Harvard team embeds touch sensitivity into soft robotics

Building on pioneering work by Jennifer Lewis, Professor of Biologically Inspired Engineering at the John A Paulson School of Engineering and Applied Sciences (SEAS), the Harvard team used a technique known as embedded 3D printing to incorporate an organic ionic liquid-based conductive ink into the elastic polymer materials that comprise soft robots.

The robot made by the team consisted of three grippers, with multiple contact sensors embedded into their structure. In a paper in Advanced Materials, the researchers detail how they tested the grippers’ ability to sense inflation pressure, curvature, contact and temperature.

"To date, most integrated sensor/actuator systems used in soft robotics have been quite rudimentary," said Michael Wehner, formerly postdoctoral fellow at SEAS, co-author of the paper, who has now moved to the University of California, Santa Cruz. "By directly printing ionic liquid sensors within these soft systems, we open new avenues to device design and fabrication that will ultimately allow true closed loop control of soft robots."