NANOTECHNOLOGY
·
2024
·Vol. 35
·期 36
·365301
·
IF 2.9
Lisha Fan,Xianwei Tang,Shuowen Zhang,Ling Wu,Tianzhen Zhao,Xiaoyu Ding,Huaping Wu,Jianhua Yao
Multi-photon reduction (MPR) based on femtosecond laser makes rapid prototyping and molding in micro-nano scale feasible, but is limited in material selectivity due to lack of the understanding of the reaction mechanism in MPR process. In this paper, additively manufacturing of complex silver-based patterns through MPR is demonstrated. The effects of laser parameters, including laser pulse energies and scanning speeds, on the structural and chemical characteristics of the printed structures are systematically investigated. The results show that the geometric size of printed cubes deviates from the designed size further by increasing laser pulse energy or decreasing scanning speed. The reaction mechanism of MPR is revealed by studying the elemental composition and chemical structures of printed cubes. The evolution of Raman spectra upon the laser processing parameters suggests that the MPR process mainly includes two processes: reduction and decomposition. In the MPR process, silver ions are reduced and grow into particles by accepting the electrons from ethonal molecules; meanwhile carboxyl groups in polyvinylpyrrolidone are decomposed and form amorphous carbon that is attached on the surface of silver particles. The conductivity of silver wires fabricated by MPR reaches 2 × 105 S m−1 and stays relatively constant as varying their cross section area, suggesting excellent electrical conduction. The understanding of the MPR process would accelerate the development of MPR technology and the implementation of MPR in micro-electromechanical systems could therefore be envisioned.
研究领域:
材料科学
·
微纳米制造
·
光学工程
✓ 已验证
DOI
高影响因子
Advanced Materials Technologies
·
2024
·
IF 6.4
Mingliang Li,Ping Wang,Hui Zhang,Ping Liu,Guangli Liu,Cong Sui,Runhuai Yang,Tingting Luo
Microbots have shown considerable potential in the biomedical field. Their capability to target specific areas for diagnosis, treatment, and other applications with minimal invasiveness is particularly advantageous. However, complex application environments and harsh driving conditions greatly limit the locomotion behaviors of microbots, and therefore the locomotion mode of microbots deserves more exploration and research. This study focuses on a near-infrared light-driven bubble-propelled microbot. The photothermally responsive materials used in the design are modified to enhance bubble generation properties. Additionally, the controlled 3D printing preparation process can indirectly influence the bubble aggregation pathway by altering the microbot's micro-nanostructured porous structure. Ultimately, by adjusting the laser parameters, the microbot can be controlled to achieve a variety of locomotion modes. Furthermore, the experimental observations and theoretical analysis of the microbot's locomotion modes are summarized. A preliminary digital description is provided, which verifies the feasibility of controlling these locomotion modes. This lays the foundation for the precise control of microbots in future applications.
研究领域:
生物医学工程
·
材料科学
·
机器人学
✓ 已验证
产品关联
DOI
高影响因子
Frontiers of Optoelectronics
·
2024
·Vol. 17
·期 1
·1-11
·
IF 4.1
Li Qi,Bai Ruijie,Guo Lianbo,Gao Yang
A highly sensitive temperature sensing array is prepared by all laser direct writing (LDW) method, using laser induced silver (LIS) as electrodes and laser induced graphene (LIG) as temperature sensing layer. A finite element analysis (FEA) photothermal model incorporating a phase transition mechanism is developed to investigate the relationship between laser parameters and LIG properties, providing guidance for laser processing parameters selection with laser power of 1–5 W and laser scanning speed (greater than 50 mm/s). The deviation of simulation and experimental data for widths and thickness of LIG are less than 5% and 9%, respectively. The electrical properties and temperature responsiveness of LIG are also studied. By changing the laser process parameters, the thickness of the LIG ablation grooves can be in the range of 30–120 μm and the resistivity of LIG can be regulated within the range of 0.031–67.2 Ω·m. The percentage temperature coefficient of resistance (TCR) is calculated as − 0.58%/°C. Furthermore, the FEA photothermal model is studied through experiments and simulations data regarding LIS, and the average deviation between experiment and simulation is less than 5%. The LIS sensing samples have a thickness of about 14 μm, an electrical resistivity of 0.0001–100 Ω·m is insensitive to temperature and pressure stimuli. Moreover, for a LIS-LIG based temperature sensing array, a correction factor is introduced to compensate for the LIG temperature sensing being disturbed by pressure stimuli, the temperature measurement difference is decreased from 11.2 to 2.6 °C, indicating good accuracy for temperature measurement. Graphical
研究领域:
材料科学
·
纳米技术
·
传感器
·
光电子学
·
热分析
·
微纳加工
✓ 已验证
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2023
·
IF 5.4
Jiabei Zhang,Yucheng Wu,Zhaoyang Zhang,Shicheng Sun,Shaojing Gu,Shuai Yang,Hao Zhu
Excessive P content (≥ 10 wt%) easily leads to cracks on the surface of electrodeposited Ni P coatings, causing rapid deterioration of corrosion performance. This study uses picosecond laser remelting (LR) technology to close cracks and improve corrosion performance. The influence of the laser parameters on the quality of laser-remelted (LRed) coatings in ambient air is discussed in detail, and the corrosion performance is evaluated through electrochemical corrosion tests. The results indicated that the scanning rate, laser power, and repetition frequency significantly affect the degree of crack closure and LRed defects. For cracks of similar sizes, both multiple-LR with a lower power (10.4 W, five times) and single-LR with a higher power (19.2 W, once) achieved an excellent crack closure. After single-LR, the surface roughness increased from 3.9 ± 0.3 nm to 33.4 ± 3.2 nm. In addition, the LRed layer crystallized from the initial amorphous state. Although the energy-dispersive spectroscopy results indicated that the oxidation behavior during the LR process was insignificant, X-ray photoelectron spectroscopy showed that the surface composition evolved from Ni/Ni–P compounds to Ni–POx after LR. Electrochemical corrosion tests indicated that the corrosion current density decreased approximately three times from 9.19 × 10 −6 to 2.91 × 10 −6 A/cm 2 after LR. Moreover, the corrosion mechanism shifted from the original stress corrosion to pitting corrosion . Thus, the LR technology can effectively improve the corrosion performance and reduce the issues caused by cracks.
研究领域:
材料科学
·
电化学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）