Submit to Micromachines Review for Micromachines Propose a Special Issue

Journal Menu

Journal Browser

Advanced Materials, Structures and Processing Technologies Based on Pulsed Laser

Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Micromachines (ISSN 2072-666X). This special issue belongs to the section "E：Engineering and Technology".

Deadline for manuscript submissions: closed (31 October 2021) | Viewed by 16322

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special issue Advanced Materials, Structures and Processing Technologies Based on Pulsed Laser book cover image

Share This Special Issue

Special Issue Editors

Dr. Youmin Rong

E-Mail Website
Guest Editor

School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Interests: ultra-fast laser processing; high-power laser processing; laser processing process inspection
Special Issues, Collections and Topics in MDPI journals

Dr. Congyi Wu

E-Mail Website
Guest Editor

School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Interests: laser manufacturing; ultrafast laser processing; flexible electronics; polymer laser processing; flexible sensor; wearable devices; human–machine interface
Special Issues, Collections and Topics in MDPI journals

Prof. Dr. Yu Huang

E-Mail Website
Guest Editor

School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
Interests: laser manufacturing; ultrafast laser processing; laser welding; high power laser manufacturing; laser processing equipment

Special Issue Information

Dear Colleagues,

Pulsed lasers are lasers with a single laser pulse width of less than 0.25 s, operating only once every certain time interval. Commonly used pulsed lasers are nanosecond, femtosecond, and picosecond lasers. A pulsed laser produces short pulses with short a interaction time with the material, which can largely avoid impacts on the thermal movement of molecules and has minimal thermal impact on surrounding materials, thus having significant advantages in precision microfabrication. It is now widely used in flexible electronics, chips, medicine, and other fields, such as photographic resin curing, micro-welding, vision correction, heart stent manufacturing, etc. However, as an emerging processing technology, the application prospects of pulsed lasers have yet to be fully expanded, and there is still a need to continuously explore mechanisms of interaction with materials, manufacture advanced functional structures, and develop advanced process technologies.

This Special Issue of Micromachines, “Advanced Materials, Structures and Processing Technologies Based on Pulsed Lasers”, seeks to showcase research papers, communications, and review articles that focus on new materials, structures, and processing technologies based on pulsed lasers, exploring the application of pulsed lasers in various fields. We hope that the papers will encompass the next key technological leaps that will further extend the applications of pulsed lasers. Suitable contributions can be related to (but are not restricted to) new material pulsed laser interaction technologies, new structure pulsed laser processing technologies, new pulsed laser processing technology, and the expansion of pulsed laser applications in flexible electronics, batteries, aerospace, navigation, etc.

Dr. Youmin Rong
Dr. Congyi Wu
Prof. Dr. Yu Huang
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Micromachines is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Dr. Youmin Rong
Dr. Congyi Wu
Prof. Dr. Yu Huang
Guest Editors

Manuscript Submission Information

Keywords

pulsed laser
nanosecond laser
femtosecond laser
picosecond laser
interaction mechanism
functional structure
process technology

Published Papers (7 papers)

Download All Papers

Editorial

Jump to: Research

3 pages, 169 KiB

Open AccessEditorial

Editorial for the Special Issue on Advanced Materials, Structures and Processing Technologies Based on Pulsed Laser

by Youmin Rong, Congyi Wu and Yu Huang

Micromachines 2021, 12(12), 1507; https://0-doi-org.brum.beds.ac.uk/10.3390/mi12121507 - 01 Dec 2021

Viewed by 1541

Abstract

Pulsed lasers are lasers with a single laser pulse width of less than 0 [...] Full article

(This article belongs to the Special Issue Advanced Materials, Structures and Processing Technologies Based on Pulsed Laser)

Research

Jump to: Editorial

14 pages, 13142 KiB

Open AccessArticle

Temperature Field-Assisted Ultraviolet Nanosecond Pulse Laser Processing of Polyethylene Terephthalate (PET) Film

by Jun Xu, Youmin Rong, Weinan Liu, Tian Zhang, Guoqiang Xin, Yu Huang and Congyi Wu

Micromachines 2021, 12(11), 1356; https://0-doi-org.brum.beds.ac.uk/10.3390/mi12111356 - 02 Nov 2021

