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In this paper, a new scheme for generating a wide gamut of structural colors on the thin‐film‐stack‐based (TFSB) substrates is proposed. The TFSB surfaces consist of titanium/random gold nanoparticles (AuNPs) and titanium/ random gold and copper nanoparticles (Au+CuNPs), which can trigger more resonance absorption and widen the color gamut. The electric fields in two designed structures are simulated, and the results showed that the random distribution of AuNPs and Au+CuNPs enhance the uniform local surface plasmon resonance (LSPR) response. This enhancement is crucial in broadening the coverage of the reflection spectrum, which enables the generation of a wide range of colors, including green and red. The influence of laser parameters on the color of TFSB substrates and tested their durability in terms of time is analyzed. Finally, a color palette and made structural color patterns on TFSB by nanosecond pulsed laser are prepared. The proposed new scheme can be easily fabricated by magnetron sputtering without requiring additional procedures, which can open new perspectives in plasmonic colors. This work demonstrates that the promising potential of methods in creating a wide color gamut on metallic surfaces. Additionally, it serves as a means to store information for the preservation and protection of traditional cultures. [ABSTRACT FROM AUTHOR]

The use of ytterbium laser to obtain colored titanium surfaces is a suitable strategy to improve the aesthetic soft tissue results and reduce implant failures in oral rehabilitation. To investigate the relationship between novel laser-colored surfaces and peri-implant soft tissues, Human Gingival Fibroblasts (HGFs) were cultured onto 12 colored titanium grade 1 light fuchsia, dark fuchsia, light gold, and dark gold disks and their viability (MTT Assay), cytotoxicity (lactate dehydrogenase release), and collagen I secretion were compared to the machined surface used as control. Optical and electronic microscopies showed a HGF growth directly correlated to the roughness and wettability of the colored surfaces. A higher viability percentage on dark fuchsia (125%) light gold (122%), and dark gold (119%) samples with respect to the machined surface (100%) was recorded. All specimens showed a statistically significant reduction of LDH release compared to the machined surface. Additionally, a higher collagen type I secretion, responsible for an improved adhesion process, in light fuchsia (3.95 μg/mL) and dark gold (3.61 μg/mL) compared to the machined surface (3.59 μg) was recorded. The in vitro results confirmed the innovative physical titanium improvements due to laser treatment and represent interesting perspectives of innovation in order to ameliorate aesthetic dental implant performance and to obtain more predictable osteo and perio-osteointegration long term implant prognosis. [ABSTRACT FROM AUTHOR]

Laser-induced coloration (LIC) on metallic surfaces has attracted interest for various applications. Achieving precise color generation still presents significant challenges, caused by the complex correlation between laser processing parameters and induced colors. Limited to parameter sensitivity, complex coupling of several processing parameters and unevenness of the coloring, it is difficult to achieve accurate parameter prediction and color control with traditional experimental or neural network based methods. Problems such as poor color acquisition and insufficient consideration of processing parameters exist in current studies. In this regard, a high-quality and full-pixel LIC color dataset processed by the Octree algorithm is established. In addition, modified ANN models and regulation cocktails are adopted to predict processing parameters (waveform, frequency, power, scanning spacing, scanning speed), and HSV (color model describes colors in Hue, Saturation and Value channels) values, respectively. The models proposed in this paper achieve accurate parameter control and color prediction. For Model MOC, its training and test RMSE reaches 7.82 and 8.33. Besides, precise RGB artworks were processed applying the predicted parameters. For Model MLP + C, RMSE reaches 4.83 for test set. The difference in color between the predicted color and the actual color reaches Δ E ⁎ ≤ 5. With well-tuned ANN models and curated LIC dataset, the correlation between processing parameters and induced colors can be revealed. Thus, the processing parameters for LIC are optimized. • Uneven color in LIC is studied by full factorial experiment and microstructural analysis. • The Octree Algorithm enhances the quality of LIC dataset. • Five main laser parameters are considered in the experiment, suitable for application. • The adoption of regulation cocktails balances the efficacy and accuracy of the model. [ABSTRACT FROM AUTHOR]