A bifunctional effect of laser-induced aligned lithiophilic microchannels and in situ formed LiF-enriched SEI on lithium deposition is proposed by using fs laser on the MXene membrane. Stable Li plating/stripping is achieved at 20 mA cm−2 in an asymmetric cell.
Laser-induced periodic surface structures (LIPSS) have become an important avenue towards surface nanopatterning and certain device applications due to their subwavelength feature size and versatility with different materials. However, the uncontrollable non-uniformity in achievable nanostructures presents a limit towards its practical application. Here, a robust approach is proposed to obtain controllable nanostructures with long-range order based on a new insight into one of the electromagnetic origins of nonuniformity of LIPSS, namely a half-periodic mismatched optical enhancement (h-MOE) effect. The h-MOE effect originates from the interference enhancement of surface plasmon polaritons (SPPs) located between tips of every two adjacent ripples in laser scanning process. It is found that LIPSS can be self-aligned and highly controllable if the h-MOE effect is elaborately modulated through designed laser scanning strategies especially sequential scanning paths. The new laser nanopatterning approach based on h-MOE demonstrates controllable patterning ability to theoretically infinitely large-area super-straight gratings, orientation-controllable gratings, and half-periodic mismatched nanohole arrays.
In this paper, the state of art of ultrasonicassisted machining technologies used for fabrication of micro/nano-textured surfaces is reviewed. Diamond machining is the most widely used method in industry for manufacturing precision parts. For fabrication of fine structures on surfaces, conventional diamond machining methods are competitive by considering the precision of structures, but have limitations at machinable structures and machining efficiency, which have been proved to be partly solved by the integration of ultrasonic vibration motion. In this paper, existing ultrasonic-assisted machining methods for fabricating fine surface structures are reviewed and classified, and a rotary ultrasonic texturing (RUT) technology is mainly introduced by presenting the construction of vibration spindles, the texturing principles, and the applications of textured surfaces. Some new ideas and experimental results are presented. Finally, the challenges in using the RUT method to fabricate micro/ nano-textured surfaces are discussed with respect to texturing strategies, machinable structures, and tool wear.
Liquid-assisted laser ablation has the advantage of relieving thermal effects of common laser ablation processes, whereas the light scattering and shielding effects by laser-induced cavitation bubbles, suspended debris, and turbulent liquid flow generally deteriorate laser beam transmission stability, leading to low energy efficiency and poor surface quality. Here, we report that a continuous and directional high-speed microjet will form in the laser ablation zone if laser-induced primary cavitation bubbles asymmetrically collapse sequentially near the air-liquid interface under a critical thin liquid layer. The laser-induced microjet can instantaneously and directionally remove secondary bubbles and ablation debris around the laser ablation region, and thus a very stable material removal process can be obtained. The shadowgraphs of high-speed camera reveal that the average speed of laser-induced continuous microjet can be as high as 1.1 m/s in its initial 500 μm displacement. The coupling effect of laser ablation, mechanical impact along with the collapse of cavitation bubbles and flushing of high-speed microjet helps achieve a high material removal rate and significantly improved surface quality. We name this uncovered liquid-assisted laser ablation process as laser-induced microjet-assisted ablation (LIMJAA) based on its unique characteristics. High-quality microgrooves with a large depth-to-width ratio of 5.2 are obtained by LIMJAA with a single-pass laser scanning process in our experiments. LIMJAA is capable of machining various types of difficult-to-process materials with high-quality arrays of micro-channels, square and circle microscale through-holes. The results and disclosed mechanisms in our work provide a deep understanding of the role of laser-induced microjet in improving the processing quality of liquid-assisted laser micromachining.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.