Cited by 3 | Viewed by 1753

Abstract

Understanding the mechanism of and how to improve the laser processing of polymer films have been important issues since the advent of the procedure. Due to the important role of a photothermal mechanism in the laser ablation of polymer films, especially in transparent polymer films, it is both important and effective to adjust the evolution of heat and temperature in time and space during laser processing by simply adjusting the ambient environment so as to improve and understand the mechanism of this procedure. In this work, studies on the pyrolysis of PET film and on temperature field-assisted ultraviolet nanosecond (UV-ns) pulse laser processing of polyethylene terephthalate (PET) film were performed to investigate the photothermal ablation mechanism and the effects of temperature on laser processing. The results showed that the UV-ns laser processing of PET film was dominated by the photothermal process, in which PET polymer chains decomposed, melted, recomposed and reacted with the ambient gases. The ambient temperature changed the heat transfer and temperature distribution in the laser processing. Low ambient temperature reduced the thermal effect and an increase in ambient temperature improved its efficiency (kerf width: 39.63 μm at −25 °C; 48.30 μm at 0 °C; 45.81 μm at 25 °C; 100.70 μm at 100 °C) but exacerbated the thermal effect. Full article

(This article belongs to the Special Issue Advanced Materials, Structures and Processing Technologies Based on Pulsed Laser)

► Show Figures

Figure 1

18 pages, 4779 KiB

Open AccessArticle

Modulation and Control of Wettability and Hardness of Zr-Based Metallic Glass via Facile Laser Surface Texturing

by Qinghua Wang, Yangyang Cheng, Zhixian Zhu, Nan Xiang and Huixin Wang

Micromachines 2021, 12(11), 1322; https://0-doi-org.brum.beds.ac.uk/10.3390/mi12111322 - 28 Oct 2021

Cited by 18 | Viewed by 1902

Abstract

Bulk metallic glass (BMG) has received consistent attention from the research community owing to its superior physical and mechanical properties. Modulating and controlling the surface functionalities of BMG can be more interesting for the surface engineering community and will render more practical applications. In this work, a facile laser-based surface texturing technique is presented to modulate and control the surface functionalities (i.e., wettability and hardness) of Zr-based BMG. Laser surface texturing was first utilized to create periodic surface structures, and heat treatment was subsequently employed to control the surface chemistry. The experimental results indicate that the laser textured BMG surface became superhydrophilic immediately upon laser texturing, and it turned superhydrophobic after heat treatment. Through surface morphology and chemistry analyses, it was confirmed that the wettability transition could be ascribed to the combined effects of laser-induced periodic surface structure and controllable surface chemistry. In the meantime, the microhardness of the BMG surface has been remarkably increased as a result of laser surface texturing. The facile laser-based technique developed in this work has shown its effectiveness in modification and control of the surface functionalities for BMG, and it is expected to endow more useful applications. Full article

(This article belongs to the Special Issue Advanced Materials, Structures and Processing Technologies Based on Pulsed Laser)

► Show Figures

Graphical abstract

15 pages, 4776 KiB

Open AccessArticle

PI Film Laser Micro-Cutting for Quantitative Manufacturing of Contact Spacer in Flexible Tactile Sensor

by Congyi Wu, Tian Zhang, Yu Huang and Youmin Rong

Micromachines 2021, 12(8), 908; https://0-doi-org.brum.beds.ac.uk/10.3390/mi12080908 - 30 Jul 2021

Cited by 8 | Viewed by 2124

Abstract

The contact spacer is the core component of flexible tactile sensors, and the performance of this sensor can be adjusted by adjusting contact spacer micro-hole size. At present, the contact spacer was mainly prepared by non-quantifiable processing technology (electrospinning, etc.), which directly leads to unstable performance of tactile sensors. In this paper, ultrathin polyimide (PI) contact spacer was fabricated using nanosecond ultraviolet (UV) laser. The quality evaluation system of laser micro-cutting was established based on roundness, diameter and heat affected zone (HAZ) of the micro-hole. Taking a three factors, five levels orthogonal experiment, the optimum laser cutting process was obtained (pulse repetition frequency 190 kHz, cutting speed 40 mm/s, and RNC 3). With the optimal process parameters, the minimum diameter was 24.3 ± 2.3 μm, and the minimum HAZ was 1.8 ± 1.1 μm. By analyzing the interaction process between nanosecond UV laser and PI film, the heating-carbonization mechanism was determined, and the influence of process parameters on the quality of micro-hole was discussed in detail in combination with this mechanism. It provides a new approach for the quantitative industrial fabrication of contact spacers in tactile sensors. Full article

