High Sensitivity, All-Organic Piezoelectric Skin Enabled by a Phytic Acid-Assisted Molecular Engineering Strategy

Electronic skin (e-skin), which mimics the tactile and multimodal sensing functions of human skin, is emerging as a key technology for wearable healthcare and human-machine interfaces. All-organic piezoelectric composites owing to their intrinsic flexibility and skin conformability represent attractive candidates for e-skin development. However, achieving a high piezoelectric performance, long-term stability, and mechanical compliance simultaneously remains a critical challenge. Here, we report a phytic acid (PA)-assisted molecular engineering strategy to fabricate P(VDF-co-trifluoroethylene) (PVDF-TrFE)/PA composites with a high piezoelectric charge coefficient (87 pC N^-1) and voltage coefficient (614 mV m N^-1), as well as durability. Strong hydrogen bonding between PA hydroxyl groups and PVDF-TrFE chains promotes β-phase crystallization and stabilizes the piezoelectric structure. Meanwhile, the high dielectric constant of phosphate groups enhances the dipole polarization efficiency. Building on this composite, we developed a high-performance piezoelectric skin (pe-skin), which exhibits high sensitivity (35 mV kPa^-1), a fast response (∼70 ms), and robust stability. The resulting pe-skin enables real-time physiological monitoring, precise pressure mapping, and smart human-machine interfaces. Overall, this work highlights a promising pathway toward the construction of high-performance pe-skin for healthcare, robotics, and human-machine interfaces.