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The low-melting glass of Bi2O3-B2O3-SiO2 (BiBSi) system was used for the first time for laser sealing of vacuum glazing. Under the condition of constant boron content, how the structure and properties vary with Bi/Si ratio in low-melting glass was investigated. In addition, the relationships between laser power, low-melting glass solder with different Bi/Si ratios and laser sealing shear strength were revealed. The results show that a decrease in the Bi/Si ratio can cause a contraction of the glass network of the low-melting glass, leading to an increase of its characteristic temperature and a decrease of its coefficient of thermal expansion. During laser sealing, the copper ions in the low-melting glass play an endothermic role. A change in the Bi/Si ratio will affect the valence state transition of the copper ions in the low-melting glass. The absorbance of the low-melting glass does not follow the expected correlation with the Bi/Si ratio, but shows a linear correlation with the content of divalent copper ions. The greater the concentration of divalent copper ions, the greater the absorbance of the low-melting glass, and the lower the laser power required for laser sealing. The shear strength of the low melting glass solder after laser sealing was tested, and it was found that the maximum shear strength of Z1 glass sample was the highest up to 2.67 MPa. [ABSTRACT FROM AUTHOR]

• Laser assist sealing was used to produce entirely glass frit encapsulated DSSCs. • Electrolyte injection holes were micro-structured with laser. • Sealed cells pass the MIL-STD-883, IEC 61646 and ISOS-L-2/3 protocols. • PCE of fully glass sealed cells survived more than 4000 h of ageing. Dye-sensitized solar cells (DSSC) are the fastest-evolving indoor PV technology for long-term wireless power for the internet of things (IoT) devices and wireless sensors. Hermetic encapsulation is crucial for the reliable decoupling of extrinsic and intrinsic degradation factors of DSSCs as well as to protect long-lasting devices against moisture, oxygen ingress, and electrolyte leakage. Encapsulating the edges with glass frits has proven the most durable method of overcoming the device's hermeticity challenge. However, sealing the electrolyte injection holes with glass remained an elusive objective achieved in this study by structuring the glass into a capillary shape and laser-induced fusing the capillary edge. The structured injection hole effectively dissipates heat and thermal stress; when the glass sealing temperature reaches around 1200 °C, the device's cavity does not exceed 50 °C. The method produces sealed devices that passed the MIL-STD-883 helium leakage and the IEC 61646 humidity-freeze tests. After 4336 h of accelerated aging according to ISOS-L-2/3 protocols, entirely glass-sealed DSSCs maintained their photocurrent conversion efficiency (PCE) while conventionally polymer-sealed and partially glass-sealed counterparts exhibit inverse PCE progression, with an average deterioration rate 1.8·10−3 and 2.2·10−3 per day, respectively. Full glass encapsulation allows long-life DSSCs and durable long-term stability certification. Extrinsic degradation is prevented and opens a trustworthy assessment of possible intrinsic degradation factors. [ABSTRACT FROM AUTHOR]

Thermal barrier coatings (TBCs) are used in advanced engines working at higher temperatures. Higher efficiency and performance of gas turbine engines will require careful selection of TBCs. In this study, Ni22Cr10Al1.0Y (Amdry 9625) bond coat and two types of top coat including ceria stabilized zirconia (CSZ) ZrO2-24CeO2-2.5Y2O3) and yttria stabilized zirconia (YSZ) ZrO2-8Y2O3 were deposited on IN 625 by airplasma spraying (APS). The thickness of the duplex ceramic coat based on zirconia was in the range between 350 to 400 μm. The effect of high power Yb:YAG solid state laser at different laser parameters on feature, microstructure and roughness of plasma sprayed and laser sealed coating of multilayer ceria stabilized zirconia/ yttria stabilized zirconia was investigated. Surface roughness has been reduced significantly after laser sealing. The effect of laser process parameters carried out using Taguchi’s L16 orthogonal array design. Minimum roughness can be obtained at moderate power density and longer interaction time with sufficient specific energy to produce complete melting of coating. Characterization and analysis of results was achieved by employing scanning electron microscopy (SEM) , (EDS) and image J analysis. It was found from the results, there were significant improvements in the performance of plasma sprayed coatings after laser sealing due to the reduction of surface coating defects.

