Surface-enhanced Raman scattering (SERS) is a technique that can deliver label-free, real-time, and multiplex detection of target molecules. However, the development of this potential tool has been impeded by an obstacle: reliability. Because SERS detection relies on the very localized (< 10 nm) hot spot, severe intensity fluctuation occurs as the molecule thermally diffuses in and out of the tiny spot, making it difficult to quantify the information of analytes. Here, we address the problem by greatly expanding the effective area of a hot spot. The breakthrough is realized by a few layers of conformally nanostructured InGaN, which introduce wafer-scale charge coupling at the molecule/metal/semiconductor interface. These additional coupling channels interconnect plasmonic nanojunctions, rendering the SERS-active surface spreading over 1200 μm2 in Raman mapping. The result allows us to capture trace molecules with increased chances and stabilized signals, paving a way for SERS to enter real-life applications.

This paper used finite element analysis of metal forming to study the forging process and die design of aluminum alloy brake parts. According to the process parameters and die design, the brake parts were forged by experiment. First, the die design is based on the product size and considering parting line, draft angle, forging tolerance, shrinkage and scrap. Secondly, the finite element analysis of metal forming is used to simulate the forging process of aluminum alloy brake parts. Finally, the aluminum alloy brake levers with dimensional accuracy and surface hardness were forged.

Bipolar plate is the key component of proton exchange membrane fuel cells. Due to the factors of rapid and mass production, the stamping process is selected to manufacture the bipolar metal plates. First, the stress-strain curve is performed by universal material testing machine.The stress-strain curve is necessary for bipolar plate stamping simultion. The maximum forging load and effective stress distribution of bipolar plate stamping are determined by finite element analysis. Finally, the effect of the traditional crank stamping on the flatness and section thickness of stainless steel bipolar plate are observed by experiments.