Wound healing and tissue repair are recognized as basic human health problems worldwide. Attempts to accelerate the reparative process are focused on developing functional wound dressings. Herein, we present novel Janus textiles with anisotropic wettability from hierarchical microfluidic spinning for wound healing. The hydrophilic hydrogel microfibers from microfluidics are woven into textiles for freeze-drying treatment, followed by the deposition of electrostatic spinning nanofibers composed of hydrophobic polylactic acid (PLA) and silver nanoparticles. The electrospun nanofiber layer can be well coupled with the hydrogel microfiber layer to generate Janus textiles with anisotropic wettability due to the roughness of the hydrogel textile surface and the incomplete evaporation of PLA solution when reaching the surface. For wound treatment with the hydrophobic PLA side contacting the wound surface, the wound exudate can be pumped from the hydrophobic to the hydrophilic side based on the wettability differential derived drainage force. During this process, the hydrophobic side of the Janus textile can prevent excess fluid from infiltrating the wound again, preventing excessive moisture and preserving the breathability of the wound. In addition, the silver nanoparticles contained in the hydrophobic nanofibers could impart the textiles with good antibacterial effect, which further promote the wound healing efficiency. These features indicate that the described Janus fiber textile has great application potential in the field of wound treatment.
A large of energy consumption is required for indoor and outdoor personal heating to ameliorate the comfortable and healthy conditions. Main personal thermal management strategy is to reflect mid-infrared human body radiation for human surface temperature ( T HS ) regulation. We demonstrate a visible Janus light absorbent/reflective air-layer fabric (Janus A/R fabric) that can passively reflect radiative heating meanwhile can actively capture the solar energy. A series of azobenzene derivatives functionalized with alkyl tails are reported to co-harvest the solar and phase-change energy. The T HS covered by Janus A/R fabric can be heated up to ~ 3.7 °C higher than that covered by air-layer fabric in cold environment (5 °C). Besides, integrating the thermo- and photo-chromic properties is capable of monitoring comfort T HS and residue energy storage enthalpy, respectively. According to the colour monitors, intermittent irradiation approach is proposed to prolong comfortable- T HS holding time for managing energy efficiently. Graphical Abstract For the personal thermal management, we fabricate a visible Janus light absorbent/reflective fabric, which can actively capture solar energy and passively reflect the human radiation reflection (MIR). The solar energy can be released as heat to actively warm human surface temperature up, and the reflective MIR can passively heat the human body. The surface temperature and residue energy storage can be monitored by distinct colour change.
Due to the increased demand for health monitoring and disease alarm, the self-powered epidermal electric sensors have attracted extensive attention, such as triboelectric nanogenerator (TENG)-based electric skin (e-skin). However, the humidity accumulation at the interface between e-skin and skin will threaten the stability and reliability of the monitoring signals. Moisture absorptivity and perspiration are still great challenges that need to be addressed. Here, inspired by the internal structure of plants used to transport water, we fabricated an all-nanofiber Janus textile via a continuous electrospinning/electrospray technology, presenting a double gradient variations in the pore size and wettability along the thickness direction. Janus textile was constructed from the hydrolyzed polyacrylonitrile (HPAN)/hexagonal boron nitride nanosheets (BNNS) fibrous membrane with small pores and hydrophilicity , conducting Ag nanowire (NW)layer, and polyurethane (TPU) nanofibrous membrane with large pores and hydrophobicity . By utilizing the wicking effect of external HPAN/BNNS layer, the sweat droplet could be transported from the interface between the skin and Janus textile to the external environment, meanwhile, the returned sweat will be blocked by interior TPU layer to keep the dry state of the skin. Therefore, the directional moisture transportation was realized. As the near-skin side, TPU was used as the other triboelectric layer, the optimal triboelectrification output reached 78.10 V, 0.16 μA, and 3.31 W m −2 . Moreover, the damped Janus textile also exhibited an open-circuit voltage of 30 V, a short-circuit current of 0.051 μA, and a power density of 0.14 W m −2 . With the assistance of an adhesive layer , Janus textile e-skin could easily adhere to the skin surface, generating stable movement and physiological sensing signals. In short, this work presents a noval way to construct Janus e-skin patch with directional sweating and breathability for monitoring long-term real-physiological signals.