Poor strength, infection, leakage, long procedure times, and inflammation limit the efficacy of common tissue sealing devices in surgeries and trauma. Light‐activated sealing is attractive for tissue sealing and repair, and can be facilitated by the generation of local heat following absorption of nonionizing laser energy by chromophores. Here, the inherent ability of biomaterials is exploited to absorb nonionizing, mid‐infrared (midIR) light in order to engender rapid photothermal sealing and repair of soft tissue wounds. In this approach, the biomaterial simultaneously acts as a photothermal convertor as well as a biosealant, which dispenses the need for exogeneous light‐absorbing nanoparticles or dyes. Biomechanical recovery, mathematical modeling, histopathology analyses, tissue strain mapping using digital imaging correlation, and visualization of the biosealant‐tissue interface using hyperspectral imaging indicate superior performance of midIR sealing in live mice compared to conventional sutures and glue. The midIR‐biosealant approach demonstrates rapid sealing of soft tissues, improves cosmesis, lowers potential for scarring, obviates safety concerns because of the nonionizing light used, and allows adoption of a wide diversity of biomaterials. Taken together, the studies demonstrate a novel advance both in biomaterials for surgical sealing along with the use of nonionizing midIR light, with high potential for clinical translation. [ABSTRACT FROM AUTHOR]

PbO-SiO2-Al2O3-B2O3 (PSAB)-based glasses were prepared in order to determine the feasibility for laser sealing in the form of fiber. To reach a high quality of laser sealing, the tuning capability of CuO and Na2CO3 dopant concentration was examined on thermal, thermo-mechanical, and optical properties of glasses. The difference of thermal expansion coefficient was reduced with codoping of 1 wt% CuO-2 wt% Na2CO3 into the PSAB glass system, and it amounted to 0.34 × 10−6/K. The codoped PSAB glass system reached 100% absorption at 810 nm, which corresponds to the wavelength of laser. The glass fiber with a diameter of 180 μm was successfully pulled from the codoped PSAB glass system. The fluorine-doped tin oxide (FTO) glass substrate using the glass fiber was successfully sealed. It presented a crack-free sealed surface with a sealing strength of about 41 MPa. These results indicate that the PSAB-based glass system in the form of fiber is proved as a laser sealing material in packaging systems. [ABSTRACT FROM AUTHOR]

In this paper, we present a new method that is capable of manufacturing microfluidic chips of polymethyl methacrylate (PMMA) rapidly and cheaply. This technique, which we call Tape adhering-Laser Cutting and Sealing Integration (TLCSI), only utilizes a CO2 laser and a piece of double-sided tape to produce a microfluidic chip in several minutes. It only has three main steps. First, the double-sided tape sticks to the surface of a PMMA substrate. Second, the microchannel should be cut on the surface of the double-sided tape. At last, a PMMA cover plate with liquid pools is pressed onto the surface of the double-sided tape and a CO2 laser is used to cut edges of the chip for sealing the chip. We present a qualified microfluidic chip with regular microchannels and sealing strength of 1.2 Mpa. Compared with most current fabrication methods, TLCSI is a quick and cost-effective way to produce microfluidic chips of PMMA. [ABSTRACT FROM AUTHOR]

In order to realize reliable sealing and combination of constructional glass and Kovar alloy, the effects of temperature, holding time, roughness and oxide layers on their wetting property were studied. When the temperature increased from 800℃ to 900℃, the viscosity of liquid glass reduced, so the wetting angle decreased from 69.5° to 31.1°. When the holding time prolonged from 5 min to 40 min at 850℃, the liquid glass had enough time to diffuse under the condition of low viscosity, and the wetting angle increased by 30%. With an increase in roughness of steel sheet surfaces, the barrier increased which was needed to overcome by the liquid glass to spread around. When the roughness value Ra increased from 0.186 μm to 0.563 μm, the wetting angle increased from 46.9° to 69.5°. The oxide layer on the surface of Kovar alloy and the liquid glass had diffusion reaction that could form strong ionic bonds, which increased the wetting property considerably, and the wetting angle could decrease by 23.6%. Therefore, during the actual sealing process, increasing the temperature and holding time, decreasing the roughness of steel sheet surfaces, and steel sheet pretreatment could effectively improve the wetting property of the glass and Kovar alloy.

Inorganic nanomaterials have witnessed significant advances in areas of medicine including cancer therapy, imaging, and drug delivery, but their use in soft tissue repair and regeneration is in its infancy. Metallic, ceramic, and carbon allotrope nanoparticles have shown promise in facilitating tissue repair and regeneration. Inorganic nanomaterials have been employed to improve stem cell engraftment in cellular therapy, material mechanical stability in tissue repair, electrical conductivity in nerve and cardiac regeneration, adhesion strength in tissue approximation, and antibacterial capacity in wound dressings. These nanomaterials have also been used to improve or replace common surgical materials and restore functionality to damaged tissue. We provide a comprehensive overview of inorganic nanomaterials in tissue repair and regeneration, and discuss their promise and limitations for eventual translation to the clinic. [ABSTRACT FROM AUTHOR]

