Laser-induced Deposition Research Articles

Tunnel/jump electroconductivity in the laser-induced nanocluster structures with controlled topology

By method of laser-induced thermal deposition of colloidal particles laser we have produced the metallic granular films for which the ability to control the change in its electrical properties does exist by variation of the topology for the system. The quantum states verification in cluster metallic structures by jump/tunneling electroconductivity and possible mechanisms for its implementation are considered in experiment and theory. The granular conductivity specificity has been under study. The current–voltage characteristics behavior has been measured for a gold (Au) and Au-carbyne clustered film. Two associated mechanisms for electroconductivity occur in the case, i.e. tunnel transition for electrons and electron activation in the frames of the shell model for a cluster system, in dependence on the nanostructure topology.

Non-enzymatic sensors based on in situ laser-induced synthesis of copper-gold and gold nano-sized microstructures

The synthesis of conductive gold and copper-gold microstructures with high developed surface based on the method of laser-induced metal deposition from solution was developed. The topology and crystallization phase of these structures were observed by means of scanning electron microscopy and X-ray diffraction, respectively. The electrochemical properties of the synthesized materials were investigated using cyclic voltamperometry and amperometry. According to the obtained results, it was found out that copper-gold microstructures demonstrate a linear dependence of Faraday current vs. concentration from 0.025 to 5µM for D-glucose and from 0.025 to 10µM for hydrogen peroxide. In turn, gold deposit exhibits a linear dependence of Faraday current vs. concentration from 0.025 to 50µM for D-glucose and from 0.025 to 1µM for hydrogen peroxide. Moreover, the synthesized materials reveal low detection limits (0.025µM) with respect to the aforementioned analytes, which is quite promising for their potential application in design and fabrication of new non-enzymatic biosensors.

Sensory properties of copper microstructures deposited from water-based solution upon laser irradiation at 532 nm

The simple and cheap method for fabrication of micro-sized electrochemical electrodes was proposed. The porous copper microstructures synthesized by laser-induced metal deposition technique were used as an indicator electrode, whereas a bulk polycrystalline copper with similar geometric parameters was used as an etalon electrode. The electrochemical properties of these electrodes were studied by cyclic voltammetry and impedance spectroscopy. The surface of the deposited copper structures was investigated by X-ray photoelectron spectroscopy and atomic force microscopy. An analytical response of the fabricated copper electrode is 15 times higher than those observed for a pure bulk copper. A study of sensory characteristics for hydrogen peroxide and d-glucose detection showed that the value of Faraday current at the fabricated copper electrode is 2–2.5 orders of magnitude higher than for etalon one.

Analysis of the factors affecting the morphology of the product of laser deposition of metals

Using an example of a laser-induced deposition of metals from a solution onto a substrate, we have considered a problem of controlling material nanostructuring. Equations describing the kinetics of deposition process are proposed.

High rate in situ laser-induced synthesis of copper nanostructures performed from solutions containing potassium bromate and ethanol.

The synthesis of copper nanostructures from solutions in the presence of oxidizing additives on the surface of opaque and transparent substrates was performed upon laser irradiation at 532nm. Organic alcohols such as ethanol and ethylene glycol were used as the reducing agents whereas potassium bromate was employed in order to demonstrate the influence of inorganic oxidizing additives on the process of the copper laser-induced synthesis from aqueous solutions. The presence of these additives increases the copper deposition rate during the synthesis which is a grand challenge of implementation of laser-induced liquid-phase metal deposition technique. The scanning electron microscopy, energy-dispersive analysis and impedance spectroscopy reveal that the synthesized copper structures from solutions containing potassium bromate composed of densely agglomerated nanocrystals.

Local Surface Modification of Quartz Glass by the Laser-Induced Reactive Deposition of Carbon Clusters

Local Surface Modification of Quartz Glass by the Laser-Induced Reactive Deposition of Carbon Clusters

