Microstructuring of polymer films by femtosecond pulses through optically trapped polystyrene microspheres

Астафьев, А. А.; Shakhov, Alexander N.; Sarkisov, O. M.; Надточенко, В. А.

doi:10.1070/qe2013v043n04abeh015114

Cited by 3 publications

(3 citation statements)

References 22 publications

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“…Minimal obtained crater dimensions are depicted in Figure . Craters had a nearly circular shape, although femtosecond pulse linear polarization ( E along the OX -axis) tends to cause ellipticity of the near-field zone and the crater shape. , When femtosecond pulses were focused without microspheres and filled the whole input pupil of the objective lens (40× 0.75 N.A. ), craters of a similar depth had FWHM of about 150 nm (Figure S2).…”

Section: Resultsmentioning

confidence: 99%

Femtosecond Nanostructuring of Glass with Optically Trapped Microspheres and Chemical Etching

Shakhov

Astafiev

Гулин

et al. 2015

ACS Appl. Mater. Interfaces

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Laser processing with optically trapped microspheres is a promising tool for nanopatterning at subdiffraction-limited resolution in a wide range of technological and biomedical applications. In this paper, we investigate subdiffraction-limited structuring of borosilicate glass with femtosecond pulses in the near-field of optically trapped microspheres combined with chemical postprocessing. The glass surface was processed by single laser pulses at 780 nm focused by silica microspheres and then subjected to selective etching in KOH, which produced pits in the laser-affected zones (LAZs). Chemical postprocessing allowed obtaining structures with better resolution and reproducibility. We demonstrate production of reproducible pits with diameters as small as 70 nm (λ/11). Complex two-dimensional structures with 100 nm (λ/8) resolution were written on the glass surface point by point with microspheres manipulated by optical tweezers. Furthermore, the mechanism of laser modification underlying selective etching was investigated with mass spectrum analysis. We propose that the increased etching rate of laser-treated glass results from changes in its chemical composition and oxygen deficiency.

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Section: Resultsmentioning

confidence: 99%

Femtosecond Nanostructuring of Glass with Optically Trapped Microspheres and Chemical Etching

Shakhov

Astafiev

Гулин

et al. 2015

ACS Appl. Mater. Interfaces

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“…[ 14,15 ] PS can also be structured using mold‐free methods like direct microstructuring, laser‐based structuring or micromilling. [ 16 ] The surface and edge roughness of the produced structures through these processes (R a between 30 to 70 nm), [ 17 ] strongly depends on the milling tool used or the parameter of voxel‐based structuring. [ 18,19 ] “Shrinky dink” microfluidics has been introduced using an expanded PS sheet, which is structured using milling and subsequently shrunk to the micrometer‐scale using a heat treatment.…”

Section: Introductionmentioning

confidence: 99%

A Polystyrene Photoresin for Direct Lithography of Microfluidic Chips

Corredor

Mayoussi

Luitz

et al. 2022

Adv Materials Technologies

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Polystyrene (PS) is the material of choice for many medical, biological, and biomedical applications given its advantageous properties such as high biocompatibility, optical transparency, and the possibility to shape PS using high‐throughput manufacturing methods at low production costs. Due to its properties, PS is an interesting material for the fabrication of microfluidic systems. In microfluidics, rapid prototyping is of high importance for testing new chip layouts and designs during the product development with the aim of significantly accelerating the manufacturing. To allow transitioning and thus significantly faster translation from research to scalable manufacturing, it would be ideal if the same material could be used throughout the whole design pipeline. However, rapid prototyping and high‐resolution shaping of PS, especially on the micron scale, is still limited. In this work,a novel photocurable polystyrene photoresin, is presented which can be shaped using direct optical lithography. Using this PS photoresin, microfluidic chips with feature sizes down to 50 µm and a high optical transparency can be fabricated. The cured PS photoresin shows comparable surface and material properties to commercial PS. This method will enable researchers in the medical, biological and biomedical fields to produce suitable PS structures with commercial equipment.

