Dual bionic-inspired stretchable strain sensor based on graphene/multi-walled carbon nanotubes/polymer composites for electronic skin

With the rapid development of wearable electronic devices, stretchable strain sensors with wide strain range, high sensitivity, fast response, and high durability are urgently demanded. Here, a dual bionic-inspired stretchable strain sensor (DBSSS) with fingerprint patterns and biomimetic lotus root fiber structure is proposed. Silicone rubber (SR) is used as the encapsulation layer for the sensor, and multi-walled carbon nanotubes (MWCNT) are used as conductive bridges to connect graphene (GN) nanolaminates. The good cooperation of the two combined conductive materials with the fingerprint pattern structure significantly enhances the sensing function of DBSSS. DBSSS has high sensitivity (GF=35.33), wide strain sensing range (0–145%), fast response (∼80 ms), and good durability (>5000 cycles). Therefore, based on the excellent comprehensive performance of DBSSS, it can accurately realize gesture recognition, human micro-expression monitoring, and Morse code detection, which shows the broad application prospect of electronic skin.