Vision-assisted 4D printing of a silicone gripper with integrated sensors and high energy density actuators

The study addresses a key challenge in soft robotics: making DIW-printed, ultra-soft silicone grippers that also include sensors and high-energy-density actuators, while still achieving 4D morphing. The authors present an automated “pause-and-go” additive manufacturing workflow. A 4-DOF pick-and-place robot and a computer vision system identify components and place them into the DIW process without manual intervention, embedding a flexible strain sensor and a coiled-shape memory alloy (SMA) actuator into the silicone matrix. They report that the embedded strain sensor provides feedback for proprioceptive and exteroceptive sensing, and that the SMA actuator response was characterized under different currents and loads. With the integrated sensor, the gripper supports closed-loop PI control of the SMA actuator, and the system was validated on a humanoid-mounted gripper performing real-world tasks across diverse object types.