scholarly journals Effect of Substrates on Femtosecond Laser Pulse-Induced Reductive Sintering of Cobalt Oxide Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3356
Author(s):  
Mizue Mizoshiri ◽  
Kyohei Yoshidomi ◽  
Namsrai Darkhanbaatar ◽  
Evgenia M. Khairullina ◽  
Ilya I. Tumkin
Keyword(s):  
Femtosecond Laser ◽  
Cobalt Oxide ◽  
Near Infrared ◽  
Femtosecond Laser Pulses ◽  
Ambient Atmosphere ◽  
Co3o4 Nanoparticles ◽  
Direct Writing ◽  
Polyethylene Naphthalate ◽  
Glass Substrates ◽  
Oxide Composites

Direct writing of cobalt/cobalt oxide composites has attracted attention for its potential use in catalysts and detectors in microsensors. In this study, cobalt-based composite patterns were selectively formed on glass, polyethylene naphthalate (PEN), and polyethylene terephthalate (PET) substrates via the femtosecond laser reductive sintering of Co3O4 nanoparticles in an ambient atmosphere. A Co3O4 nanoparticle ink, including the nanoparticles, ethylene glycol as a reductant, and polyvinylpyrrolidone as a dispersant, was spin-coated onto the substrates. Near-infrared femtosecond laser pulses were then focused and scanned across the ink films to form the patterns. The non-sintered nanoparticles were subsequently removed from the substrate. The resulting sintered patterns were found to be made up of Co/CoO composites on the glass substrates, utilizing various pulse energies and scanning speeds, and the Co/CoO/Co3O4 composites were fabricated on both the PEN and PET substrates. These results suggest that the polymer substrates with low thermal resistance react with the ink during the reductive sintering process and oxidize the patterns more easily compared with the patterns on the glass substrates. Such a direct writing technique of cobalt/cobalt oxide composites is useful for the spatially selective printing of catalysts and detectors in functional microsensors.

scholarly journals Direct Writing of Copper Micropatterns Using Near-Infrared Femtosecond Laser-Pulse-Induced Reduction of Glyoxylic Acid Copper Complex

Micromachines ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 401 ◽  
Author(s):  
Mizue Mizoshiri ◽  
Keiko Aoyama ◽  
Akira Uetsuki ◽  
Tomoji Ohishi
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
Line Width ◽  
Co2 Laser ◽  
Near Infrared ◽  
Glyoxylic Acid ◽  
Ambient Air ◽  
Femtosecond Laser Pulses ◽  
Direct Writing ◽  
Cu Complex

We have fabricated Cu-based micropatterns in an ambient environment using femtosecond laser direct writing to reduce a glyoxylic acid Cu complex spin-coated onto a glass substrate. To do this, we scanned a train of focused femtosecond laser pulses over the complex film in air, following which the non-irradiated complex was removed by rinsing the substrates with ethanol. A minimum line width of 6.1 µm was obtained at a laser-pulse energy of 0.156 nJ and scanning speeds of 500 and 1000 µm/s. This line width is significantly smaller than that obtained in previous work using a CO2 laser. In addition, the lines are electrically conducting. However, the minimum resistivity of the line pattern was 2.43 × 10−6 Ω·m, which is ~10 times greater than that of the pattern formed using the CO2 laser. An X-ray diffraction analysis suggests that the balance between reduction and re-oxidation of the glyoxylic acid Cu complex determines the nature of the highly reduced Cu patterns in the ambient air.

scholarly journals Direct Writing of Cu Patterns on Polydimethylsiloxane Substrates Using Femtosecond Laser Pulse-Induced Reduction of Glyoxylic Acid Copper Complex

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 493
Author(s):  
Nam Phuong Ha ◽  
Tomoji Ohishi ◽  
Mizue Mizoshiri
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
Femtosecond Laser Pulse ◽  
Pulse Energy ◽  
Glyoxylic Acid ◽  
Numerical Aperture ◽  
Scanning Speed ◽  
Femtosecond Laser Pulses ◽  
Direct Writing ◽  
Glass Substrates

We investigate the direct writing properties of copper (Cu) patterns on glass and polydimethylsiloxane (PDMS) substrates using femtosecond laser pulse-induced thermochemical reduction of glyoxylic acid copper (GACu) complex. The films of the GACu complex coated on the substrates were irradiated by focused femtosecond laser pulses using a low numerical aperture of 0.45. Under the same conditions, such as laser scanning speed and pulse energy, the width of the line patterns fabricated on PDMS substrates was larger than that on glass substrates. X-ray diffraction peaks of the patterns on glass substrates corresponded to Cu without significant oxidation. By contrast, although Cu patterns were fabricated on PDMS substrates at a scanning speed of 10 mm/s and pulse energy of 0.49 nJ, Cu2O was also generated under overheating conditions at a scanning speed of 1 mm/s and pulse energy of 0.37 nJ. All the patterns exhibited electrical conductivity. The minimum resistivity of the patterns on PDMS substrates is 1.4 × 10−5 Ωm, which is 10 times higher than that on glass substrates, indicating that microcracks formed by thermal shrinkage of the substrates during the laser irradiation increase the resistivity. This direct Cu writing technique on soft materials is useful for fabricating flexible microdevices.

