- 标题
- 摘要
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- 实验方案
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Low-Power, Multimodal Laser Micromachining of Materials for Applications in sub-5 ?μm Shadow Masks and sub-10 ?μm Interdigitated Electrodes (IDEs) Fabrication
摘要： Laser micromachining is a direct write microfabrication technology that has several advantages over traditional micro/nanofabrication techniques. In this paper, we present a comprehensive characterization of a QuikLaze 50ST2 multimodal laser micromachining tool by determining the ablation characteristics of six (6) different materials and demonstrating two applications. Both the thermodynamic theoretical and experimental ablation characteristics of stainless steel (SS) and aluminum are examined at 1064 nm, silicon and polydimethylsiloxane (PDMS) at 532 nm, and Kapton? and polyethylene terephthalate at 355 nm. We found that the experimental data aligned well with the theoretical analysis. Additionally, two applications of this multimodal laser micromachining technology are demonstrated: shadow masking down to approximately 1.5 μm feature sizes and interdigitated electrode (IDE) fabrication down to 7 μm electrode gap width.
关键词： interdigitated electrodes,ablation characteristics,multimodal laser micromachining,shadow mask
更新于2025-09-19 17:13:59
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[IEEE 2020 8th International Winter Conference on Brain-Computer Interface (BCI) - Gangwon, Korea (South) (2020.2.26-2020.2.28)] 2020 8th International Winter Conference on Brain-Computer Interface (BCI) - Implementation of multi-connected single-channel functional near-infrared spectroscopy system for hyperscanning study
摘要： A drug delivery system is used for targeting drugs to specific cells. Various drug carriers, that also reduce the side effects of unbound drugs, have been introduced and commercialized in the pharmaceutical field. Among them, synthetic biodegradable polymers have received much attention attributed to their low toxicity, controllable biodegradation rates, manufacturability, and low costs. This paper reviews the salient characteristics of biodegradable polymers as drug carriers and their microfabrication methods. The reviewed microfabrication methods include laser micromachining, rapid prototyping, replication, emulsification, microfluidic fabrication, and X-ray-lithography-based methods. For these microfabrication methods, critical dimensions, feature variety, solvent compatibility, production throughput, and tooling requirements are also summarized.
关键词： poly-capro-lactone (PCL),laser micromachining,emulsification,microfluidics,poly(lactic-co-glycolic acid) (PLGA),biodegradable polymers,Drug delivery systems (DDS),rapid prototyping,replication,x-ray-lithography,microfabrication,drug carriers
更新于2025-09-19 17:13:59
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Femtosecond lasers for high-precision orthopedic surgery
摘要： Laser micromachining with ultrashort pulses has shown great promise for clean, safe surgical treatment of bone tissue. However, comparisons of performance and development of “best practice” have been hampered by the difficulty of comparing results across a wide variety of experimental approaches and under surgically irrelevant conditions (e.g., dried, dead bone). Using a femtosecond (fs) pulsed laser system (τ = 140 fs, repetition rate = 1 kHz, λ = 800 nm), a comprehensive study of femtosecond laser microsurgery using the standard metrics of laser micromachining (ablation threshold, incubation effects, ablation rates, effect of focal point depth within the material and heat affected zone (HAZ)) was conducted on live, freshly harvested bovine and ovine cortical bone. Three important points of optimism for future implementation in the surgical theatre were identified: (1) the removal of material is relatively insensitive to the focal point depth within the material, removing the need for extreme depth precision for excellent performance; (2) femtosecond laser ablation of fresh bone demonstrates very little incubation effect, such that multiple passes of the laser over the same region of bone removes the same amount of material; and (3) the complete absence of collateral damage, heat- or shock-induced, on both the macro- and microscopic scales can be achieved readily, within a broad parameter range. Taken together, these results indicate a handheld or robotic deployed fiber laser platform for femtosecond laser microsurgery is a very viable prospect.