The Second CGHC Motif of Protein Disulfide Isomerase Mediates Thrombosis

Protein disulfide isomerase (PDI) catalyzes thiol-disulfide exchange reactions that are critical for protein function. PDI has two distinct CGHC redox-active sites, but nothing is known about which site is important in physiologic reactions including thrombosis. To study the role of PDI and its active sites in thrombosis we used two genetically-modified models, Mx1-Cre/PDIfl/fl mice with blood cells and vessel wall cells lacking PDI, and transgenic PDI(ss-oo) mice with PDI lacking the second CGHC active site. Using laser-induced cremaster arteriole injury fibrin deposition was decreased in both mouse models. Both mouse models showed attenuation of platelet accumulation using laser arterial injury and FeCl3-induced mesenteric artery injury. The defects in fibrin deposition and platelet accumulation were rescued by infusion of recombinant PDI(oo-ss) containing only a functional second active site, confirming the second active site of PDI was critical for both fibrin formation and platelet accumulation. In vitro studies showed that platelet aggregation depended on the second CGHC motif of PDI, and that binding of PDI protein to platelets depended on the presence of the αIIbβ3 integrin. Studies on platelet secretion revealed that P-selectin expression and ATP release were dependent on a functional second active site of PDI. Treatment of the platelets with eptifibatide did not affect P-selectin expression. Together these findings suggest the second active of PDI catalyzes a reaction in αIIbβ3 supporting platelet aggregation and a reaction in a non-αIIbβ3 substrate supporting secretion. In vivo studies on coagulation showed that PDI infusion rescued fibrin formation in eptifibatide-treated mice in which platelet accumulation was completely blocked, suggesting that PDI directly contributes to activation of coagulation. In summary, our results indicate that the second CGHC active site of PDI has a role in platelet function and coagulation. Targeting this site may have a dual inhibitory effect on thrombosis by decreasing both platelet and fibrin accumulation. DisclosuresNo relevant conflicts of interest to declare.

Numerical Simulations on the Effect and Efficiency of Long Linear Energy Deposition Ahead of a Supersonic Blunt Body: Toward a Laser Spike

The effect of single or repetitive linear energy depositions in front of a supersonic blunt body is computed using the CEDRE flow solver. The CFD Code models the effect of a laser-induced energy deposition, as obtained for example using the long filaments created by a femtosecond laser. Single energy depositions show that significant transient drag reductions are obtained, due to the interaction of the heated core, created by the energy release, with the bow shock. When the deposition is repeated, cumulative effects are important and quasi-steady or unsteady flow regimes are obtained, depending on the power and repetition frequency. This behavior is similar to that obtained with supersonic spiked blunt bodies, acting like a laser spike. This system can lead to 15%-20% fuel savings, depending on the energy deposition efficiency.

Aluminum Chloride Reveals the Catalytic Activity Towards Laser-Induced Deposition of Copper from Water-Based Solutions

Aluminum Chloride Reveals the Catalytic Activity Towards Laser-Induced Deposition of Copper from Water-Based Solutions

Annealing effect: Controlled modification of the structure, composition and plasmon resonance of hybrid Au–Ag/C nanostructures

Here we present a novel approach to the synthesis of hybrid Au–Ag/C nanoparticles (NPs) which were found to be carbon nanospheres containing dispersed Au–Ag bimetallic nanoparticles (1–5nm). The Au–Ag/C NPs were obtained by laser-induced liquid phase deposition from solutions of supramolecular complex. It was revealed that subsequent annealing procedure of Au–Ag/C NPs at various temperatures over the range 100–600°C allows variation and directed control of NPs’ morphology and composition (relative contents of principal components). For nanoscale carbon material the critical evaporation temperature was found to be about 300°C, while for Ag and Au components – 500°C and 600°C accordingly. The morphology and composition variation makes possible tuning of the surface plasmon resonance characteristics that opens an efficient way of the NPs’ functional properties control, like for example Surface-Enhanced Raman Scattering (SERS). It was found that the obtained hybrid Au–Ag/C NPs display pronounced SERS activity with the enhancement factor (EF) ca. 105.

Preparation of surface-enhanced Raman scattering(SERS)-active optical fiber sensor by laser-induced Ag deposition and its application in bioidentification of biotin/avidin

A surface-enhanced Raman scattering(SERS) optical fiber sensor was prepared by the laser-induced deposition of Ag nanoparticle membrane on a silica optical fiber tip, which was applied to the real time SERS spectral monitoring on the biorecognition of biotin/avidin. The bioidentification of biotin/avidin was carried out through a indirect method, in which the bioidentification is based on the SERS response signal of a labeled dye(Atto610) after its fluorescence has been quenched totally by the deposited Ag nanoparticle membrane. By SERS monitoring the bioidentification process of biotin/avidin, it has been found that this recognition process is finished in 40 min. The lowest detection concentration of biotin is 1.0×10−7 mg/mL. This research is promising in the application of immunoassays on line and in vivo.

