To accurately assess mechanical properties of micro- and nano-sized specimens, a reliable material testing system is indispensable. However, due to small sizes of these test specimens, in-situ measurement of their mechanical behavior necessitates installing the tester within high-magnification microscopes such as SEM. Traditionally, researchers have used wired methods by placing the tester inside the SEM chamber and connecting it to an external controller via electrical feedthrough. Unfortunately, this approach is cumbersome. In addition, it limits its compatibility with other SEMs. In this study, we developed a compact controller capable of driving 3-axis piezoelectric actuators with nanometer-level displacement control resolution via Bluetooth communication. This innovative setup enables wireless control and data acquisition from outside the closed confines of an SEM chamber. To validate the versatility of our tester, we conducted both a nanoindentation test on a fused silica specimen using a Berkovich indenter in a wired configuration and a copper micropillar compression test wirelessly using a flat punch indenter within an SEM. By installing this tester in various measurement systems, researchers could observe deformation patterns in real time, making it a valuable tool for investigating deformation mechanisms of diverse micro- and nano-sized specimens.

With the increasing use of portable devices, the safety and efficiency of wireless chargers have become significant concerns. Wireless chargers can cause battery damage, deformation, and failure of the charging module due to the high temperatures generated during the charging process. Thus, the importance of thermal management has been increasingly emphasized. In this study, we experimentally confirmed that cooling performance was improved by applying phase change material (PCM) to the heat-generating parts of the wireless charger. The cooling performance of the PCM was analyzed using Ansys Fluent, the component temperature was measured with an infrared camera, and 3D thermal deformation was measured with a DIC measurement device. Electromagnetic field, thermal, fluid, and structural coupled analyses were performed to investigate the impact of thermal deformation caused by wireless charging. The results showed that the temperature and deformation error was within 3% of the coupled analysis results, and the proposed electromagneticthermal-fluid-structural coupled analysis enabled more accurate simulation prediction of the physical coupling process inside the wireless charger.