Since the discovery of graphene, researchers have searched for scalable and cost-effective ways to use its special electrical, mechanical, and thermal properties. Traditional two-dimensional graphene performs well, but it has problems. The sheets restack. Binders are required. The fabrication steps are complex and often need chemicals or high temperatures. These issues reduce its usefulness in triboelectric nanogenerators (TENG). Laser induced graphene (LIG), introduced in 2014 by direct laser writing on polyimide, offers a strong alternative. It allows fast and simple production of porous and conductive three-dimensional graphene structures. LIG keeps the key benefits of graphene, such as high conductivity, large surface area, and mechanical flexibility. It also allows easy control of the structure by adjusting laser settings and can be integrated with many substrates. These strengths have boosted the development of LIG based TENGs for wearable devices, environmental monitoring, and biomedical uses. This review outlines the growth of LIG research, fabrication methods, design strategies, and various potential applications in LIG enabled TENGs. It also discusses current challenges and future opportunities, showing the rising importance of LIG as a sustainable and efficient electrode material for triboelectric energy harvesting.
A new synthesis route for three-dimensional cage-type mesoporous carbon was developed using phosphoric acid (H3PO4) as a dual-function catalyst. H3PO4 promoted dehydration of sucrose as an acid catalyst and enabled systematic tuning of both cage size and inter-cage window size by forming a polyphosphoric acid layer at the silica–carbon interface. By increasing the H3PO4/sucrose molar ratio, uniform mesopore diameters expanded from 13.1 to 16.6 nm and window sizes from 7.3 to 9.8 nm at a pyrolysis temperature of 900 °C. In lithium-sulfur (Li–S) batteries, enlarged windows significantly improved lithium polysulfides (LiPSs) transport and rate capability. Notably, a well-preserved, template-replicated mesoporous framework was achieved even at an exceptionally low carbonization temperature of 400 °C, whereas sulfuric-acid-derived samples exhibited poorly developed porosity and structural collapse under identical conditions. The cage-type mesoporous carbon synthesized at 400 °C retained abundant oxygen- and phosphorus-containing polar functional groups, as confirmed by elemental analysis and XPS, leading to markedly enhanced LiPSs adsorption. Accordingly, the highly functionalized mesoporous carbon delivered superior cycling stability, maintaining 82.3
In shape-from-focus, the focus measure operator (FM) determines the accuracy of the depth map of a reconstructed object. Typically, before applying FM, vector-valued (color) images are converted into gray-scale for simplicity. However, this conversion prevents the FM from incorporating focus information from all color channels, leading to inaccuracies in the depth map. To overcome this limitation, we propose a dual-stage focus measure. The first stage involves converting the vector-valued image volume into a scalar-valued image volume using a unique method that facilitates the application of FM. This conversion is achieved through vector operations that compute a scaled norm from the difference vectors, with a scaling factor adjusted according to the variations in these norms. In the second stage, the focus measure is applied using the Directional Ring Difference Filter (DRDF) in different directions to obtain directional focus volumes, which are then aggregated using a weighted approach to compute a unified focus volume from which the depth map is ultimately extracted. Our extensive evaluation, conducted on over 1200 scenes comprising more than 17,000 images, demonstrated the superiority of our method. It outperformed 18 renowned techniques, achieving around 6.7 percent lower RMSE compared to the second best method on the HCI14 dataset. The official implementation of our method is publicly available and can be found at: https://github.com/khurramashfaq/dual-stage-fm-sff.
Hybrid additive manufacturing (HAM) is characterized by process variability and low reproducibility, necessitating reliable real-time monitoring of tool condition during machining. In this study, tool condition monitoring was performed using weak acoustic emission (AE) signals acquired from a sensor remotely mounted on the spindle housing. Experiments were conducted using 18Ni-300 maraging steel fabricated via laser powder bed fusion. To detect tool condition changes under low signal-to-noise ratio (SNR) conditions caused by signal attenuation and rotational noise, a normalized RMS ratio index—defined as the ratio of hit RMS to pre-trigger RMS—was introduced, together with a threshold-based RMS ratio Count method. Based on experimental data collected from manufacturing cycles, the RMS ratio Count exhibited a pronounced increase at Cycle 9, which coincided with the occurrence of tool breakage. In particular, the number of events exceeding a threshold of 4 increased sharply at the failure cycle. For example, the RMS ratio Count (> 4) increased from 13 to 20 at the breakage cycle. Furthermore, surface roughness measurements revealed a significant degradation after tool breakage, with the Sa value increasing from 1.37 μm to 2.23 μm (approximately 62.4
CFRE composites are widely applied to relatively simple sheet forms; however, when applied to actual products in complex forms, a finishing process is frequently required in conjunction with machining. Nevertheless, studies on the machinability of the CFRE composite in manufacturing actual products are still relatively rare. This study analyzed the machinability of CFRE composites in drilling and milling processes. The cutting processes involving drilling and milling methods were performed at various machining parameters. Key drilling findings indicate that flat endmills provide superior entry and bottom surfaces compared to twist drills. Increasing the number of cutting edges from two to four flutes enhances cutting ability, although all tools generate delamination at the exit of the through hole. While tool type did not significantly affect side-surface texture, optimal dimensional accuracy in 0.007 mm was achieved using a 4-flute flat-end mill with a cutting speed of 50 m/min and a feed rate of 80 mm/min. In side milling, surface characteristics were identical for both up-milling and down-milling; however, the down-milling method is recommended for parallel cutting to minimize burrs. For pocket milling, burrs predominantly formed on the lateral margin. This burr formation was intensified by elevated feed rates, indicating that lower feed rates yield better surface quality.