关键词： Laser ablation,Ultrafast laser micromachining,Femtosecond microsurgery,Laser micromachining,Orthopedic surgery
更新于2025-09-16 10:30:52
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Controlled Fabrication of Micro/Nano-Structures on Germanium Using Ultrashort Laser Pulses under Ambient Conditions
摘要： A technique for ordered fabrication of periodic freestanding micro/nano-structures on the crystalline germanium (Ge) <100> surfaces with 1064 nm wavelength ultrashort laser pulses under ambient conditions is presented. The laser radiation fluence used for obtaining the structures is close to the melting threshold (0.1 J/cm2) of Ge. The dimensions of structures range from hundreds of nanometres to a few microns. The orientation of the periodic surface structures depends on laser beam polarization direction. Arrays of structures are formed in rows parallel to the sample movement direction for samples machined with s-polarized laser pulses, but formed in the direction perpendicular to the movement for p-polarized pulses. The structures are fabricated under variable temperatures on sample surface owing to the changed interference between incident and reflected laser beams. A micro-Raman analysis of the processed surfaces shows a minor change in the spectral intensity as compared to the unprocessed surface and the material retains its crystallinity after laser irradiation.
关键词： Nano-structures,Femtosecond laser,Micromachining,Germanium
更新于2025-09-16 10:30:52
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Conical microstructuring of titanium by reactive gas assisted laser texturing
摘要： Femtosecond laser micromachining is an important and flexible method to generate precisely targeted surfaces on various materials. On titanium, the laser structuring process strongly depends on the laser parameters. For example, an increasement of the pulse length and repetition rate favors melting processes instead of ablation and microstructuring. We report on an investigation of reactive halogens (iodine, bromine, chlorine) and halocarbons as additives to the laser structuring process of pure titanium and the common alloy Ti-6Al-4V with 0.75 ps laser pulses. The choice of the halogen allows control of whether solely the chemical composition or the surface microstructure should be altered. Bromine was found to be an efficient additive to generate homogeneous microstructures based on micropillars at convenient conditions (air, atmospheric pressure). The resulting surfaces have been characterised by thermal emission infrared photography, scanning electron microscopy, energy dispersive X-ray spectroscopy, reflective UV/Vis spectroscopy and contact angle measurements. The bromine/air processed titanium surfaces revealed superhydrophilicity, strongly increased thermal emissivity and a high absorptivity (“black metal”).
关键词： Superhydrophilicity,Reactive halogens,Absorptivity,Titanium,Femtosecond laser micromachining,Microstructuring,Thermal emissivity
更新于2025-09-16 10:30:52
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Fabrication of Silicon Microfluidic Chips for Acoustic Particle Focusing Using Direct Laser Writing
摘要： We have developed a fast and simple method for fabricating microfluidic channels in silicon using direct laser writing. The laser microfabrication process was optimised to generate microfluidic channels with vertical walls suitable for acoustic particle focusing by bulk acoustic waves. The width of the acoustic resonance channel was designed to be 380 μm, branching into a trifurcation with 127 μm wide side outlet channels. The optimised settings used to make the microfluidic channels were 50% laser radiation power, 10 kHz pulse frequency and 35 passes. With these settings, six chips could be ablated in 5 h. The microfluidic channels were sealed with a glass wafer using adhesive bonding, diced into individual chips, and a piezoelectric transducer was glued to each chip. With acoustic actuation at 2.03 MHz a half wavelength resonance mode was generated in the microfluidic channel, and polystyrene microparticles (10 μm diameter) were focused along the centre‐line of the channel. The presented fabrication process is especially interesting for research purposes as it opens up for rapid prototyping of silicon‐glass microfluidic chips for acoustofluidic applications.
