Colorful Conductive Threads for Wearable Electronics: Transparent Cu-Ag Nanonets

Core-Sheath Heterogeneous Interlocked Conductive Fiber Enables Smart Textile for Personalized Healthcare and Thermal Management

Whereas thermal comfort and healthcare management during long-term wear are essentially required for wearable system, simultaneously achieving them remains challenge. Herein, a highly comfortable and breathable smart textile for personal healthcare and thermal management is developed, via assembling stimuli-responsive core-sheath dual network that silver nanowires(AgNWs) core interlocked graphene sheath induced by MXene. Small MXene nanosheets with abundant groups is proposed as a novel "dispersant" to graphene according to "like dissolves like" theory, while simultaneously acting as "cross-linker" between AgNWs and graphene networks by filling the voids between them. The core-sheath heterogeneous interlocked conductive fiber induced by MXene "cross-linking" exhibits a reliable response to various mechanical/electrical/light stimuli, even under large mechanical deformations(100%). The core-sheath conductive fiber-enabled smart textile can adapt to movements of human body seamlessly, and convert these mechanical deformations into character signals for accurate healthcare monitoring with rapid response(440 ms). Moreover, smart textile with excellent Joule heating and photothermal effect exhibits instant thermal energy harvesting/storage during the stimuli-response process, which can be developed as self-powered thermal management and dynamic camouflage when integrated with phase change and thermochromic layer. The smart fibers/textiles with core-sheath heterogeneous interlocked structures hold great promise in personalized healthcare and thermal management.

Ultrastretchable E-Skin Based on Conductive Hydrogel Microfibers for Wearable Sensors

Conductive microfibers play a significant role in the flexibility, stretchability, and conductivity of electronic skin (e-skin). Currently, the fabrication of conductive microfibers suffers from either time-consuming and complex operations or is limited in complex fabrication environments. Thus, it presents a one-step method to prepare conductive hydrogel microfibers based on microfluidics for the construction of ultrastretchable e-skin. The microfibers are achieved with conductive MXene cores and hydrogel shells, which are solidified with the covalent cross-linking between sodium alginate and calcium chloride, and mechanically enhanced by the complexation reaction of poly(vinyl alcohol) and sodium hydroxide. The microfiber conductivities are tailorable by adjusting the flow rate and concentration of core and shell fluids, which is essential to more practical applications in complex scenarios. More importantly, patterned e-skin based on conductive hydrogel microfibers can be constructed by combining microfluidics with 3D printing technology. Because of the great advantages in mechanical and electrical performance of the microfibers, the achieved e-skin shows impressive stretching and sensitivity, which also demonstrate attractive application values in motion monitoring and gesture recognition. These characteristics indicate that the ultrastretchable e-skin based on conductive hydrogel microfibers has great potential for applications in health monitoring, wearable devices, and smart medicine.

Versatile Liquid Metal/Alginate Composite Fibers with Enhanced Flame Retardancy and Triboelectric Performance for Smart Wearable Textiles

Liquid metal (LM) shows the superiority in smart wearable devices due to its biocompatibility and electromagnetic interference (EMI) shielding. However, LM based fibers that can achieve multifunctional integrated applications with biodegradability remain a daunting challenge. Herein, versatile LM based fibers are fabricated first by sonication in alginate solution to obtain LM micro/nano droplets and then wet-spinning into LM/alginate composite fibers. By mixing with high-concentration alginate solution (4-6 wt.%), the LM micro/nano droplets stability (colloidal stability for > 30 d and chemical stability for > 45 d) are not only improved, but also facilitate its spinning into fibers through bimetallic ions (e.g., Ga3+ and Ca2+ ) chelation strategy. These resultant fibers can be woven into smart textiles with excellent flexibility, air permeability, water/salt resistance, and high temperature tolerance (-196-150 °C). In addition, inhibition of smoldering result from the LM droplets and bimetallic ions is achieved to enhance flame retardancy. Furthermore, these fibers combine the exceptional properties of LM droplets (e.g., photo-thermal effect and EMI shielding) and alginate fibers (e.g., biocompatibility and biodegradability), applicable in wearable heating devices, wireless communication, and triboelectric nanogenerator, making it a promising candidate for flexible smart textiles.

Thermally Laminated Lighting Textile for Wearable Displays with High Durability

Textile-based light-emitting devices are attracting more and more attention because of their potential applications in smart clothing, human-computer interfaces, safety warnings, entertainment fashion, etc. However, simple and efficient manufacturing of luminescent devices on fabrics even clothing with excellent stretchability and washability remains challenging. Here, a solvent-free thermal lamination process combined with laser engraving has been proposed to fabricate electroluminescent (EL) devices on textiles. All the preprepared components, such as the bottom electrode, the EL layer, and the top transparent electrode, were thermally laminated on the surface of textiles employing thermoplastic polyurethane (TPU) as the binding matrix. The stretchability, luminance, and interface adhesion of the EL devices were systematically studied, showing excellent mechanical durability at high temperature, in humid environments, withstanding repeated machine washing, and resistant to various forms of physical damage. As a demonstration of potential application, textile-based EL devices were fabricated, which could display colored and pixelated patterns as well as dynamic images. The thermal lamination technology developed in this work can potentially enable people to DIY (do it yourself) fabricate light-emitting devices on clothing using daily tools, which could facilitate the widespread use of textile-based wearable displays.

Dendritic Quaternary-Encoded Oligourethanes for Data Encryption

The use of sequence-defined digital polymers for data storage and encryption has received increasing attention due to their precision structures similar to natural biomacromolecules (e.g., DNA) but increased stability. However, the rapid development of sequencing techniques raises the concern of information leakage. Herein, dendritic quaternary-encoded oligourethanes bearing a photoresponsive trigger, self-immolative backbones, and a mass spectrometry tag of PEG dendron have been developed for data encryption. Although the sequence information in linear analogs can be readily deciphered by mass spectrometry, sequencing of dendritic oligourethanes cannot be achieved by either primary MS or tandem MS/MS owing to the unique spatial conformation. Intriguingly, the fragmentation pathways of a quaternary dendrimer under MS/MS conditions can be converted to 2772-bit 2D matrices with ≈1.98×10⁸⁷ permutations, serving as high-strength encryption keys for highly reliable data encryption.