During impact, both the protecting 3D structure and the soft brain-like gel rapidly deform, as shown by the high-speed images in Figure . After impact, both the 3D structure and the gel rebound and return to their initial position. Based on the image series, we extract the height of the soft brain-like gel and calculate the average strain and acceleration associated with the gel deformation, as shown in Figure and listed in Table . Simultaneously, we record the voltage from the piezoelectric sensor which is proportional to the impact force. The extremely short response time (~1 ms) of the piezoelectric sensor allows for quantifying the dynamic change of force during the impact test. We repeat each measurement at least five times to ensure sufficiently powered statistics. With the protection of a 3D printed structure, the maximum extent of deformation is not only reduced but also delayed (Figure ). In delaying the impact, the protection structure reduces acceleration (Figure ,ii). Likewise, the voltage magnitude and thus the impact force is reduced across the whole impact tests (Figure ,iii). These results highlight the ability of 3D printed soft and stretchable elastomers to protect the soft brain-like gel from impacts.