PbO-SiO2-Al2O3-B2O3 (PSAB)-based glasses were prepared in order to determine the feasibility for laser sealing in the form of fiber. To reach a high quality of laser sealing, the tuning capability of CuO and Na2CO3 dopant concentration was examined on thermal, thermo-mechanical, and optical properties of glasses. The difference of thermal expansion coefficient was reduced with codoping of 1 wt% CuO-2 wt% Na2CO3 into the PSAB glass system, and it amounted to 0.34 × 10−6/K. The codoped PSAB glass system reached 100% absorption at 810 nm, which corresponds to the wavelength of laser. The glass fiber with a diameter of 180 μm was successfully pulled from the codoped PSAB glass system. The fluorine-doped tin oxide (FTO) glass substrate using the glass fiber was successfully sealed. It presented a crack-free sealed surface with a sealing strength of about 41 MPa. These results indicate that the PSAB-based glass system in the form of fiber is proved as a laser sealing material in packaging systems.

Abstract: The effect of a 2kW CO2 laser working at different laser and processing parameters on features, microstructure, chemical composition, phases, hardness and fracture toughness of plasma sprayed and laser sealed plasma sprayed coatings of yttria partially stabilized zirconia (YSZ) containing 8wt.% alumina was investigated. The plasma sprayed (YSZ) material containing Al2O3 (YSZAl) showed high hardness and fracture toughness compared with YSZ. Fine cells and dendrites were formed after laser sealing as observed from the upper surface views and transverse sections, respectively. The amount of voids and crack width associated with laser sealing was reduced significantly in YSZAl sealed coatings. The coarse heterogeneous distribution of α-Al2O3 and metastable tetragonal (t′) phases in the plasma sprayed coating is changed to a fine scale duplex structure of t′+α-Al2O3 in the sealed coatings. No cubic (c), transformable tetragonal (t) and monoclinic (m) phases were found for plasma sprayed and laser sealed coatings processed under optimum laser conditions. The rapid solidification caused by laser treatment prevents the transformation of the high temperature c phase to transform to the t and m phases; only the t′ phase is formed by displasive athermal transformation. The fracture toughness of the sealed coatings was observed to increase by a factor of three as compared to that of plasma as-sprayed coating. [Copyright &y& Elsevier]

Abstract: The present paper reports an experimental investigation based on X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and wavelength dispersive spectroscopy (WDS) analyses of phases formed after laser sealing of plasma sprayed coatings of 8.5wt% yttria partially stabilized zirconia (YPSZ). X-ray diffraction and X-ray step-scanning analyses showed that the plasma sprayed and sealed coatings consisted mainly of t′ phase with a very small amount of monoclinic phase (m phase) in the plasma sprayed coatings. It was also found that the small amounts of m and cubic phases (c phase) present in the sealed coatings were dependent on laser processing specific energies (specific energy is equal to laser power/traverse speed x beam diameter). It was also found that rhombohedral (r) phase formed after laser sealing of coatings at higher specific energies. A direct relationship between c/a ratio of transformable tetragonal phase (t phase) produced by thermal treatment of sealed coatings and nontransformable tetragonal phase (t′ phase) and the amount of Yttria was obtained. A new equation was derived, which describes the relationship between Yttria concentration and the c/a ratio of tetragonal phases (t or t′). [Copyright &y& Elsevier]

Long life time and high mechanical strength of organic light emitting diode (OLED) can be achieved via located heating glass frit by near infrared laser exposure. In this paper, influence of laser sealing process on frit hermetical performance is investigated. Rough surface of frit after laser scan may lead to the defect called frit mura, which is proved to decrease the adhesive strength of OLED device. It is found that low power of laser scan can alleviate frit mura. However, the real seal width is small, which is not expected for high hermeticity and mechanical strength. Thus, optimal double laser scan process is presented. [ABSTRACT FROM AUTHOR]

Laser sealing for vacuum plate glass is a key step in developing the cost-effective smart vacuum-glass window for the drive towards net-zero energy buildings. In this paper, the pores, cracks, and interface with laser welding are analyzed in depth using PbO-TiO2-SiO2-RxOy system sealing solder to prepare vacuum flat glass. The microstructure of the sealing layer was analyzed by a BX41M-LED metallographic microscope, and the interfacial bonding characteristics were observed by thermal field emission scanning electron microscopy (SEM). The solder was analyzed by an energy spectrometer, and the influence of laser power, sealing temperature, and sealing speed on the gas holes and the crack sand interface separation of the sealing layer are reported. The results show that when the laser power reached 80 W at the welding speed of 2 mm/s, the bulk solder disappeared to most of the quantity and the sealing surface density was higher, due to which negligible pores and micro cracks were found. Thus, the sealing quality of the sealing layer is considered to be suitable when the temperature of 470 °C was maintained and the solder has 68.93% of Pb and 3.04% Si in the atom fraction to achieve the wet the glass substrate surface whilst improving the bonding quality. [ABSTRACT FROM AUTHOR]