Ultra-Stretchable and Force-Sensitive Hydrogels Reinforced with Chitosan Microspheres Embedded in Polymer Networks

An ultra-stretchable and force-sensitive hydrogel with surface self-wrinkling microstructure is demonstrated by in situ synthesizing polyacrylamide (PAAm) and polyaniline (PANI) in closely packed swollen chitosan microspheres, exhibiting ultra-stretchability (>600%), high sensitivity (0.35 kPa^-1 ) for subtle pressures (<1 kPa), and can detect force in a broad range (10² Pa-10¹ MPa) with excellent electrical stability and rapid response speed, potentially finding applications for E-skin.