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Multifunctional 3D micro-nanostructures fabricated through temporally shaped femtosecond laser processing for preventing thrombosis and bacterial infection
摘要： Blood-contacting medical devices that directly inhibit thrombosis and bacterial infection without using dangerous anticoagulant and antibacterial drugs can save countless lives but have proved extremely challenging. Here, a useful methodology is proposed that employs temporally shaped femtosecond laser ablation combined with fluorination to fabricate a multifunctional three-dimensional (3D) micro-nanostructures with excellent hemocompatibility, zero cytotoxicity, outstanding biocompatibility, bacterial infection prevention, and long-term effectiveness on NiTi alloys. This multifunctional 3D micro-nanostructures presents 0.1% hemolysis ratio, almost no platelet adhesion and activation, repels blood to inhibit blood coagulation in vitro, maintains 100% cell viability and has exceptional stability over 6 months. Moreover, the multifunctional 3D micro-nanostructures simultaneously suppresses bacterial colonization to form biofilm and kills 100% colonized P. aeruginosa and 95.6% colonized S. aureus after 24h incubation, and bacterial residues can be easily removed. The fabrication method in this work has the advantages of simple processing, high efficiency, high quality and high repeatability, and the new multifunctional 3D micro-nanostructures can effectively prevent thrombosis and bacterial infection, which can be widely applied to various clinical needs such as biomedical devices and implants.
关键词： excellent-hemocompatibility,temporally shaped femtosecond laser,no-contamination,bacterium-free,multifunctional 3D micro-nanostructures
更新于2025-09-19 17:13:59
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Femtosecond Laser-Induced Periodical Nanomodification of Surface Composition
摘要： Nanoscale periodical chemical composition modification of different two-component compound materials GaAs, CdTe, W0.5C and TiC was realized for the first time through multi-shot femtosecond laser irradiation of their surfaces. The resulting surface modification represents periodical nanoscale ripples with different chemical composition in valleys and ridges. The underlying mechanism is related to a sequence of elementary processes, such as laser excitation surface plasmon-polariton, their interference with the incident laser radiation, inhomogeneous surface heating and incongruent cavitation-like material removal. The latter mechanism is responsible for higher evaporation rate of the components with higher volatility, resulting in growth of surface concentration of low-volatility components.
关键词： ablation,surface modification,nanostructures,femtosecond laser pulses
更新于2025-09-19 17:13:59
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Femtosecond laser-assisted cataract surgery (FLACS) in resident training
摘要： This article reviews the history of the femtosecond laser in ophthalmology and its subsequent introduction into the field of cataract surgery. It discusses the innovations that this technology has brought to the field. The article also describes the current system of teaching cataract surgery to ophthalmology residents in the United States and then examines how femtosecond laser-assisted cataract surgery (FLACS) can be a beneficial part of residency education.
关键词： capsulorhexis,cataract surgery,Femtosecond laser,optical coherence tomography
更新于2025-09-19 17:13:59
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Sensitivity amplification of bubble-based all-silica fiber liquid-pressure sensor by using femtosecond laser exposure
摘要： We proposed an efficient and universal sensitivity amplification method for most kinds of sensors based on fiber in-line two-beam Fabry–Perot interferometers (FPIs) by using the femtosecond laser exposure. As an example of two beam FPI, a liquid-pressure sensor based on a micro-bubble at the end of the single mode fiber (SMF) was fabricated. To improve the sensitivity, a third refection mirror in SMF near the bubble at a certain distance was fabricated by using femtosecond laser exposure. As a result, the Vernier effect is generated, which improves the pressure sensitivity from ?0.414 nm/MPa to ?3.973 nm/MPa. Besides, the synchronous measurement of liquid-pressure and temperature can be achieved by monitoring the interference peak and the Vernier envelope at the same time.
