In Situ Laser-Induced Graphene on PEEK/Ecoflex Composites for Stretchable Strain Sensing

Laser-induced graphene (LIG) technology has attracted considerable attention in the fabrication of wearable and flexible sensors. To enhance the sensor stretchability, LIG is typically transferred to a stretchable substrate after fabrication. However, this transfer process is complex and often degrades the graphene quality. This study proposes an in situ LIG process based on a modified stretchable substrate. The substrate is fabricated by mixing the poly(ether ether ketone) (PEEK) and Ecoflex, which offers excellent elongation that can be stretched to around 480%. The optimized laser processing can achieve the fabrication of sensors with a remarkable initial resistance of ∼170 Ω, a high gauge factor (GF) of ∼869, and a measurable strain range of ∼20%. It conforms well to human joints, making it suitable for motion detection in VR-based martial arts and boxing games, enabling accurate posture recognition.