High‐Precision Piezoresistive Sensors Based on Femtosecond Laser Preparation of Conductive PDMS Composites With Microarray Structure

ABSTRACTThis study addresses challenges in developing high‐performance flexible pressure sensors by innovating material composition and microstructure design. Using PDMS as a substrate with carbon fiber and graphene fillers, the team fabricated piezoresistive materials via space‐limited assembly. A femtosecond laser etched grooves and columnar microstructures onto the surface, enhancing sensor performance. The microstructures, smaller than carbon fibers, localized graphene in piezoresistive regions, boosting sensitivity, while carbon fibers formed a conductive network elsewhere. Testing revealed that reducing piezoresistive material thickness significantly improved sensitivity: a 0.1 mm layer achieved 1.36 kPa−1, 74% higher than 0.2 mm. Optimizing microstructure geometry enhanced performance: a 0.3 mm pillar‐array sensor achieved 1.87 kPa−1 sensitivity (vs. 1.11 kPa−1 for grooves and 0.62 kPa−1 for non‐structured), with 0.998 linearity. The spatial confinement assembly enabled localized graphene distribution in piezoresistive regions, amplifying stress concentration effects. These results highlight that thinner materials and tailored microstructures amplify sensitivity and linearity by concentrating stress and homogenizing conductive pathways. The findings demonstrate a viable strategy for creating high‐precision, flexible pressure sensors, advancing applications in health monitoring and wearable technology through improved electromechanical coupling and structural design.