关键词： Vernier effect,Femtosecond laser,Liquid-pressure,Sensitivity amplification
更新于2025-09-19 17:13:59
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Spectral absorption control of femtosecond laser-treated metals and application in solar-thermal devices
摘要： Direct femtosecond (fs) laser processing is a maskless fabrication technique that can effectively modify the optical, electrical, mechanical, and tribological properties of materials for a wide range of potential applications. However, the eventual implementation of fs-laser-treated surfaces in actual devices remains challenging because it is difficult to precisely control the surface properties. Previous studies of the morphological control of fs-laser-processed surfaces mostly focused on enhancing the uniformity of periodic microstructures. Here, guided by the plasmon hybridisation model, we control the morphology of surface nanostructures to obtain more control over spectral light absorption. We experimentally demonstrate spectral control of a variety of metals [copper (Cu), aluminium (Al), steel and tungsten (W)], resulting in the creation of broadband light absorbers and selective solar absorbers (SSAs). For the first time, we demonstrate that fs-laser-produced surfaces can be used as high-temperature SSAs. We show that a tungsten selective solar absorber (W-SSA) exhibits excellent performance as a high-temperature solar receiver. When integrated into a solar thermoelectric generation (TEG) device, W-SSA provides a 130% increase in solar TEG efficiency compared to untreated W, which is commonly used as an intrinsic selective light absorber.
关键词： spectral light absorption,plasmon hybridisation model,selective solar absorbers,solar thermoelectric generation,broadband light absorbers,femtosecond laser processing
更新于2025-09-19 17:13:59
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Femtosecond Laser Ablation for Mesoscale Specimen Evaluation
摘要： Focused ion beam machining revolutionized the way samples are studied in materials science. The introduction of this tool enabled researchers to break into new frontiers of research. While this method focused on the nanometer length scale, the mesoscale manufacturing of samples has not seen such advances. It remains a challenge to manufacture sample geometries too large for focused ion beam milling yet too small for conventional machining. Femtosecond laser ablation opens this length scale of sample space and allows the fabrication of numerous useful geometries. This paper outlines a state-of-the-art femtosecond laser machining system that can be used for rapid, micro- and mesoscale sample preparation. To illustrate the utility of this system, stress–strain data are presented for single-crystal Cu micropillars and three microscale tensile test specimens prepared from physical-vapor-deposited Cu and Ni foils.
关键词： Femtosecond laser ablation,mesoscale specimen,microstructure examination,mechanical testing
更新于2025-09-19 17:13:59
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Topical bromfenac sodium in femtosecond laser-assisted cataract surgery
摘要： Purpose: To evaluate the effect of preoperative 0.09% bromfenac ophthalmic solution for the reduction of intraoperative miosis and pain in patients who have undergone femtosecond laser-assisted cataract surgery. Methods: This prospective randomized clinical study included 65 patients with senile cataracts in the absence of signi?cant ocular comorbidity. The patients received 0.09% bromfenac ophthalmic solution or control placebo twice a day for 3 days before surgery. Pupil diameter was measured at the initiation and ?nalization of femtosecond laser-assisted cataract surgery, and pain quanti?cation was assessed by an analogous pain scale after one day of follow-up. Results: A total of 65 patients were randomly divided into two groups. Five patients were excluded due to defective coupling with the laser interface. Each of the 60 patients was randomized to receive preoperative topical treatment with either 0.09% bromfenac or 0.1% sodium hyaluronate. Baseline characteristics were similar between groups for age and gender. The mean change in horizontal and vertical pupil diameter from the preoperative to post-femtosecond laser measurements were signi?cantly less in the bromfenac group than in the placebo group (0.43 ± 0.6 vs. 1.71 ± 0.9, P < 0.001 and 0.40 ± 0.6 vs. 1.78 ± 0.9, P < 0.001, respectively). Compared with untreated patients, the quanti?cation of pain one day after the procedure was signi?cantly lower in the 0.09% bromfenac group (46.7% with a score of 3 vs. 50% with a score of 1, P < 0.001, respectively). Conclusions: The maintenance of pupil dilation and the prevention of miosis were more effective in the 0.09% bromfenac group than in the control group. Likewise, the greater control of postoperative pain represented an additional signi?cant bene?t.