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“…Enhancement of electromagnetic field intensity of the laser pulse occurs in the near field of organelles. Using our method of calculating the intensity of field strength [6,7], the coefficient of field intensity enhancement was obtained, which appeared to be close to 5, and the size of the near-field zone less than 0.5 μm. Intensity enhancement in the organelle near field may lead to the cytoplasm rupture by a focused laser pulse with formation of a bubble.…”

Section: μMmentioning

confidence: 99%

Determining the Range of Noninvasive Near-Infrared Femtosecond Laser Pulses for Mammalian Oocyte Nanosurgery

Osychenko¹,

Tochilo²,

Astafiev³

et al. 2017

Sovrem Tehnol Med

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The aim of the investigation was to determine a noninvasive range of near-infrared femtosecond laser pulse exposure for mouse oocyte intracellular nanosurgery and to estimate oocyte developmental competence in vitro depending on pulse energy and total exposure time.Materials and Methods. The model object was a preovulatory germinal vesicle mouse oocyte. Femtosecond laser radiation with a central wavelength of 780 nm was utilized in two modes: 1) single pulses with 30 fs duration and pulse energy up to 100 nJ; 2) trains of pulses with 100 fs duration, 80 MHz repetition rate (12.5 ns between pulses) and pulse energy from 0.5 to 2 nJ; total duration of the pulse trains ranged from 15 to 60 ms. Radiation was focused by a microscope objective lens (60×, 0.7 NA). Oocytes were cultured to the metaphase of the second meiotic division, which was used as invasiveness criteria. This stage was detected by polar bodies and metaphase plate formation.Results. The threshold of invasiveness was determined for a single femtosecond pulse exposure. Cytoplasmic membrane rupture and cell disruption occurred under the exposure of a single 30 fs pulse with 100 nJ energy. The cytoplasm and nucleus exposure to femtosecond pulse trains did not induce permanent damage to the oocytes. The rate of gas-vapor bubble formation was measured after the action of pulse trains on the cytoplasm and nucleus chromatin of mammalian oocytes. The pulse energy of 1 nJ is a threshold value for bubble formation in the cytoplasm, and 2 nJ in the nucleus. Exposure to laser pulse trains with 80 MHz repetition rate and 100 fs duration didn't change oocyte ability to achieve metaphase II stage within the studied range of pulse energies and pulse train durations.Conclusion. Surgery with femtosecond pulse trains at 80 MHz repetition rate and pulse energy not more than twice as high as the threshold of cavitation or vapor bubble formation does not affect oocyte development to the metaphase II stage. Femtosecond laser nanosurgery can be regarded as a minimally invasive method of intracellular surgery within the investigated range of pulse energies and exposure times.Key words: intracellular surgery; laser surgery; femtosecond laser; preovulatory oocytes.For contacts: Alina A. Osychenko, e-mail: alina.chemphys@gmail.com Laser Nanosurgery of Mammalian OocytesNanosurgical operations on the cells and embryos using femtosecond lasers with the wavelength in the near-infrared range is a challenging direction of modern biophotonics. The near-infrared range is in the region of biotissue transparency: it is not absorbed either by the water or organic substances of the cell (proteins, lipids, nucleic acids, carbohydrates) [1]. A high localization of the femtosecond pulse action in the area of laser beam waist (about 10 femtoliters volume) allows one to perform operations inside the cell/embryo on a separate organelle leaving intact the cell environment and causing no damage to the outer membrane [1][2][3]. Non-linear optical absorption of laser pulse energy by the cell material...

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Microstructuring of polymer films by femtosecond pulses through optically trapped polystyrene microspheres

Cited by 3 publications

References 22 publications

Femtosecond Nanostructuring of Glass with Optically Trapped Microspheres and Chemical Etching

Femtosecond Nanostructuring of Glass with Optically Trapped Microspheres and Chemical Etching

A Polystyrene Photoresin for Direct Lithography of Microfluidic Chips

Determining the Range of Noninvasive Near-Infrared Femtosecond Laser Pulses for Mammalian Oocyte Nanosurgery

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