(This article belongs to the Special Issue Advanced Materials, Structures and Processing Technologies Based on Pulsed Laser)

► Show Figures

Figure 1

15 pages, 6705 KiB

Open AccessArticle

Medical Applications of Diode Lasers: Pulsed versus Continuous Wave (cw) Regime

by Michał Michalik, Jacek Szymańczyk, Michał Stajnke, Tomasz Ochrymiuk and Adam Cenian

Micromachines 2021, 12(6), 710; https://0-doi-org.brum.beds.ac.uk/10.3390/mi12060710 - 17 Jun 2021

Cited by 13 | Viewed by 3587

Abstract

The paper deals with the medical application of diode-lasers. A short review of medical therapies is presented, taking into account the wavelength applied, continuous wave (cw) or pulsed regimes, and their therapeutic effects. Special attention was paid to the laryngological application of a pulsed diode laser with wavelength 810 nm, and dermatologic applications of a 975 nm laser working at cw and pulsed mode. The efficacy of the laser procedures and a comparison of the pulsed and cw regimes is presented and discussed. Full article

(This article belongs to the Special Issue Advanced Materials, Structures and Processing Technologies Based on Pulsed Laser)

► Show Figures

Figure 1

11 pages, 23482 KiB

Open AccessArticle

Microstructure Study of Pulsed Laser Beam Welded Oxide Dispersion-Strengthened (ODS) Eurofer Steel

by Jia Fu, Ian Richardson and Marcel Hermans

Micromachines 2021, 12(6), 629; https://0-doi-org.brum.beds.ac.uk/10.3390/mi12060629 - 28 May 2021

Cited by 4 | Viewed by 2183

Abstract

Oxide dispersion-strengthened (ODS) Eurofer steel was laser welded using a short pulse duration and a designed pattern to minimise local heat accumulation. With a laser power of 2500 W and a duration of more than 3 ms, a full penetration can be obtained in a 1 mm thick plate. Material loss was observed in the fusion zone due to metal vaporisation, which can be fully compensated by the use of filler material. The solidified fusion zone consists of an elongated dual phase microstructure with a bimodal grain size distribution. Nano-oxide particles were found to be dispersed in the steel. Electron backscattered diffraction (EBSD) analysis shows that the microstructure of the heat-treated joint is recovered with substantially unaltered grain size and lower misorientations in different regions. The experimental results indicate that joints with fine grains and dispersed nano-oxide particles can be achieved via pulsed laser beam welding using filler material and post heat treatment. Full article

(This article belongs to the Special Issue Advanced Materials, Structures and Processing Technologies Based on Pulsed Laser)

► Show Figures

Figure 1

9 pages, 3275 KiB

Open AccessArticle

A Comparative Study on the Wettability of Unstructured and Structured LiFePO₄ with Nanosecond Pulsed Fiber Laser

by Mulugeta Gebrekiros Berhe and Dongkyoung Lee

Micromachines 2021, 12(5), 582; https://0-doi-org.brum.beds.ac.uk/10.3390/mi12050582 - 20 May 2021

Cited by 12 | Viewed by 2281

Abstract

The wettability of electrodes increases the power and energy densities of the cells of lithium-ion batteries, which is vital to improving their electrochemical performance. Numerous studies in the past have attempted to explain the effect of electrolyte and calendering on wettability. In this work, the wettability behavior of structured and unstructured LiFePO₄ electrodes was studied. Firstly, the wettability morphology of the structured electrode was analyzed, and the electrode geometry was quantified in terms of ablation top and bottom width, ablation depth, and aspect ratio. From the result of the geometry analysis, the minimum measured values of aspect ratio and ablation depth were used as structured electrodes. Laser structuring with pitch distances of 112 μm, 224 μm, and 448 μm was applied. Secondly, the wettability of the electrodes was measured mainly by total wetting time and electrolyte spreading area. This study demonstrates that the laser-based structuring of the electrode increases the electrochemically active surface area of the electrode. The electrode structured with 112 μm pitch distance exhibited the fastest wetting at a time of 13.5 s. However, the unstructured electrode exhibited full wetting at a time of 84 s. Full article

(This article belongs to the Special Issue Advanced Materials, Structures and Processing Technologies Based on Pulsed Laser)

► Show Figures