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Porous V2O5/TiO2 nanoheterostructure films with different atomic ratios of Ti/V (4:1, 2:1, 1:1, and 1:2) were synthesized by a sparking method for the first time. The sparking method, which is a simple and cost-effective process, can synthesize highly porous and composite films in one step. Field-emission scanning electron microscope (FE-SEM) images revealed the porosity morphology of all prepared samples. V2O5/TiO2 nanoheterostructure films were confirmed by Raman spectroscopy, high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). The secondary particle size and band gap of the samples were highly correlated to the V2O5 proportion, resulting in enhanced visible-light absorbance. V2O5/TiO2 nanoheterostructure films at an atomic ratio of 1:1 showed the highest photocatalytic performance, which improved the degradation rate up to 24% compared to pure TiO2 film. It is believed that the formed nanoheterostructure and greater portion of V4+ ions are reflected by this ratio.

Flexible, stretchable and wearable sensors are needed for the human motion detection. Here, a highly stretchable and sensitive strain sensor is fabricated based on the coating of nanographene platelets on natural rubber by simple dry coating process. The gauge factors are adjustable in the ranges of 0.78-52.53 depended on the preparation conditions and strain state. The sensors showed a high stretchability up to 750% and high durability of 1500 stretching-releasing cycles. The stretchable strain sensors are capable of detecting a bending fingers and the pulse of radial artery on the wrist. In addition, a smart glove made form five independent strain sensors was created. The data of the glove finger motions are used to control an avatar robotic hand.

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Copper–iron (Cu–Fe) oxide composite films were successfully deposited on quartz substrate by a facile sparking process. The nanoparticles were deposited on the substrate after sparking off the Fe and Cu tips with different ratios and were then annealed at different temperatures. The network particles were observed after annealing the film at 700 °C. Meanwhile, XRD, XPS and SAED patterns of the annealed films at 700 °C consisted of a mixed phase of CuO, γ-Fe2O3, CuFe2O4 and CuFe2O. The film with the lowest energy band gap (Eg) of 2.56 eV was observed after annealing at 700 °C. Interestingly, the optimum ratio and annealing temperature show the photocatalytic activity under visible light higher than 20% and 30% compare with the annealed TiO2 at 500 and 700 °C, respectively. This is a novel photocatalyst which can be replaced TiO2 for photocatalytic applications in the future.

Stretchable and compressible strain sensors play an essential role in various fields with uses ranging from automotive components to medical devices. This study reports on the fabrication and characteristics of stretchable strain and pressure sensors constructed using a carbon nanotube and graphene composite. The sensors were used for gait analysis, an important step in the diagnosis and management of movement disorders. The stretchable and compressible strain sensors were used to measure peak knee sagittal angles and forces under the feet when walking. Gait analysis is usually performed within a laboratory. However, in this research we propose a shift to gait assessments conducted via long-term daily monitoring using wearable devices.

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In this study, the authors researched the preparations of superhydrophilic/superhydrophobic surfaces on commercial cup stock polyethylene coated papers by using sparked aluminum nanoparticles deposited on substrates through a sparking process. In this stage, the surface was porous and showed superhydrophilic properties. The samples were then annealed in air at various temperatures and some transformed to superhydrophobicity. It is well known that a suitable roughness in combination with low surface energy has been required to obtain superhydrophobic surfaces. Therefore, it is believed that during annealing process, when polyethylene is diffused from the substrate through the nanoparticle films and the superhydrophobic characteristics were created. The scanning electron microscope images showed that the film surfaces had a fluffy structure for both the as‐deposited and the annealed samples. However, the atomic force microscopy phase images showed completely different surface properties. Moreover, the X‐ray photoelectron spectroscopy spectra showed different surface chemical compositions. The experimental results revealed that the working temperature to produce superhydrophobic surfaces depended on the sparked film thickness. Furthermore, in order to prove the assumption explained above, glass and poly (methyl methacrylate) were also used as substrates.