scholarly journals STED Direct Laser Writing of 45 nm Width Nanowire

Micromachines ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 726 ◽  
Author(s):  
Xiaolong He ◽  
Tianlong Li ◽  
Jia Zhang ◽  
Zhenlong Wang
Keyword(s):  
Laser Power ◽  
Excitation Wavelength ◽  
Direct Laser Writing ◽  
Laser Writing ◽  
Single Nanowire ◽  
Direct Laser ◽  
Pentaerythritol Triacrylate ◽  
Excitation Laser ◽  
Focus Spot ◽  
Excitation Laser Power

Controlled fabrication of 45 nm width nanowire using simulated emission depletion (STED) direct laser writing with a rod-shape effective focus spot is presented. In conventional STED direct laser writing, normally a donut-shaped depletion focus is used, and the minimum linewidth is restricted to 55 nm. In this work, we push this limit to sub-50 nm dimension with a rod-shape effective focus spot, which is the combination of a Gaussian excitation focus and twin-oval depletion focus. Effects of photoinitiator type, excitation laser power, and depletion laser power on the width of the nanowire are explored, respectively. Single nanowire with 45 nm width is obtained, which is λ/18 of excitation wavelength and the minimum linewidth in pentaerythritol triacrylate (PETA) photoresist. Our result accelerates the progress of achievable linewidth reduction in STED direct laser writing.

Fabrication of gold micro/nanostructures by femtosecond laser direct writing and chemical etching

2014 ◽  
Vol 23 (04) ◽  
pp. 1450048 ◽  
Author(s):  
Hongxin Zhang ◽  
Tianqing Jia ◽  
Kan Zhou ◽  
Jukun Liu ◽  
Donghai Feng ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Chemical Etching ◽  
Ethanol Solution ◽  
Photon Absorption ◽  
Direct Laser Writing ◽  
Direct Writing ◽  
Laser Writing ◽  
Two Photon Absorption ◽  
Direct Laser ◽  
Pentaerythritol Triacrylate

In this paper, we report gold micro/nanostructures fabricated by a method called lithographically patterned nanostructure by chemical etching (LPNCE). In the LPNCE method, the photoresist layer, composed of pentaerythritol triacrylate (PETA, monomer) and isopropyl thioxanthone (ITX, photoinitiator), is dropped on gold film, and subsequently polymerized via two-photon absorption of 800 nm femtosecond laser. Micro/nanostructures are fabricated by the direct laser writing. The unpolymerized photoresist is washed by isopropanol, and the exposed gold is dissolved by KI 3 aqueous solution. Finally, polymers are removed by NaOH ethanol solution. Arbitrary 2D gold micro/nanostructures can be fabricated quickly by the direct laser writing and chemical etching method. The good electro-conductibility of these micro/nanostructures guarantees wide applications in micro-electronic devices, plasmonics and biosensors, etc.

scholarly journals On-chip Direct Laser Writing of PAN-based Carbon Supercapacitor Electrodes

2021 ◽  
Author(s):  
Andreas Hoffmann ◽  
Pablo Jiménez-Calvo ◽  
Volker Strauss ◽  
Alexander Kühne
Keyword(s):  
Laser Power ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Carbon Electrodes ◽  
Direct Laser Writing ◽  
Laser Writing ◽  
Printed Circuit ◽  
Direct Laser ◽  
On Chip

We report carbonization of polyacrylonitrile by direct laser writing to produce microsupercapacitors directly on-chip. We demonstrate the process by producing interdigitated carbon finger electrodes directly on a printed circuit board, which we then employ to characterize our supercapacitor electrodes. By varying the laser power, we are able to tune the process from carbonization to material ablation. This allows to not only convert pristine polyacrylonitrile films into carbon electrodes, but also to pattern and cut away non-carbonized material to produce completely freestanding carbon electrodes. While the carbon electrodes adhere well to the printed circuit board, non-carbonized polyacrylonitrile is peeled off the substrate. We achieve specific capacities as high as 260 µF/cm2 in a supercapacitor with 16 fingers.

