incremental pressure is higher. The soft robotic gripper coupled with rigid supports can adaptively grasp items with special shapes or large masses requiring low incremental pressure (object: about 75 mm in diameter, below 5 kg; pressure requirement: below 30 kPa) without the requirement of other complicated control algorithms like conventional rigid robotic grippers. In comparison with the previous soft gripper studies [3; 9; 10], the proposed soft gripper exhibits an excellent talent for grasping objects above 5 kg. In other words, the proposed soft gripper can grasp the same objects at lower incremental pressure. In terms of all varieties of existing soft grippers, what most of the research focused on turned out to be aerodynamic structure and materials. We paid close attention to the following question: \"How can the efficiency of the gripper's grasping ability at the same pressure condition be improved?\" Here are our solutions according to the paper. (1) The combined use of materials with different properties and a rational material layout can significantly improve the deformation situation of the gripper by more than four times better than a single use of the same material in variance of relative curvature value. (2) We propose a solution, which turns out to be the usage of a rigid structure to reduce the deformation of grabbing an item. In some way, the reduction in deformation means better efficiency.  
Although the current rigid supports can improve the grasping performance to a greater extent, they also limit the size of the grasping object (must be smaller than in diameter). Therefore, future work will be carried out to make the rigid supports deformable of their bending angle, which allows the gripper to grasp larger sizes of objects.  
Methodology, Z.P.; validation, Z.P., D.L., X.S., Y.R. and M.W.; investigation, Z.P., D.L., X.S., Y.R. and M.W.; data analyzation, Z.P.; visualization, Z.P.; writing--original draft preparation, Z.P.; writing--review and editing, J.P., Z.P., D.L., X.S., Y.R., and M.W.; supervision, Y.G. All authors have read and agreed to the published version of the manuscript.  
Figure 8: The comparison of lifting force between SPAs. The lifting force is plotted from previous research [3; 6; 7; 11; 20; 21]. Our work is plotted according to 3.4. lifting force measurement, which is highlighted in a yellow star.  
Funding: The authors would like to acknowledge the financial support from the National Natural Science Foundation of China (grant number: 52175248) and the Key R&D Program of Shaanxi, China (grant number: 2023-YBGY-358). Data