Printed Bilayer Liquid Metal Soft Sensors for Strain and Tactile Perception in Soft Robotics

A liquid metal (LM) soft sensors for strain monitoring and self-powered tactile detection in soft robotics are developed. The sensor is fabricated by printing a bilayer of oxidized LM paste and bare LM on a soft substrate. This bilayer design overcomes the challenges in scalable printing of liquid metal and demonstrates soft sensors with exceptional electromechanical performance. Specifically, the sensor exhibits a strain sensing range of over 400% with a gauge factor of over 2, while displaying low hysteresis and high mechanical stability. Furthermore, the sensor utilizes a single electrode triboelectric effect to achieve self-powered tactile sensing. To demonstrate the potential of these sensors in soft robotics, it is integrated into a soft pneumatic actuator and successfully demonstrate their ability to perceive gestures, motion, and grasping. This work highlights the potential of LM-based soft sensors in advancing the field of soft sensing and soft robotics.

Automated summary

A liquid metal (LM) soft sensor has been developed for strain monitoring and self-powered tactile detection in soft robotics. The sensor is fabricated through printing a bilayer of oxidized LM paste and bare LM on a soft substrate. This bilayer design overcomes the challenges in scalable printing of liquid metal and shows exceptional electromechanical performance. Employing a single electrode triboelectric effect, the sensor achieves self-powered tactile sensing. Integrated into a soft pneumatic actuator, the sensor demonstrates its ability to perceive gestures, motion, and grasping. This work highlights the potential of LM-based soft sensors in advancing the field of soft sensing and soft robotics.