Dark pulses and harmonic mode locking in graphene-based passively mode-locked Yb3+-doped fiber laser with all-normal dispersion cavity

Graphene has recently been proposed as an attractive material in saturable absorption (SA) applications due to its broad operation range, low saturation power, easy fabrication, high reliability, and quick recovery time. In this paper, we use laser-induced deposition to prepare graphene saturable absorber, and apply it in a mode-locked all-normal-dispersion (ANDi) Yb-doped fiber laser to experimentally investigate different operational states. By adjusting a polarization controller (PC) and the pump power, bright pulses, dark-bright pulse pairs and their second-harmonic pulses, as well as dark pulses and their second, third-harmonic pulses can all be obeserved. In particular, it is the first time to our knowledge to report on the formation of dark-bright pulse pairs, dark pulses and their harmonic mode locking (HML) counterparts in graphene-based passively mode-locked Yb-doped fiber laser with ANDi cavity. Accoding to simulation, the main causes of these pulses are different cavity nonlinear effects which result from the fiber mode-lock members including graphene. Bright pulses, dark pulses and dark-bright pulse pairs are determined both by the laser structure and their own initial signals. Bright pulse harmonic generation is ascribed to the noise gains which form new components. However, it is found that the multiple-time repetition rate of dark pulses is a result of square pulse splitting of each component. This consequence may be of potential application in new type mode-locked fiber lasers.

Laser-induced deposition of nanostructured copper microwires on surfaces of composite materials

Microelectronics industry is growing fast and the rate of new devices' development increases every year. Therefore, methods for simple and high-precision metal coating on dielectrics are needed. Existing methods do not allow performing the high-precision metal deposition without using photomasks, while making a photomask for each prototype is a long and expensive process. One of the methods of maskless metal deposition is laser-induced chemical liquid-phase deposition (LCLD). In this work we show the effect of substrate surface type on a result of LCLD. Deposited copper structures were characterized by SEM, EDX and impedance spectroscopy. The results show that laser-induced copper deposition is highly affected by the surface being a homogeneous or composite material. It was found that the deposits with low resistivity and high quality metal localization mostly appear on the two-phase surfaces. In contrast, deposits on one-phase surfaces exhibited poor topology of copper material. Statistical modeling was involved to describe this phenomenon.

Experimental characterizations of burr deposition in Nd:YAG laser drilling: a parametric study

Laser machining on metals is based on heat effect on most occasions, so resolidified material can hardly be avoided. In laser drilling, the laser-induced burr deposition on the exit rim is one of the resolidified materials, and the amount of which directly affects the hole quality, but unfortunately it has not been especially studied in the past. The objective of this work is to study the experimental characterizations of burr deposition on different drilling conditions, to shed light upon the mechanism of burr formation in laser trepan drilling, and to minimize it under the available experimental conditions. The effects of seven processing parameters are respectively studied by single-factor experiments, and the optimum combination of parameters which yields the minimum burr is determined by the Taguchi method. The final drilling result shows that the burr deposition has largely been reduced.

Bioprinting of artificial blood vessels: current approaches towards a demanding goal.

Free-form fabrication techniques, often referred to as '3D printing', are currently tested with regard to the processing of biological and biocompatible materials in general and for fabrication of vessel-like structures in particular. Such computer-controlled methods assemble 3D objects by layer-wise deposition or layer-wise cross-linking of materials. They use, for example, nozzle-based deposition of hydrogels and cells, drop-on-demand inkjet-printing of cell suspensions with subsequent cross-linking, layer-by-layer cross-linking of synthetic or biological polymers by selective irradiation with light and even laser-induced deposition of single cells. The need of vessel-like structures has become increasingly crucial for the supply of encapsulated cells for 3D tissue engineering, or even with regard to future application such as vascular grafts. The anticipated potential of providing tubes with tailored branching geometries made of biocompatible or biological materials pushes future visions of patient-specific vascularized tissue substitutions, tissue-engineered blood vessels and bio-based vascular grafts. We review here the early attempts of bringing together innovative free-form manufacturing processes with bio-based and biodegradable materials. The presented studies provide many important proofs of concepts such as the possibility to integrate viable cells into computer-controlled processes and the feasibility of supplying cells in a hydrogel matrix by generation of a network of perfused channels. Several impressive results in the generation of complex shapes and high-aspect-ratio tubular structures demonstrate the potential of additive assembly methods. Yet, it also becomes obvious that there remain major challenges to simultaneously match all material requirements in terms of biological functions (cell function supporting properties), physicochemical functions (mechanical properties of the printed material) and process-related (viscosity, cross-linkability) functions, towards the demanding goal of biofabricating artificial blood vessels.