scholarly journals Regulating disordered plasmonic nanoparticles into polarization sensitive metasurfaces

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shulei Li ◽  
Mingcheng Panmai ◽  
Shaolong Tie ◽  
Yi Xu ◽  
Jin Xiang ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Spatial Resolution ◽  
Metallic Nanoparticles ◽  
Near Infrared ◽  
Optical Memory ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Optical Diffraction ◽  
Plasmonic Nanoparticles ◽  
Direct Laser

Abstract Metasurfaces composed of regularly arranged and deliberately oriented metallic nanoparticles can be employed to manipulate the amplitude, phase and polarization of an incident electromagnetic wave. The metasurfaces operating in the visible to near infrared spectral range rely on the modern fabrication technologies which offer a spatial resolution beyond the optical diffraction limit. Although direct laser writing is an alternative to the fabrication of nanostructures, the achievement of regular nanostructures with deep-subwavelength periods by using this method remains a big challenge. Here, we proposed and demonstrated a novel strategy for regulating disordered plasmonic nanoparticles into nanogratings with deep-subwavelength periods and reshaped nanoparticles by using femtosecond laser pulses. The orientations of the nanogratings depend strongly on the polarization of the femtosecond laser light. Such nanogratings exhibit reflection and polarization control over the reflected light, enabling the realization of polarization sensitive optical memory and color display with high spatial resolution and good chromacity.

scholarly journals Sacrificial-layer free transfer of mammalian cells using near infrared femtosecond laser pulses

PLoS ONE ◽  
2018 ◽  
Vol 13 (5) ◽  
pp. e0195479 ◽  
Author(s):  
Jun Zhang ◽  
Bastian Hartmann ◽  
Julian Siegel ◽  
Gabriele Marchi ◽  
Hauke Clausen-Schaumann ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Mammalian Cells ◽  
Near Infrared ◽  
Sacrificial Layer ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses

scholarly journals Graphene Oxide-Based Silico-Phosphate Composite Films for Optical Limiting of Ultrashort Near-Infrared Laser Pulses

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1638 ◽  
Author(s):  
Adrian Petris ◽  
Ileana Cristina Vasiliu ◽  
Petronela Gheorghe ◽  
Ana Maria Iordache ◽  
Laura Ionel ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Femtosecond Laser ◽  
Near Infrared ◽  
Substrate Surface ◽  
Sol Gel ◽  
Composite Films ◽  
Laser Pulses ◽  
Optical Limiting ◽  
Femtosecond Laser Pulses ◽  
Glassy Matrix

The development of graphene-based materials for optical limiting functionality is an active field of research. Optical limiting for femtosecond laser pulses in the infrared-B (IR-B) (1.4–3 μm) spectral domain has been investigated to a lesser extent than that for nanosecond, picosecond and femtosecond laser pulses at wavelengths up to 1.1 μm. Novel nonlinear optical materials, glassy graphene oxide (GO)-based silico-phosphate composites, were prepared, for the first time to our knowledge, by a convenient and low cost sol-gel method, as described in the paper, using tetraethyl orthosilicate (TEOS), H3PO4 and GO/reduced GO (rGO) as precursors. The characterisation of the GO/rGO silico-phosphate composite films was performed by spectroscopy (Fourier-transform infrared (FTIR), Ultraviolet–Visible-Near Infrared (UV-VIS-NIR) and Raman) and microscopy (atomic force microscopy (AFM) and scanning electron microscopy (SEM)) techniques. H3PO4 was found to reduce the rGO dispersed in the precursor’s solution with the formation of vertically agglomerated rGO sheets, uniformly distributed on the substrate surface. The capability of these novel graphene oxide-based materials for the optical limiting of femtosecond laser pulses at 1550 nm wavelength was demonstrated by intensity-scan experiments. The GO or rGO presence in the film, their concentrations, the composite films glassy matrix, and the film substrate influence the optical limiting performance of these novel materials and are discussed accordingly.

In vivo animal follow-up studies on intrastromal surgery with near-infrared nanojoule femtosecond laser pulses

2005 ◽  
Author(s):  
Baogui Wang ◽  
Iris Riemann ◽  
Karl-Juergen Halbhuber ◽  
Harald Schubert ◽  
Sigrun Kirste ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Near Infrared ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Follow Up Studies
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