Large-Scale Nanofiber Manufacturing| An All-Nanofiber-Based CustomizableBiomimetic Electronic Skin for Thermal-Moisture Management and Energy Conversion

Professor Wei Qufu from Jiangnan University & Researcher Lü Pengfei, Associate Professor Guo Jiaxiang from Tianjin University: All-Nanofiber-Based Biomimetic Electronic Skin for Thermal-Moisture Management and Energy Conversion

Developing electronic skin (e-skin) with extraordinary sensing capabilities through biomimetic strategies holds great potential for wearable electronics in IoT and human-machine interaction. However, sweat accumulation on skin surfaces severely affects the stability and accuracy of e-skin patch sensing signals, and wearing comfort with stable functional interfaces remains a major challenge.

Recently, Professor Wei Qufu and Researcher Lü Pengfei's team from Jiangnan University, in collaboration with Associate Professor Guo Jiaxiang's team from Tianjin University, published their latest research "An All-Nanofiber-Based Customizable Biomimetic Electronic Skin for Thermal-Moisture Management and Energy Conversion" in Advanced Fiber Materials. Inspired by the dual hydrophilic/hydrophobic structure of lotus leaves, the researchers developed a unidirectional water-transport e-skin (UWTES) with gradient pore structure through continuous manufacturing combining electrospinning and screen printing. The alloying effect of liquid metal with silver nanosheets effectively solved substrate affinity issues.Due to PVDF-HFP's excellent triboelectric properties, UWTES was applied as a flexible triboelectric nanogenerator (UT-TENG), achieving both energy sensing and generation functions. Integrating UT-TENG with deep learning algorithms created a gait recognition system with 99.7% accuracy for detecting human motion states. As proof-of-concept, the temperature visualization system (TUWTES) demonstrated reliable color switching from 25°C to 40°C without external power, enabling body temperature monitoring.

Fig. 1: Structural characteristics, multifunctionality and potential applications of TUWTES textile.

Fig. 2: Fabrication and characterization of UWTES and TUWTES fabrics.

UWTES and TUWTES were prepared via one-step electrospinning and screen printing. SEM showed smooth gradient pore networks with average pore sizes of 19.95 μm and 9.7 μm (Fig.2b-c). After screen-printing LM-Ag, TUWTES maintained stable 4-layer structure (342μm thick) with smooth surface (Fig.2d). Stress-strain curves confirmed 3D interconnected networks suitable for wearable applications.

Fig. 3: Unidirectional water transport properties, air permeability and moisture permeability of UWTES fabric.

The UWTES e-textile, fabricated through induced surface energy gradient differentiation, successfully achieved unidirectional moisture transport and spontaneous absorption. With an air permeability of 26.5 mm/s and moisture permeability of 1725.7 g/(m²·day), it ensures wearing comfort over extended periods. This property is particularly significant for facilitating excess body heat dissipation and rapidly reducing thermal risks after intense physical activity.

Fig. 4: Triboelectric output performance of UWTES fabric.

Fig. 5: Self-powered sensing applications of UT-TENG.

The UWTES-based triboelectric nanogenerator (UT-TENG) demonstrated exceptional electromechanical performance, exhibiting an open-circuit voltage of 188.7 V and short-circuit current of 18.89 μA, along with outstanding cycling stability. When integrated at key human motion points, it accurately and sensitively monitors subtle movement variations, showcasing impressive self-powered sensing capabilities.

Fig. 6: Application of UWTES fabric in motion gait perception.

By incorporating machine learning algorithms, we developed a gait recognition system integrating UT-TENG into smart insoles, achieving a high recognition accuracy of 99.7%. The system maintained robust performance with accuracies of 94.9%, 99.4%, and 99.8% under varying external loads and sensor positions, validating the model's excellent classification precision, generalizability, and robustness.

Figure 7: Thermochromic and Joule heating properties of TUWTES fabric.

The TUWTES textile, created by integrating thermochromic microcapsules with different color-changing temperatures into UWTES, enables real-time visual monitoring and early warning of body temperature during high-intensity exercise. Cyclic heating tests with repeated 0.3 V DC voltage application demonstrated reproducible and rapid temperature response between room temperature and 76.2°C. These findings confirm the programmable customization capability and body temperature monitoring function of the smart textile, prompting timely protective measures or medical assistance during overheating, particularly for elderly and pediatric populations.

In summary, we developed a unidirectional water-transport triboelectric e-skin (UWTES) for human gait recognition, based on heterogeneous nanofiber membranes and controllable liquid metal-based conductive coatings. The UT-TENG integrated with machine learning achieves 99.7% gait monitoring and analysis accuracy. TUWTES fabric enables real-time visual temperature monitoring during intense exercise through thermochromic microcapsules. As proof-of-concept, this innovative breathable, self-powered e-skin design provides new insights for applications in smart sensing textiles, rehabilitation medicine, soft robotics, and human-machine interaction.

Original article: https://doi.org/10.1007/s42765-025-00541-w