3D Printing of Electrically Conductive Silver Nanoparticle-Embedded Foams for Pressure Sensor Applications

Flexible pressure sensors with high sensitivity have gained considerable attention in the electronic skin, human motion control, and health monitoring fields. Porous structures strongly enhance the compressibility and sensitivity in piezoresistive sensors compared with bulk materials. However, traditional foam fabrication methods lead to poor adhesion between nanofillers and polymer matrix, instability, complexity, and low reproducibility. We report a single-step 3D printing process for silver nanoparticle-embedded foams, creating pressure sensors with controlled conductivity, shape, and stiffness. Our silver nanoparticle-embedded foam-based sensors achieve high sensitivity with a wide working range and minimal hysteresis. Additionally, these sensors demonstrated robust durability, maintaining consistent resistance signals across 250 cyclic tests, and are integrated into a pressure patch and smart shoe sole for human motion monitoring.