LAUSR

Quantitative information of the magnitudes and directions of multiple contacting forces is crucial for a wide range of applications including human-robot interaction, prosthetics, and bionic hands. Herein we report a highly stretchable sensor integrating capacitive and piezoresistive mechanisms for simultaneous measurement of multiple forces. The sensor consists of three layers in a sandwich design. The two faces serve the dual functions of being piezoresistive sensors and the electrodes for the capacitive mode at the same time. Both the core and the faces are made of porous structures by a simple sugar particle template technique to give them high stretchability, with the faces containing segregated conductive networks of silver nanowires (AgNWs) and carbon nanofibers (CNFs) while the middle core is a non-conductive dielectric layer. By measuring the changes in resistance of the faces (Ra and Rb) and the capacitance (C) between the faces, three separate mechanical stimuli can be determined, including normal pressure, lateral strain, and shear force. The newly-developed multi-directional sensor offers a significant opportunity for the next generation of robotic arms, prosthetics, and artificial haptic systems.