Inspired by our bodies’ sensory capabilities, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences and the Wyss Institute for Biologically Inspired Engineering have developed a platform for creating soft robots with embedded sensors that can sense movement, pressure, touch, and even temperature. Integrating sensors within soft robots has been difficult in part because most sensors, such as those used in traditional electronics, are rigid. To address this challenge, the researchers developed an organic ionic liquid-based conductive ink that can be 3D printed within the soft elastomer matrices that comprise most soft robots.
To fabricate the device, the researchers relied on an established 3D printing technique developed in the lab of Jennifer Lewis, the Hansjorg Wyss Professor of Biologically Inspired Engineering at SEAS and Core Faculty Member of the Wyss Institute. The technique — known as embedded 3D printing — seamlessly and quickly integrates multiple features and materials within a single soft body. To test the sensors, the team printed a soft robotic gripper composed of three soft fingers or actuators. The researchers tested the gripper’s ability to sense inflation pressure, curvature, contact, and temperature. They embedded multiple contact sensors, so the gripper could sense light and deep touches.