Hierarchically Designed Super‐Elastic Metafabric for Thermal‐Wet Comfortable and Antibacterial Epidermal Electrode

Abstract

On-skin electronic systems represent a burgeoning technology that develops wearable devices capable of adapting to the dynamic surfaces of the human body. Present film-based electronics are constrained to single-layered constructions on impermeable substrates that severely inhibit their wearing comfort and multi-functionality. Herein, a thermal-wet comfortable and antibacterial epidermal electrode is hierarchically designed on an ultra-stretchable metafabric. Via the layer-by-layer assembly of trilayered elastomeric fibers with multi-scale sizes and varied compositions, porosity and wettability asymmetries are established across the nonwoven fabric, rendering it with unidirectional liquid conduction and sweat self-pumping performance. The successful printing of stretchable liquid-metal (EGaIn) circuits on ZnO NPs anchored microfibers simultaneously equips the trilayered metafabric with robust antibacterial capability, low-watt heating ability, and high-fidelity detectability for surface electromyography signals of various physical activities. Moreover, the incorporation of thermochromic microcapsules in the outmost fibers also enables the fabric Joule heater with visual indicating ability via reversible color-switching. Thus, this hierarchically engineered epidermal electrode with thermal-wet comfort and antibacterial ability holds great promise in daily applicable healthcare and sports monitoring electronics.

High-performance sensing, breathable, and biodegradable integrated wearable sweat biosensors for a wireless glucose early warning system

“…The capillary force ( F C ) was calculated according to Laplace's equation (Laplace pressure = 4 γ cos θ / D , where γ is the surface tension of the liquid, θ is the WCA of the inner surface of the capillary, and D is the pore size of the fibrous membrane). 48 Due to the different pore sizes and the WCA of the two layers, the F C of the sweat drop varies in the corresponding capillary channels. 49 The drops are absorbed into the pores by the capillary force upon contact with the hydrophobic side of hydrophilic–hydrophobic fibrous mats.…”

Liquid Metal-Based Electronics for On-Skin Healthcare

“…The most common way to prevent the leakage of LM is based on physical encapsulation with elastomers. The encapsulation layers serve in the form of a condensed elastomer film [95], electrospun mat [124], and sheath for the core conductive fibers [78]. Second, other nanomaterials and novel structures have been introduced to LM conductive networks, such as the carbon nanofiber protection layer on LM particles in [125] and the microgrooves design for the abrasion resistance of LM in [126].…”

Dynamically Tunable Subambient Daytime Radiative Cooling Metafabric with Janus Wettability

“…[ 2a,11 ] The radiative cooling materials are required to have high reflection in the solar wavelength range (0.25–2.5 µm) to minimize the heat input, and also strongly emit/transmit human body infrared radiation (HBIR, 7–14 µm) to maximize the heat output. [ 4a,7a,12 ] In an outdoor environment, the sky (at a temperature of 3 K) has a better cooling effect than that of the surrounding environment. Therefore, textiles with high emissivity in ATSW range have the potential to reach a subambient cooling temperature.…”