Skin-mountable microelectronics are garnering substantial interest for various promising applications including human-machine interfaces, biointegrated devices, and personalized medicine. However, it remains a critical challenge to develop e-skins to mimic the human somatosensory system in full working range. Here, we present a multifunctional e-skin system with a heterostructured configuration that couples vinyl-hybrid-silica nanoparticle (VSNP)–modified polyacrylamide (PAM) hydrogel with two-dimensional (2D) MXene through nano-bridging layers of polypyrrole nanowires (PpyNWs) at the interfaces, featuring high toughness and low hysteresis, in tandem with controlled crack generation and distribution. The multidimensional configurations endow the e-skin with an extraordinary working range (2800%), ultrafast responsiveness (90 ms) and resilience (240 ms), good linearity (800%), tunable sensing mechanisms, and excellent reproducibility. In parallel, this e-skin platform is capable of detecting, quantifying, and remotely monitoring stretching motions in multiple dimensions, tactile pressure, proximity sensing, and variations in temperature and light, establishing a promising platform for next-generation smart flexible electronics.

It was numerically predicted that dissolved gas particles could enrich and adsorb at hydrophobic-liquid interfaces. Here we observe nucleation and growth of bright patches of ∼0.45 nm high on the graphite surface in pure water with frequency-modulation atomic force microscopy when the dissolved gas concentration is below the saturation level. The bright patches, suspected to be caused by adsorption of nitrogen molecules at the graphite-water interface, are composed of domains of a rowlike structure with the row separation of 4.2 ± 0.3 nm. The observation of this ordered adlayer might underline the gas segregation at various water interfaces.

The thermodynamic properties of gases have been understood primarily through phase diagrams of bulk gases. However, observations of gases confined in a nanometer space have posed a challenge to the principles of classical thermodynamics. Here, we investigated interfacial structures comprising either O 2 or N 2 between water and a hydrophobic solid surface by using advanced atomic force microscopy techniques. Ordered epitaxial layers and cap-shaped nanostructures were observed. In addition, pancake-shaped disordered layers that had grown on top of the epitaxial base layers were observed in oxygen-supersaturated water. We propose that hydrophobic solid surfaces provide low-chemical-potential sites at which gas molecules dissolved in water can be adsorbed. The structures are further stabilized by interfacial water. Here we show that gas molecules can agglomerate into a condensed form when confined in a sufficiently small space under ambient conditions. The crystalline solid surface may even induce a solid-gas state when the gas-substrate interaction is significantly stronger than the gas-gas interaction. The ordering and thermodynamic properties of the confined gases are determined primarily according to interfacial interactions.G ases exist throughout the universe and are essential in daily life as well as science and technology. Gases are generally defined as molecules that have boiling points below room temperature, such as the small nonpolar molecules N 2 , O 2 , He, and Xe. Gases are vapor under ambient conditions because van der Waals (VDW) interactions among gas molecules are much weaker than thermal energy. Condensing gas molecules into a liquid or solid state, based on the phase diagrams of bulk gases, requires high pressures or cryogenic techniques. However, numerous puzzling observations regarding gases confined in a small space have been reported. For example, gases have been observed to accumulate in a cap-shaped space on a nanometer scale at solid-water interfaces, mainly hydrophobic-water interfaces, under ambient conditions 1-13 . The cap-shaped structures are generally considered interfacial nanobubbles (INBs) that feature gas molecules in their vapor (gaseous) phase. However, their thermodynamic stability, nature, nucleation, and other properties and behaviors remain unclear. Theoretical prediction has indicated that gases inside a bubble of nanometer size should dissolve into the surrounding water in a short time 14 because of its high internal pressure, P in , which can be described using the Young-Laplace equation,where P 0 is the liquid pressure (approximately 1 atm in most laboratory conditions), C is the surface tension of the interface between liquid and gas, and r is the radius of the bubble (see Supplementary Note 1). Numerous atomic force microscopy (AFM) observations have shown that INBs are stable for hours or days [1][2][3][4][5][6][7][8][9][10][11][12] , which are at least 10-11 orders of magnitude longer than the theoretical lifetime estimated based on the Young-Laplace equation 9 ....

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Electrochemical deposition has emerged as a novel approach to fabricate metal–organic framework (MOF) films. Here, for the first time, an aqueously cathodic deposition (ACD) approach is developed to fabricate ZIF‐8 type of MOF membranes without addition of any supporting electrolyte or modulator. The fabrication process uses 100% water as the sole solvent and a low‐defect density membrane is obtained in only 60 min under room temperature without any pre‐synthesis treatment. The membrane exhibits superior performance in C3H6/C3H8 separation with 182 GPU C3H6 permeance and 142 selectivity, making it sit at the upper bound of permeance versus selectivity graph, outperforming majority of the published data up to 2019. Notably, this approach uses an extremely low current density (0.13 mA cm−2) operated under an ultrafacile apparatus set‐up, enabling an attractive way for environmentally friendly, energy efficient, and easily scalable MOF membrane fabrications. This work demonstrates a great potential of aqueously electrochemical deposition of MOF membrane in the future research.