ArF excimer laser-induced deposition of Ag/C nanocomposite thin films in the presence of n-Hexane

Abstract Ag/C nanocomposite thin films with different Ag/C molar ratios have been prepared using ArF excimer laser-induced ablation process and silver target under n-Hexane atmosphere. The morphology, crystal structure and composition of as-deposited Ag/C nanocomposite thin films were investigated with high resolution electronic microscopic techniques (including scanning electron microscopy and transmission electron microscopy) and energy-dispersive X-ray spectroscopy, respectively. Laser Raman spectroscopy and Fourier transform infrared spectroscopy techniques were also applied to characterize the final carbonaceous products generated from n-Hexane under laser ablation process. The optical emission of the plume caused by the interaction between excimer laser and silver target in the presence of n-Hexane was studied to understand the possible reaction process. The UV–vis absorption of as-deposited Ag/C thin films, which is attributed to the surface plasmonic excitation, was also investigated in the present work.

Laser Induced Chemical Deposition of Ferrihydrite Nanotubes: Exploring Growth Rate and Crystal Structure

This paper is one of three papers exploring and confirming a novel high rate nanomanufacturing method using laser to induce and accelerate chemical synthesis and deposition of nanotubes. We have shown elsewhere that the growth rate of SnO2 nanotubes by this method is a few orders faster than that by the state of the art electrochemical deposition method, the growth rate of the nanotubes is favorably affected by increasing the laser power under a constant number of scanning passes, and the process can grow nanotubes coalesced from ultrasmall particle size as small as 2 nm (Liu and Liu, 2013, "Laser Induced Chemical Solution Deposition of Nanomaterials: A Novel Process Demonstrated by Manufacturing SnO2 Nanotubes," Manuf. Lett., 1(1), pp. 42–35). In the second paper, we have shown that this novel method is generic, demonstrated by synthesizing various metal oxide and sulfide nanotubes (Liu and Liu, "Laser-Induced Solution Synthesis and Deposition: A Generic Method to Make Metal Chalcogenide Nanotubes at High Rate With High Consistency," J. Nanoeng. Nanosyst. (accepted)). Since the performance and properties of nanomaterials are highly dependent on its structure, we explore here how the basic processing variables affect the growth rate and crystal size. Our initial finding is that (1) the growth rate can be increased by increasing the pH value of the solution, resulting in little change on the crystal size and (2) the crystal size of the manufactured ferrihydrite nanotube arrays can be controlled by changing laser scanning passes. We found the increase of the pH value from 1.33 to 2.16 almost tripled the growth rate of ferrihydrite nanotubes, while the crystal size remained little changed as revealed by the transmission electron microscopy studies. However, increasing the number of laser scanning passes at a given power could coarsen the ferrihydrite nanocrystals. The crystal structure of the nanotubes could be converted to haematite by dry furnace annealing. These initial findings demonstrated the capability and controllability of the novel process.

Laser-Induced Copper Deposition from Solution: Removing the Thermodynamic Restrictions

s. The study showed that organic alcohols with 1,2,3,5,6 hydroxyl groups can be used as reducing agents for laser-induced copper deposition from solutions (LCLD).Multiatomic alcohols, sorbitol, xylitol, and glycerol, are shown to be effective reducing agents for performing LCLD at glass-ceramic surfaces unless they are weak reductants. Hypothesis of 2-photon photoeffect during laser induced copper deposition was discussed. Using the described dechnique one can obtain high-conductivity copper micro wires on dielectric surfaces for microelectronics and sensor applications

Laser-Induced Copper Deposition with Weak Reducing Agents

Laser-Induced Copper Deposition with Weak Reducing Agents

LCLD Laser Processing Technology for Microelectronics Printed- circuit Boards of New Generation

Abstract This paper has dealt with the formation mechanism of nanosized metal coatings on dielectrics; the coatings were produced using laser-induced deposition from liquid phase. A diode-pumped solid-state (DPSS) laser (532 nm) was used in the deposition experiments. The laser power varied from 500 to 1500 mW with the single scanning rate up to 50 μm/s. The deposited copper structures were studied by the scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis (EDX) methods. The main attention in the paper was given to studying the effect of laser light pressure on the solid nanoparticles. There was constructed the qualitative model of nanoparticles formation during salt film decomposition at the hetero-phase “gas/liquid” border. The radiation energies thermalized by nanoparticles were calculated, and assessment of their temperature was found.