Hierarchical Wrinkles with Piezopotential Enhanced Surface Tribopolarity for High-Performance Self-Powered Pressure Sensor

Transfer-Printed Wrinkled PVDF-Based Tactile Sensor-Nanogenerator Bundle for Hybrid Piezoelectric-Triboelectric Potential Generation

Triboelectric sensors are known for their ultrahigh sensitivity and wide-range detectability of tactile force/pressure, all while being self-powered. However, the energy harvesting efficiency of triboelectric nanogenerators (TENGs) is often limited by relatively low output power density, when compared to other state-of-the-art microgenerators. To address this challenge and achieve high force/pressure detection while maintaining excellent tactile resolution, a hybrid nanogenerator is proposed that comprises of both triboelectric and piezoelectric components within a ferroelectric polyvinylidene fluoride (PVDF) polymer matrix. To enhance tactile sensitivity, a coupled transfer printed-spin coating technique is introduced to imprint wrinkled silicone structuring with tunable periodicity and amplitude directly onto PVDF. The hybrid output voltage of the wrinkled PVDF-based TENG utilizing the ferroelectric β phase of PVDF (FE-TENG_5) shows an impressive ≈200% increase compared to pristine FE-TENG. The highest power density (0.9 mW cm-2) corresponds to FE-TENG with the periodicity of 5 µm. Remarkably, the imprinted FE-TENGs can detect even the slightest tactile force (<2 N), while the hybrid mechanism ensures a broad force sensing range, extending up to 100 N before saturation. This exceptional performance establishes the imprinted PVDF-based FE-TENG as a versatile tactile sensing platform for a range of cutting-edge applications, particularly in electronic skin and next-generation microelectronics.

Lightweight and Strong Cellulosic Triboelectric Materials Enabled by Cell Wall Nanoengineering

As intelligent technology surges forward, wearable electronics have emerged as versatile tools for monitoring health and sensing our surroundings. Among these advancements, porous triboelectric materials have garnered significant attention for their lightness. However, these materials face the challenge of improving structural stability to further enhance the sensing accuracy of triboelectric sensors. In this study, a lightweight and strong porous cellulosic triboelectric material is designed by cell wall nanoengineering. By tailoring of the cell wall structure, the material shows a high mechanical strength of 51.8 MPa. The self-powered sensor constructed by this material has a high sensitivity of 33.61 kPa-1, a fast response time of 36 ms, and excellent pressure detection durability. Notably, the sensor still enables a high sensing performance after the porous cellulosic triboelectric material exposure to 200 °C and achieves real-time feedback of human motion, thereby demonstrating great potential in the field of wearable electronic devices.