Electrospinning Equipment: Semi-bonded Triboelectric E-Textile for Skin Thermal Regulation and Self-Powered Sensing

With the widespread application of wearable electronic devices in fields such as healthcare and human - machine interaction, the requirements for self - power supply and thermal management of skin - attachable electronic devices are increasing day by day. However, traditional devices rely on external power sources and have poor heat dissipation. Triboelectric nanogenerators (TENGs) have become a research hotspot due to their high - efficiency energy conversion and self - power - supply characteristics. Nevertheless, their structural design still faces challenges, especially in achieving high energy output while maintaining comfort and flexibility.

The research team led by Prof. Yunpeng Huang from Donghua University published a research paper titled "Robust Triboelectric E - Textile with Semi - bonded Bilayers for On - Skin Thermal Regulation and Self - Powered Motion Monitoring" in the journal Advanced Fiber Materials. This paper introduced a bilayer electronic textile (TR - TENG e - textile) that integrates thermal regulation and self - powered motion monitoring. This fabric realizes efficient solar reflection, infrared emission, and stable triboelectric performance through a semi - bonding assembly method, providing an innovative solution for next - generation smart fabrics.

To achieve comfortable and self-powered human motion monitoring, the team developed a highly robust thermally regulating triboelectric e - textile (TR - TENG e - textile). The preparation process involves electrospinning device to prepare non - woven styrene-ethylene-butylene-styrene (SEBS) textiles and fixing highly reflective and electronegative polyvinylidene fluoride - trifluoroethylene (PVDF - TrFE) nanoparticles in them. At the same time, electrospinning machine is used to prepare polyvinyl alcohol (PVA) nanofibers embedded with highly emissive and electropositive silicon dioxide (SiO2​) nanoparticles. The detailed preparation process is shown in Fig. 1a.

Fig. 1 a. Schematic diagram of the design and preparation of the semi - bonded TR - TENG e - textile; b. SEM image of the cross - section of the semi - bonded TR - TENG e - textile; c. Digital image of the TR - TENG e - textile; d. Schematic diagram of the 90 - degree peeling test; e, f. Peeling strength of the bilayered TR - TENG e - textile assembled under different hot - pressing durations; g. Water permeability tests of different textile samples.

To seamlessly assemble these two layers of materials, the team used the hot - press needle - punching method. A customized needle was used to hot - press and needle - punch the two layers of materials at 95°C and 0.3 kPa for 5 minutes, forming a semi - bonded interface between the two layers. This interface not only promotes electrostatic equilibrium but also ensures sufficient integrity of the bilayer structure (Fig. 1b). In addition, a flexible liquid metal (LM) circuit is sandwiched between the two layers. The LM circuit can achieve fast charge transfer and also has an additional Joule heating function. It can increase the temperature by 16.6°C under a voltage of 3.6V (Fig. 2b). The triboelectric nanogenerator constructed from the two prepared layers of materials exhibits excellent triboelectric output performance. Tests show that under a pressure of 30 N, it can generate a voltage of 20.3 V and a current of 15.3 nA (Fig. 3b, c).

Fig. 2 a. Relative resistance of the TR - TENG e - textile under different strains (the inset shows the e - textile at elongations of 0% and 400%); b. Schematic showing the structure of the Joule heater in the TR - TENG e - textile; c. Surface temperatures of the TR - TENG e - textile under varied voltages; d. Surface temperatures and corresponding IR images of the Joule heater under different strains; e. Thermal responses of the Joule heater under 1.2 V, 1.8 V and 2.4 V for 10 cycles; f. Surface temperature of the TR - TENG e - textile when applied as on - skin heating patches.

Fig. 3 a. Triboelectric testing mechanism of PVDF - TrFE@SEBS and SiO2​/PVA textile electrodes; b, c. Triboelectric output voltage and current under different contact forces (0.3, 0.5, 1.0, 10, 20 and 30 N); d. Triboelectric output voltage and current under different contact frequencies (0.5, 1 and 2 Hz); e. Long - term stability of triboelectric output under 3000 cycles; f. Equivalent circuit diagram showing the textile TENG connected to a bridge rectifier to charge different capacitors; g. Charging performance for different capacitors (470, 1000 and 3300 nF); h. Real - time curve of charging and discharging a stopwatch.

This novel TR - TENG e - textile is seamlessly integrated through the hot - press needle - punching method, forming a semi - bonded interface between PVDF - TrFE@SEBS and SiO2​/PVA textiles. It not only achieves stable energy conversion efficiency but also reaches a high emissivity of 96.2% in the mid - infrared - far - infrared (MIR - FIR) band and a high reflectivity of 83.1% in the ultraviolet - visible - near - infrared (UV - VIS - NIR) band (Fig. 4b).

Fig. 4 a. Radiation cooling mechanism of the TR - TENG e - textile; b. Reflectivity and emissivity spectra of the SiO2​/PVA, PVDF - TrFE@SEBS and TR - TENG e - textiles (0.3 - 25 μm); c. Digital photograph of the homemade test device for passive cooling; d - f. Continuous temperature and solar irradiance measurements of the textile samples under the clear day and g - i cloudy day; j, k. Practical cooling tests of the TR - TENG e - textile and other textile samples on human skin.

When the TR - TENG e - textile is used as a skin - attachable self - powered sensing device, it has excellent passive cooling performance. In actual tests, the temperature can be reduced by 18.4°C in sunlight and 12.6°C on cloudy days, which can effectively relieve the sultriness of the human body when wearing electronic devices for a long time (Fig. 4d - f). At the same time, it can provide stable self - powered motion detection for human activity monitoring and can faithfully recognize high - frequency motions and subtle movements such as swallowing, running, and breathing (Fig. 5a - h).

Fig. 5 a, b. Schematic of the application and operating principle of the TR - TENG e - textile for self - powered motion monitoring. Signals detected by the e - textiles corresponding to human activities include c swallowing, d nodding, e knee bending, f eye blinking, g breathing and h running.

Article source: https://doi.org/10.1007/s42765-025-00546-5