No abstract

A new type of space crawling robot was proposed for spacecraft maintenance missions and a nanoscale microarray structure was designed as the robot foot structure. In this study, a carbon nanotube array structure was adopted as the adhered nanoscale microarray structure of the robot foot. A theoretical model of the carbon nanotube structure was established, and the influence of the structural parameters of the carbon nanotube array on its adhesion characteristics was analyzed. A force model of carbon nanotube arrays on different roughness surfaces and under different preloads was established using the discrete element software, EDEM. A simulation of the desorption process of the carbon nanotube array structure in the normal and tangential directions was conducted. The adhesion characteristics of the carbon nanotube structure were analyzed. On this basis, the carbon nanotube microarray structure was fabricated using chemical vapor deposition, and a force test system was established on the platform of a scanning electron microscope to test the adhesion force of the carbon nanotube array in a vacuum environment. The influence of preloading and roughness on the adhesion characteristics of the carbon nanotube array structure was analyzed.

A novel electrochemical method was proposed for detection of hydrogen peroxide (H2O2) based on electrochemical reduction of graphene oxide (GO) modified glassy carbon electrode (GCE). The electrochemically reduced graphene oxide (RGO) was characterized using cyclic voltammetry (CV). Under the optimized conditions, the RGO modified GCE showed much wide linear range for H2O2 from 2.0 to 600 M with the detection limit of 0.67 M (S/N = 3). The proposed method is simple, low-cost and convenient and will be a promising alternative for H2O2 sensing.

An in situ thermal oxidation strategy was proposed for synthesizing different SnO2 nanostructures, using our homemade SnS2 nanoplates as a precursor. The characterization results from X-ray diffraction, energy dispersive X-ray spectroscopy, and field emission scanning electron microscope revealed that the heating temperature played an important role in the microstructure and composition of the resultant products. By heating the SnS2 nanoplates in air at 400, 600 and 800 °C for 5 h, nanoplates, a mixture of nanoplates and nanoparticles, and nanoparticles of SnO2 were synthesized, respectively. The residual S was about 2.2 mol % in the product synthesized at 400 °C, while no residual S was detected in the products synthesized at 600 and 800 °C.