Damping effect of particle-jamming structure for soft actuators with 3D-printed particles

Soft actuators made of soft materials can exhibit compliant behavior but tend to generate large vibrations in dynamic environments because of poor damping performance. Here, we integrate the particle-jamming technology with three-dimensional (3D)-printing technology to enhance the damping performance, with a goal of establishing a lightweight and reliable approach of damping for the soft actuators. An analytical model for energy dissipation is presented, which can reveal the dependence of the damping performance on various parameters including vacuum pressure, particle chamber dimensions, and particle properties. Then, 3D-printed particles with different sizes and different surface topographies are fabricated. The theoretical analysis and experimental results are combined to investigate the dependence of the particle chamber's damping effect on specific parameters such as vacuum pressure, the dimensions of the particle chamber, and the diameter and surface topography of the particle. Accordingly, the damping for the soft chamber with particles can be tuned well. The experimental results show that up to a six-fold increase in damping ratio is achieved. Thus, this research can provide insights for designing soft actuators where vibration suppression is important, particularly in some dynamic environments.