In this study, a new electrochemical machining(ECM) method was proposed by using porous solids to absorb the electrolyte and limit the contact area between the workpiece and the electrolyte. Due to the porous structures inside the porous solids, electrolyte solutions can be absorbed and retained easily. The electrolyte absorbed by porous solids can form the current path from the workpiece to the tool electrode. Since the workpiece is not immersed in the electrolyte, only the area in contact with the porous solids will be machined, while the other areas of the workpiece are not affected at all. In this way, the machining accuracy of ECM can be increased significantly.

This study aims at investigating the process of machining alkali-free thin glass using a picosecond pulsed laser. A 2-step irradiation method, involving both processes of property modification and machining improvement, is proposed using different laser wavelengths. An IR laser was first focused on the glass substrate for enhancing the light-absorption capability of the glass and a subsequent UV laser was engaged in machining the modified area for drilling through holes. The characteristics of laser modification and laser drilling were examined through varying laser processing parameters of irradiation and machining. The ultimate goal is to use lower UV power to complete laser drilling on alkali-free glass and obtain higher quality of drilling.

Injection molded direct joining (IMDJ) is a promising metal–plastic direct joining method, which first treats the metal surface and then injects melted plastic onto the surface via injection insert molding. The mechanical interlocking is widely accepted as one of the joining mechanisms. On the other hand, the existence of the chemical interaction, which can form between polar groups/molecules on the metal surface and functional groups in the plastic, is still unclear. Thus, the objective of this study is to verify whether the chemical interaction takes effect on the joining between metal and plastic. IR spectrums are usually used to characterize the chemical interaction. However, the general IR system is limited because it does not reach nanoscale spatial resolution. Here, we solved this limitation by applying AFM-IR. Aluminum plates with different surface chemical conditions were prepared and then joined with polyamide 6 (PA6) via IMDJ. We then characterized the joint interface with AFM-IR. The IR spectrum change showed that the hydrogen bonding formed between -OH on the aluminum surface and -CONH in PA6. The results showed that the hydrogen bonding existed, and AFM-IR was able to characterize IR spectrums at the metal–plastic interface in a nanoscale.

In this paper, we set up an experimental setup, which has a heterodyne interferometer, a phase meter, and a piezoelectric (PZT) stage for obtaining 10-pm-order mechanical displacement measurements. To suppress residual errors in the measurements, the interferometer combined with the PZT stage is placed in a vacuum chamber at low pressure. Next, the chamber, the heterodyne light source, and other optics are located on an antivibration that is enclosed by a sealed room. The phase meter is based on a phase-locked loop (PLL) [1] and programmed on a field-programmable gate array (FPGA) module. Mechanical displacements with a resolution of 10 pm order are implemented at 〜230 Pa and measured by the interferometer combined with the phase meter. The experimental result shows the combined system obtains a mechanical step displacement of 11 pm and a displacement noise floor of <0.2 pm/sqrt(Hz). The setup, the signal processing of the phase meter, experiments, and results are discussed. Reference [1] T.-D. Nguyen, Q.-A. Duong, M. Higuchi, T.-T. Vu, D. Wei, and M. Aketagawa, “19-picometer mechanical step displacement measurement using heterodyne interferometer with phase-locked loop and piezoelectric driving flexure-stage,” Sens. Actuators A Phys. 304, 111880 (2020).

Food safety is the major factor affecting public health though foodborne illness every day throughout the food supply chain. Many of us familiar to check the use by dates on the food packaging labels. Many people throw away the food by those dates even the packaged food is still safe to eat. To over large amount of food wastage, the development of intelligent packaging system fast-tracked in recent years. Hence, in this research we aim to develop an ultrathin calorimetric nanosheet sensors to embed in the food packaging material, that can change its colour while absorbing the food spoilage biomarkers such as ammonia. The poly-L-lactic acid and polyvinyl alcohol mixed with anthocyanin based thin nanosheet is prepared and tested successfully in detection of ammonia in meat packages. The thickness of the nanosheet is around few hundreds of nanometers and it can be stacked with packaging labels. Using color indicators one can easily identify the freshness of the food by naked eye. We are progressing in enhancing the colour change as well as checking its long term stability.