To guarantee the normal operation of next generation portable electronics and wearable devices, together with avoiding electromagnetic wave pollution, it is urgent to find a material possessing flexibility, ultrahigh conductive, and superb electromagnetic interference shielding effectiveness (EMI SE) simultaneously. In this work, inspired by a building bricks toy with the interlock system, we design and fabricate a copper/large flake size graphene (Cu/LG) composite thin film (≈8.8 μm) in the light of high temperature annealing of a large flake size graphene oxide film followed by magnetron sputtering of copper. The obtained Cu/LG thin-film shows ultrahigh thermal conductivity of over 1932.73 (±63.07) W m K and excellent electrical conductivity of 5.88 (±0.29) × 10 S m . Significantly, it also exhibits a remarkably high EMI SE of over 52 dB at the frequency of 1-18 GHz. The largest EMI SE value of 63.29 dB, accorded at 1 GHz, is enough to obstruct and absorb 99.99995% of incident radiation. To the best of knowledge, this is the highest EMI SE performance reported so far in such thin thickness of graphene-based materials. These outstanding properties make Cu/LG film a promising alternative building block for power electronics, microprocessors, and flexible electronics.

No abstract

Different from usually-used bulk magnetostrictive materials, magnetostrictive TbDyFe thin films were firstly proposed as sensing materials for fiber-optic magnetic field sensing characterization. By magnetron sputtering process, TbDyFe thin films were deposited on etched side circle of a fiber Bragg Grating (FBG) as sensing element. There exists more than 45pm change of FBG wavelength when magnet field increase up to 50 mT. The response to magnetic field is reversible, and could be applicable for magnetic and current sensing.

No abstract

No abstract

WO3-Pd composite films were deposited on the side-face of side-polished fiber Bragg grating as sensing elements by magnetron sputtering process. XRD result indicates that the WO3-Pd composite films are mainly amorphous. Compared to standard FBG coated with same hydrogen sensitive film, side-polished FBG significantly increase the sensor's sensitivity. When hydrogen concentrations are 4% and 8% in volume percentage, maximum wavelength shifts of side-polished FBG are 25 and 55 pm respectively. The experimental results show the sensor's hydrogen response is reversible, and side-polished FBG hydrogen sensor has great potential in hydrogen's measurement.

Since fiber-matrix interface strength is critical to properties of carbon fiber-reinforced composites, measurement and analysis of interface strength are crucial steps in tailored design of composites. In the present work, the single fiber push-out test and the short-beam shear test were applied to measure the fiber-matrix interface strength in uni-directionally and two-directionally carbon fiber-reinforced phenolic resin matrix composites. The technical difficulties in processing the specimen and in realizing the fiber push-out were also discussed and clarified. For obtaining the successful test, typically, the thickness of the specimen should be smaller than 100 mm. During the fiber push-out, the de-bonding and fiber sliding at the interface were analyzed from the load-displacement curve features. The results indicated that both methods could be applied to determine the interface strength. The single fiber push-out and the short-beam shear tests resulted in a similar phenomenon in regard to the interface strength of uni-directionally and two-directionally carbon fiber-reinforced phenolic resin matrix composites, but expressed different values. The low interface strength measured from the short-beam shear test could be associated with multiple interlaminar shear failures. Furthermore, it was found that the interface strength of uni-directionally carbon fiber-reinforced phenolic resin matrix composites is somewhat higher than that of two-directionally carbon fiber-reinforced phenolic resin matrix composites. The difference in the interface strength could be attributed to the thermally induced residual stresses caused by the coefficient of thermal expansion mismatch of fiber and matrix. The approaches applied in the current work can be used for the evaluation of the interface strength of carbon fiber-reinforced phenolic resin matrix composites with different fiber-matrix bonding properties.

No abstract