One Photon 3D Polymerization via Direct Laser Writing

2018 ◽  
Vol 941 ◽  
pp. 2142-2147
Author(s):  
Federico Mochi ◽  
Fabio de Matteis ◽  
Paolo Prosposito ◽  
Luca Burratti ◽  
Roberto Francini ◽  
...  
Keyword(s):  
Excitation Wavelength ◽  
Direct Laser Writing ◽  
Depth Of Focus ◽  
3D Scaffold ◽  
Laser Writing ◽  
Polyethylene Glycol Diacrylate ◽  
Glycol Diacrylate ◽  
Direct Laser ◽  
Fine Control ◽  
Laser Stereolithography

A way to produce 3D scaffold is via laser stereolithography. We propose a method of direct laser writing for micro-stereolithography in which we use as light source a low power blue diode laser with a wavelength of 448nm. The material chosen for scaffold fabrication is a polyethylene glycol diacrylate (PEGDA) solution at concentration of 75% in ethanol. We chose a short PEGDA molecule with a molecular weight of 575 g/mol, in order to obtain a better control over the polymerization. We used Irgacure 819 as photoinitiator to initiate the photopolymerization. The absorption of the Irgacure 819 almost drops to zero at the excitation wavelength, so the efficiency of the photopolymerization is strongly reduced. Since the intensity of the light reduces by a factor 5 within a penetration depth, equal to the depth of focus of the optical system, we achieve a fine control of the vertical and lateral photopolymerization of the solution. The threshold for effective polymerization is not reached outside that region.

Fabrication of 3D Photoresist Structure for Artificial Capillary Blood Vessel

2013 ◽  
Vol 25 (4) ◽  
pp. 673-681
Author(s):  
Azrena Abu Bakar ◽  
◽  
Masahiro Nakajima ◽  
Chengzhi Hu ◽  
Hirotaka Tajima ◽  
...  
Keyword(s):  
Laser Power ◽  
Numerical Aperture ◽  
Direct Laser Writing ◽  
Combined Model ◽  
Laser Writing ◽  
Kidney Glomerulus ◽  
Direct Laser ◽  
Capillary Blood Vessel ◽  
Different Diameters ◽  
Fabrication Time

We propose a new method for fabricating artificial capillaries using direct laser writing. IP-L and Ormocomp are tested as photoresist materials. Three different microstructures were fabricated from IP-L: a porous hollow pipe microstructure, a 3 × 3 array of twig microstructures, and an array of hollow twig microstructures. Porous hollow pipe microstructures of different diameters were fabricated from Ormocomp, a biocompatible photoresist. These designs resemble capillaries. IP-L and Ormocomp fabrication parameters, such as laser power, numerical aperture, fabrication time, and fabrication model, are compared. Fabrication time is related to the fabrication model chosen during the direct laser writing process. Combined model fabrication is recommended over solid model fabrication because it results in shorter fabrication time and a more robust microstructure that is more likely to maintain its shape on the substrate after development. Laser power is another important parameter controlling fabrication. IP-L fabrication withstands up to 20 mW of laser power, unlike Ormocomp microstructures, which require laser power of less than 18 mW. IP-L and Ormocomp photoresist stiffness is also evaluated. The fabrication of artificial capillaries is important in developing vascular simulators that enable researchers to understand, for example, blood pressure in the kidney glomerulus.

scholarly journals Controlled formation of metallic tellurium nanocrystals in tellurite glasses using femtosecond direct laser writing

2021 ◽  
Author(s):  
Renato Grigolon Capelo ◽  
Juliana M.P. Almeida ◽  
Douglas Faza Franco ◽  
Gael Yves Poirier ◽  
Cleber Renato Mendonça ◽  
...  
Keyword(s):  
Tellurite Glasses ◽  
Direct Laser Writing ◽  
Laser Writing ◽  
Direct Laser

scholarly journals Femtosecond direct laser writing of gold nanostructures by ionic liquid assisted multiphoton photoreduction

2013 ◽  
Vol 3 (10) ◽  
pp. 1660 ◽  
Author(s):  
Wei-Er Lu ◽  
Yong-Liang Zhang ◽  
Mei-Ling Zheng ◽  
Yan-Peng Jia ◽  
Jie Liu ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Gold Nanostructures ◽  
Direct Laser Writing ◽  
Laser Writing ◽  
Direct Laser
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