关键词： Pupil,Cataract,NSAID,Bromfenac,Femtosecond laser
更新于2025-09-19 17:13:59
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Designing a??Supermetalphobica?? Surfaces that Greatly Repel Liquid Metal by Femtosecond Laser Processing: Does the Surface Chemistry or Microstructure Play a Crucial Role?
摘要： It is demonstrated that the wettability of liquid metal (LM) on a substrate is very different from the water wettability. Superhydrophobic and superhydrophilic silicon and polydimethylsiloxane surfaces, respectively, are obtained by femtosecond laser processing and proper chemical modification. All of the structured surfaces have excellent LM repellence, that is, supermetalphobicity, in spite of superhydrophobicity or superhydrophilicity. The experimental comparison and contact model analysis reveal that surface microstructure actually plays a crucial role in endowing a surface with supermetalphobicity while surface chemistry has a little influence on the formation of supermetalphobicity, because the liquid/solid contact is replaced by a solid/solid contact mode for a LM droplet on a textured substrate. It is believed that the established principle for creating supermetalphobic surfaces will enable to accelerate the application progress of LM materials in flexible circuits and liquid robots.
关键词： superhydrophobicity,eutectic gallium–indium,liquid–metal repellence,femtosecond laser processing,supermetalphobicity
更新于2025-09-19 17:13:59
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High-Performance Free-Standing Flexible Photodetectors Based on Sulfur-Hyperdoped Ultrathin Silicon
摘要： Flexible photodetectors (PDs) prepared with silicon-based materials have received considerable attention for use in a wide range of portable and wearable applications. In this study, we present the first free-standing flexible PD based on sulfur-hyperdoped ultrathin silicon, which was fabricated using a femtosecond laser in SF6 atmosphere. It is found that the fabricated device exhibits excellent performance of broadband photoresponse from 400 to 1200 nm, with peak responsivity of 63.79 A/W @ 870 nm at a low bias voltage of -2 V, corresponding to an external quantum efficiency reaching 9092%, which surpasses most values reported for silicon-based flexible PDs. In addition, the device shows a fast response speed (rise time τr=68 μs) and stable detection performance with good mechanical flexibility. The high-performance PD described here suggests a promising way in flexible applications for sensors, imaging systems, and optical communication systems.
关键词： flexible photodetector,ultrathin silicon,black silicon,sulfur-hyperdoped,femtosecond laser
更新于2025-09-19 17:13:59
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Submicron bubbles/voids formation in the subsurface region of soda-lime glass by single pulse fs laser-induced spallation
摘要： The formation of bubbles near the surface of soda-lime glass induced by single pulse irradiation with Ti: Sapphire laser of a wavelength of 775 nm and 150 fs pulse duration below the laser ablation threshold is reported. The bubbles with a diameter of 0.3 to 3 μm are much smaller than the spot size of ~12 μm and exhibit a semi-spherical surface, an ellipsoidal void and an upper shell thickness of approx. 100 nm. The bubbles are formed in a narrow energy range between bulk glass modification and glass ablation. The bubbles formation is accomplished with some changes of the glass morphology around the bubbles. Damaged bubbles occur near the upper laser energy limit for bubbles formation that show nanoholes or slits in the bubbles shell and opened shells exposing the bottom of the void. It is suggested, that the bubble forming mechanism is related to nonlinear processes of laser photon absorption, laser-induced spallation processes, materials heating after electron relaxation, and thermal driven, viscoplastic-mechanical processes. Mainly the material composition gradient of the soda-lime glass near the surface that affects photon absorption, melting, ablation and material expansion processes enable the formation of these bubbles. The void inside the bubble is formed first by pre-spallation resulting in a detached layer that is lifted further forming the bubbles shell by subsurface laser ablation/evaporation processes of the bulk glass. The upper shell of the bubble is formed by a thermally stable crust of corroded soda-lime glass. The results may have valuable impact to laser ablation processes for high precision fabrication. Further, the fast fabrication of such 3D submicron structures due to the single pulse interaction with the glass enables new technical processes for potential applications in sensing, photonic or microfluidic.
关键词： soda-lime glass,surface modification,single pulse,nonlinear absorption,femtosecond laser,bubble,spallation
更新于2025-09-19 17:13:59