Ultra-sensitive flexible stretchable sensor based on bionic structure using graphene oxide and carboxylated multi-walled carbon nanotubes for wearable electronic skin

• Flexible stretchable sensor based on biomimetic structures. • Graphene oxide and carboxylated multi-walled carbon nanotubes are employed as synergistic conductive sensing materials. • The flexible stretchable sensor with high sensitivity and sensing range. • Flexible stretchable sensors are applied to demonstrate wearable electronic skin. Flexible stretchable sensors have recently attracted significant attention due to their great potential in detecting human joint posture and monitoring health. However, fabricating stretchable sensors that combine ultrasensitive responsiveness with fast response times over a wide strain range remains a major challenge. To address this issue, this study presents an ultrasensitive flexible stretchable sensor (FSS) based on a biomimetic structure, utilizing graphene oxide and carboxylated multi-walled carbon nanotubes as synergistic conductive sensing materials. The FSS exhibited excellent performance, including a strain gauge factor of up to 84.942, a sensing range of up to 160 %, a lower strain detection limit of 0.25 %, and rapid response and recovery times50 ms and 70 ms, respectively. Additionally, FSS is successfully applied to Morse code messaging, motion monitoring, and sitting posture recognition, highlighting its potential for wearable electronic skin applications.