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Compared with the lever-type amplifier, the rhombus-type amplifier has attracted more attention by virtue of large displacement amplification ratio, compact structure, and linear output displacement. In this paper, a novel electromagnetic force balance sensor (EFBS) based on the rhombus-type amplifier is presented to measure the mass with high precision. First, the structure and operating principle of the EFBS are described, and the requirements for the design and manufacture of the amplifier are put forward. Then, the analytical models of the two-stage rhombus-type amplifier are given out, and two guiding mechanisms are analyzed and modeled. Furthermore, the validity of the established model is verified by finite element analysis (FEA). Thanks to the theoretical guidance, an electromagnetic force balance sensor based on the two-stage rhombus-type amplifier and double parallelogram flexure mechanism is designed and tested. The experimental results demonstrate that the developed EFBS can measure the mass of the objects with high precision, and also verifies the correctness of the analytical model. This provides a new concept for the structural design of the EFBS.

In this paper, CeO2 with a pore size of 2–4 nm was synthesized by hydrothermal method. The CeO2 modified graphene-supported Pt catalyst was prepared by the microwave-assisted ethylene glycol reduction chloroplatinic acid method, and the effect of the addition of CeO2 prepared by different hydrothermal reaction time on the catalytic performance of Pt-based catalysts was investigated. The microstructures of CeO2 and catalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), specific surface area and pore size analyzer (BET), scanning electron microscopy (SEM) and electron spectroscopy (EDAX), transmission electron microscopy (TEM), and the catalysts electrochemical performance was tested by electrochemical workstation. The results show that the catalytic performance of the four catalysts with CeO2 is better than that of the catalyst without CeO2. Adding CeO2 with a specific surface area of 120.15 m2/g prepared by hydrothermal reaction time of 39 h to Pt/C synthesis catalyst, its electrocatalytic performance, stability and resistance to poisoning are the best. The electrochemical active surface area is 102.83 m2/g, the peak current density of ethanol oxidation is 757.17 A/g and steady-state current density of 1100 s is 108.17 A/g which shows the lowest activation energy for ethanol oxidation reaction. When the cyclic voltammogram is scanned for 500 cycles, the oxidation peak current density retention rate is 87.74%.