关键词： acoustophoresis,acoustofluidics,ultrasound,laser micromachining,particle manipulation,microfabrication
更新于2025-09-16 10:30:52
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Maskless, rapid manufacturing of glass microfluidic devices using a picosecond pulsed laser
摘要： Conventional manufacturing of glass microfluidic devices is a complex, multi-step process that involves a combination of different fabrication techniques, typically photolithography, chemical/dry etching and thermal/anodic bonding. As a result, the process is time-consuming and expensive, in particular when developing microfluidic prototypes or even manufacturing them in low quantity. This report describes a fabrication technique in which a picosecond pulsed laser system is the only tool required to manufacture a microfluidic device from transparent glass substrates. The laser system is used for the generation of microfluidic patterns directly on glass, the drilling of inlet/outlet ports in glass covers, and the bonding of two glass plates together in order to enclose the laser-generated patterns from the top. This method enables the manufacturing of a fully-functional microfluidic device in a few hours, without using any projection masks, dangerous chemicals, and additional expensive tools, e.g., a mask writer or bonding machine. The method allows the fabrication of various types of microfluidic devices, e.g., Hele-Shaw cells and microfluidics comprising complex patterns resembling up-scaled cross-sections of realistic rock samples, suitable for the investigation of CO2 storage, water remediation and hydrocarbon recovery processes. The method also provides a route for embedding small 3D objects inside these devices.
关键词： glass microfluidic devices,laser micromachining,picosecond pulsed laser,maskless manufacturing,laser microwelding,rapid prototyping
更新于2025-09-12 10:27:22
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Faster Femtosecond Laser Processing using a Dual-Focus SLM Emulated Lens
摘要： The generation of multiple beams is an established method to increase the processing speed of advanced laser-based material processing techniques. This multi-foci approach has shown promising results in laser micromachining, scanning microscopy, optical data storage, or optical tweezer arrays. Of particular interest is its application to manufacturing bigger objects where laser treatment is required over surfaces on the centimetre scale or larger. Using a Spatial Light Modulator (SLM), such parallelisation has been studied over the last few years by splitting the input beam into multiple beams (up to 1000 beams [1]) for simultaneous machining on a plane perpendicular to the propagation axis. This method is primarily based on holographic femtosecond laser processing [2] where computer-generated holograms (CGH) are displayed on an SLM. Further applications include phase distortion and lens aberration correction [3], or for four-dimension light shaping [4]. The SLM provides unique features for dynamic pulse shaping, more efficient use of the laser energy, or the machining of complex shapes.
关键词： spatial light modulator,laser micromachining,computer-generated holograms,dual-focus SLM,femtosecond laser processing
更新于2025-09-12 10:27:22
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High-Speed All-Optical Modulator Based on a Polymer Nanofiber Bragg Grating Printed by Femtosecond Laser
摘要： On-chip optical modulator for high-speed information processing system has been widely investigated by majority of researchers but the connection with the fiber system is a difficulty. The fiber-based optical modulator is a good solution to this problem. Fiber Bragg Grating has good potential to be used as an optical modulator because of its linear temperature response, narrow bandwidth, and compact structure. In this paper, a new fiber-integrated all-optical modulator has been realized based on a polymer nanofiber Bragg grating printed by femtosecond laser. This device exhibits a fast temporal response of 176 ns and a good linear modulation of -45.43 pm/mW. Moreover, its stability has also been studied. This work firstly employs Bragg resonance to realize a fiber-integrated all-optical modulator and paves the way toward realization of multifunctional lab-in-fiber devices.
关键词： polymer fiber,all-optical modulator,fiber Bragg grating,femtosecond laser micromachining,multi-photon polymerization
更新于2025-09-12 10:27:22
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Femtosecond-laser-written optofluidics in alumino-borosilicate glass
摘要： Femtosecond Laser Irradiation followed by Chemical Etching (FLICE) is a powerful technique for prototyping three-dimensional microfluidic structures in glass. Direct inscription of optical waveguides, by the same femtosecond laser, enables rapid fabrication of optofluidic devices for chemistry or biology applications. As a matter of fact, substrates where FLICE is known as most effective, such as fused silica, are not optimal for laser inscription of high-contrast optical waveguides, thus limiting the potentials of this technology. Here we show that it is possible to apply FLICE also to a commercial alumino-borosilicate glass, where very complex and low-loss photonic circuitry has been demonstrated recently. Besides optimizing the irradiation parameters to achieve hollow structures with high aspect-ratio, we investigate the etching dynamics and the micro-morphology of the etched regions. As a test for the technique, we realize an optofluidic device composed of a microchannel and two intersecting optical waveguides.
关键词： Borosilicate glass,Microfluidics,Femtosecond laser micromachining
更新于2025-09-12 10:27:22