Comparison of Bivalent and Monovalent mRNA Vaccine Boosters

In this cohort study conducted in Hong Kong where both bivalent and monovalent formulations of BNT162b2 were available, there were no significant differences in the mortality or hospitalization between those who received bivalent and monovalent mRNA as second boosters. Bivalent and monovalent mRNA boosters appear equally protective against clinical outcomes.

Thermal and Moisture Managing E-Textiles Enabled by Janus Hierarchical Gradient Honeycombs

Moisture and thermal comfort are critical for long-term wear. In recent years, there has been rapidly growing attention on the importance of the comfortability in wearable electronic textiles (e-textiles), particularly in fields such as health monitoring, sports training, medical diagnosis and treatment, where long-term comfort is crucial. Nonetheless, simultaneously regulating thermal and moisture comfort for the human body without compromising electronic performance remains a significant challenge to date. Herein, a thermal and moisture managing e-textile (TMME-textile) that integrates unidirectional water transport and daytime radiative cooling properties with highly sensitive sensing performance is developed. The TMME-textile is made by patterning sensing electrodes on rationally designed Janus hierarchical gradient honeycombs that offer wetting gradient and optical management. The TMME-textile can unidirectionally pump excessive sweat, providing a dry and comfortable microenvironment for users. Moreover, it possesses high solar reflectivity (98.3%) and mid-infrared emissivity (89.2%), which reduce skin temperature by ≈7.0 °C under a solar intensity of 1 kW m-2 . The TMME-textile-based strain sensor displays high sensitivity (0.1749 kPa-1 ) and rapid response rate (170 ms), effectively enabling smooth long-term monitoring, especially during high-intensity outdoor sports where thermal and moisture stresses are prominent challenges to conventional e-textiles.

Wet-Adaptive Electronic Skin

Skin electronics provides remarkable opportunities for non-invasive and long-term monitoring of a wide variety of biophysical and physiological signals that are closely related to health, medicine, and human-machine interactions. Nevertheless, conventional skin electronics fabricated on elastic thin films are difficult to adapt to the wet microenvironments of the skin: Elastic thin films are non-permeable, which block the skin perspiration; Elastic thin films are difficult to adhere to wet skin; Most skin electronics are difficult to work underwater. Here, a Wet-Adaptive Electronic Skin (WADE-skin) is reported, which consists of a next-to-skin wet-adhesive fibrous layer, a next-to-air waterproof fibrous layer, and a stretchable and permeable liquid metal electrode layer. While the electronic functionality is determined by the electrode design, this WADE-skin simultaneously offers superb stretchability, wet adhesion, permeability, biocompatibility, and waterproof property. The WADE-skin can rapidly adhere to human skin after contact for a few seconds and stably maintain the adhesion over weeks even under wet conditions, without showing any negative effect to the skin health. The use of WADE-skin is demonstrated for the stable recording of electrocardiogram during intensive sweating as well as underwater activities, and as the strain sensor for the underwater operation of virtual reality-mediated human-machine interactions.

A monolithically integrated in-textile wristband for wireless epidermal biosensing

Textile bioelectronics that allow comfortable epidermal contact hold great promise in noninvasive biosensing. However, their applications are limited mainly because of the large intrinsic electrical resistance and low compatibility for electronics integration. We report an integrated wristband that consists of multifunctional modules in a single piece of textile to realize wireless epidermal biosensing. The in-textile metallic patterning and reliable interconnect encapsulation contribute to the excellent electrical conductivity, mechanical robustness, and waterproofness that are competitive with conventional flexible devices. Moreover, the well-maintained porous textile architectures deliver air permeability of 79 mm s-1 and moisture permeability of 270 g m-2 day-1, which are more than one order of magnitude higher than medical tapes, thus ensuring superior wearing comfort. The integrated in-textile wristband performed continuous sweat potassium monitoring in the range of 0.3 to 40 mM with long-term stability, demonstrating its great potential for wearable fitness monitoring and point-of-care testing.

Stretchable and Self-Healable Fiber-Shaped Conductors Suitable for Harsh Environments

Fiber-shaped conductors with high electrical conductivity, stretchability, and durability have attracted increasing attention due to their potential for integration into arbitrary wearable forms. However, these fiber conductors still suffer from low reliability and short life span, particularly in harsh environments. Herein, a conductive, environment-tolerant, stretchable, and healable fiber conductor (CESH), which consists of a self-healable and stretchable organohydrogel fiber core, a conductive and buckled silver nanowire coating, and a self-healable and waterproof protective sheath, is reported. Such a multilayer core-sheath design not only offers high stretchability (≈2400%), high electrical conductivity (1.0 × 106 S m-1 ), outstanding self-healing ability and durability, but also possesses unprecedented tolerance in harsh environments including wide working temperature (-60-20 °C), arid (≈10 % RH (RH: room humidity)), and underwater conditions. As proof-of-concept demonstrations, CESHs are integrated into various wearable formats as interconnectors to steadily perform the electric function under different mechanical deformations and harsh conditions. Such a new type of multifunctional fiber conductors can bridge the gap in stretchable and self-healing fiber technologies by providing ultrastable electrical conductance and excellent environmental tolerance, which can greatly expand the range of applications for fiber conductors.

Wafer-patterned, permeable, and stretchable liquid metal microelectrodes for implantable bioelectronics with chronic biocompatibility

Implantable bioelectronics provide unprecedented opportunities for real-time and continuous monitoring of physiological signals of living bodies. Most bioelectronics adopt thin-film substrates such as polyimide and polydimethylsiloxane that exhibit high levels of flexibility and stretchability. However, the low permeability and relatively high modulus of these thin films hamper the long-term biocompatibility. In contrast, devices fabricated on porous substrates show the advantages of high permeability but suffer from low patterning density. Here, we report a wafer-scale patternable strategy for the high-resolution fabrication of supersoft, stretchable, and permeable liquid metal microelectrodes (μLMEs). We demonstrate 2-μm patterning capability, or an ultrahigh density of ~75,500 electrodes/cm2, of μLME arrays on a wafer-size (diameter, 100 mm) elastic fiber mat by photolithography. We implant the μLME array as a neural interface for high spatiotemporal mapping and intervention of electrocorticography signals of living rats. The implanted μLMEs have chronic biocompatibility over a period of eight months.