Soft grips are best for handling heavy objects and complex shapes. To achieve this, we need to consider both the design and the material constraints. We used a 3D printer to print two moulds on which we measured the compressive forces at specific bending angles and compared the results. In order to predict the crack locations, we used the same material in a tensile test and investigated whether we could predict the stress-strain curve of the material under certain assumptions. As we could not achieve high forces with resin, we decided to use NBR70 rubber. The compound was vulcanized in moulds with different depths and at different times. We used a 30-tonne hydraulic press in which we then installed all the necessary tools. Later, numerous tensile tests were carried out on homogeneous vulcanized, cut and then bonded rubber with Loctite 480 adhesive and with intermediate reinforcements. The purpose of these tests was to determine how stress and strain change with certain changes compared to the intact sample. We found that a soft gripper with a constant chamber height provides much higher forces, up to 14 N, compared to a gripper where the chamber height decreases with the length of the gripper and only a force of 9 N is achieved.
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