Influence of Piezoresistive Material and Thickness on the Electromechanical Response of Flexible Pressure Sensors

Flexible piezoresistive sensors based on carbon-filled polyethylene (PE) and thermoplastic polyurethane (TPU) were compared. TPU sensors were fabricated by fused filament fabrication, enabling thickness control from 0.2 to 5 mm. Electrical resistance was measured under cyclic loading up to 250 kPa. TPU shows improved repeatability and a sixfold reduction in drift (35 Ω vs 330 Ω). Increasing thickness reduces sensitivity but limits saturation, enabling tuning of the sensor response. TPU provides a more stable and configurable alternative to PE.