High Strain-Insensitive Performance Stretchable Pressure Sensor Based on the Laser-Engraved Graphene with a Serpentine Nested Structure

Stretchable piezoresistive pressure sensors are susceptible to tensile strain, leading to signal cross-talk and inaccurate pressure measurements. Therefore, it is a challenge to find an effective method to reduce the effect of tensile strain on stretchable piezoresistive pressure sensors. Herein, a strain-insensitive stretchable pressure sensor (SISPS) with a serpentine nested structure was constructed through laser engraving of graphene. The strain dispersion effect of the serpentine nested structure reduced the variation in relative resistance of the sensor to only 0.3% under 80% tensile strain, resulting in significant strain-insensitive performance. The obtained sensor demonstrated high sensitivity (1.41 x 10-1 kPa-1), broad sensing range (0-50 kPa), short response time (100 ms), low detection limit (100 Pa), and good cyclic stability (3000@10 kPa). The sensor was capable of accurately detecting human physiological and body motion signals including pulse, muscle movement, and laryngeal vocalizations.