The popularity of humidity sensing for respiratory analysis of patients is gradually increasing because of its portability and cost-effectiveness. However, current flexible humidity sensors are mainly made of polymer films, whose poor hygroscopicity and breathability reduce their sensitivity and comfort. In this study, a highly sensitive humidity sensor was developed using non-woven fabric (NWF) coated with graphene oxide (GO). Bovine serum albumin was used to improve the adsorption of GO onto the NWF, and its effect on sensitivity was investigated by adjusting its concentration. Highhumidity sensitivity was experimentally validated by testing different relative humidity levels, and its fast response and excellent feasibility under diverse breathing conditions were verified by successful monitoring of fast and deep breathing, differentiating nose and mouth breathing, and even identifying simple spoken words. This study developed a breathable and skin-friendly humidity sensor based on GO/NWF, which is a promising device for human healthcare.

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Frost accretion on surfaces may cause severe problems and the high-efficiency defrosting methods are still urgently needed in many application fields like heat transfer, optical and electric power system, etc. In this study, a nano-needle superhydrophobic surface is prepared and the frosting/defrosting experiments are conducted on it. Three steps are found in the defrosting process: melting frost shrinking and splitting, instantaneous self-triggered deforming followed by deformation-induced movements (namely, in-situ shaking, rotating, rolling, and self-jumping). The self-jumping performance of the melting frost is extremely fascinating and worth studying due to its capability of evidently shortening the defrosting process and reducing (even avoiding) residual droplets after defrosting. The study on the melting frost self-jumping phenomena demonstrates that the kinetic energy transformed from instantaneous superficial area change in self-triggered deforming step is the intrinsic reason for various melting frost self-propelled movements, and when the transformed energy reaches a certain amount, the self-jumping phenomena occur. And some facilitating conditions for melting frost self-jumping phenomena are also discussed. This work will provide an efficient way for defrosting or an inspiration for further research on defrosting.

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Thermal barrier coating (TBC) is an essential requirement of a modern gas turbine engine. The TBC failure is the delamination and spallation. The failure mechanism is interfacial expansion mismatch and oxidation of bond coat (BC). The oxidation damage under high temperature results in the reduction of interfacial adhesion. The interfacial fracture toughness is an important property to analyze the TBC failure. Using the simple tensile test, pushout test method and three-point or four-point-bending test and so on, the interfacial fracture toughness of ceramic top coat/BC has been researched in the past. However, the fracture toughness of the BC/substrate due to the Al depletion was very few studied. In this study, a NiCrAlY bond coat by air plasma spray (APS) was deposited. The substrate is directionally solidified superalloy (DZ40M). The Young's modulus of bond coat was obtained by the nanoindentation and average Young's modulus of bond coat is 66.9 GPa. Isothermal oxidation was performed at 1,050 • C for 100 h. Using the HXZ-1000 micro-hardness equipment and fracture mechanics approach, the five different times was chosen to test the hardness and the crack length, and then the fracture toughness was obtained. While the oxidation exposure time increased at 1,050 • C, the hardness of the substrate close to the bond coat decreased with the increase of the bond coat in hardness. Meanwhile, the interfacial fracture toughness of the bond coat-substrate decreased because of the Al depletion.