scholarly journals Collagen/Chitosan Functionalization of Complex 3D Structures Fabricated by Laser Direct Writing via Two-Photon Polymerization for Enhanced Osteogenesis

2020 ◽  
Vol 21 (17) ◽  
pp. 6426
Author(s):  
Irina Alexandra Păun ◽  
Cosmin Cătălin Mustăciosu ◽  
Roxana Cristina Popescu ◽  
Bogdan Ştefăniţă Călin ◽  
Mona Mihăilescu
Keyword(s):  
Bone Substitutes ◽  
Staining Intensity ◽  
Dip Coating ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Alizarin Red ◽  
Biological Assays ◽  
3D Structures ◽  
Two Photon ◽  
Osteogenic Effect

The fabrication of 3D microstructures is under continuous development for engineering bone substitutes. Collagen/chitosan (Col/CT) blends emerge as biomaterials that meet the mechanical and biological requirements associated with bone tissue. In this work, we optimize the osteogenic effect of 3D microstructures by their functionalization with Col/CT blends with different blending ratios. The structures were fabricated by laser direct writing via two-photons polymerization of IP-L780 photopolymer. They comprised of hexagonal and ellipsoidal units 80 µm in length, 40 µm in width and 14 µm height, separated by 20 µm pillars. Structures’ functionalization was achieved via dip coating in Col/CT blends with specific blending ratios. The osteogenic role of Col/CT functionalization of the 3D structures was confirmed by biological assays concerning the expression of alkaline phosphatase (ALP) and osteocalcin secretion as osteogenic markers and Alizarin Red (AR) as dye for mineral deposits in osteoblast-like cells seeded on the structures. The structures having ellipsoidal units showed the best results, but the trends were similar for both ellipsoidal and hexagonal units. The strongest osteogenic effect was obtained for Col/CT blending ratio of 20/80, as demonstrated by the highest ALP activity, osteocalcin secretion and AR staining intensity in the seeded cells compared to all the other samples.

scholarly journals Advanced Micro-Actuator/Robot Fabrication Using Ultrafast Laser Direct Writing and Its Remote Control

2020 ◽  
Vol 10 (23) ◽  
pp. 8563
Author(s):  
Sangmo Koo
Keyword(s):  
Three Dimensional ◽  
Processing Technique ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Precise Control ◽  
Two Photon ◽  
Non Invasive ◽  
Acoustic Control ◽  
Fs Laser ◽  
Invasive Control

Two-photon polymerization (TPP) based on the femtosecond laser (fs laser) direct writing technique in the realization of high-resolution three-dimensional (3D) shapes is spotlighted as a unique and promising processing technique. It is also interesting that TPP can be applied to various applications in not only optics, chemistry, physics, biomedical engineering, and microfluidics but also micro-robotics systems. Effort has been made to design innovative microscale actuators, and research on how to remotely manipulate actuators is also constantly being conducted. Various manipulation methods have been devised including the magnetic, optical, and acoustic control of microscale actuators, demonstrating the great potential for non-contact and non-invasive control. However, research related to the precise control of microscale actuators is still in the early stages, and in-depth research is needed for the efficient control and diversification of a range of applications. In the future, the combination of the fs laser-based fabrication technique for the precise fabrication of microscale actuators/robots and their manipulation can be established as a next-generation processing method by presenting the possibility of applications to various areas.

Dual Regime Spray Deposition Based Laser Direct Writing of Metal Patterns on Polymer Substrates

2020 ◽  
Vol 8 (2) ◽  
Author(s):  
Semih Akin ◽  
Ted Gabor ◽  
Seunghwan Jo ◽  
Hangeun Joe ◽  
Jung-Ting Tsai ◽  
...  
Keyword(s):  
Spray Deposition ◽  
Polymer Surface ◽  
Surface Preparation ◽  
Dip Coating ◽  
Polymer Materials ◽  
Activation Process ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Polymer Substrates ◽  
Metallization Of Polymers

Abstract In recent years, the metallization of polymers has been intensely studied as it takes advantage of both plastics and metals. Laser direct writing (LDW) is one of the most widely used technologies to obtain metal patterns on polymer substrates. In LDW technology, different methods including injection-molding, drop-casting, dip coating, and spin coating are utilized for surface preparation of polymer materials prior to the laser activation process. In this study, an atomization based dual regime spray coating system is introduced as a novel method to prepare the surface of the materials for LDW of metal patterns. Copper micropatterns on the polymer surface were achieved with a minimum feature size of 30 μm, having a strong adhesion and excellent conductivity. The results show that the dual regime spray deposition system can be potentially used to obtain uniform thin film coating with relatively less material consumption on the substrates for surface preparation of laser direct metallization of polymers.

Femtosecond-laser direct writing for spatially localized synthesis of PPV

2017 ◽  
Vol 5 (14) ◽  
pp. 3579-3584 ◽  
Author(s):  
Oriana I. Avila ◽  
Juliana M. P. Almeida ◽  
Franciele R. Henrique ◽  
Ruben D. Fonseca ◽  
Gustavo F. B. Almeida ◽  
...  
Keyword(s):  
Laser Pulses ◽  
Photon Absorption ◽  
Direct Laser Writing ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Thermal Reactions ◽  
Two Photon Absorption ◽  
Two Photon ◽  
Direct Laser ◽  
Fs Laser

Conversion of PTHT into PPV is achieved by direct laser writing. Fs-laser pulses induce photo-thermal reactions due to two-photon absorption, resulting in the microscopic control of PPV polymerization. Such methodology is a promising way towards the fabrication of arbitrary polymeric microcircuits.

UV laser direct writing of 2D/3D structures using photo-curable polydimethylsiloxane (PDMS)

2017 ◽  
Vol 123 (7) ◽  
Author(s):  
Kotaro Obata ◽  
Shayna Slobin ◽  
Adam Schonewille ◽  
Arndt Hohnholz ◽  
Claudia Unger ◽  
...  
Keyword(s):  
Direct Writing ◽  
Uv Laser ◽  
Laser Direct Writing ◽  
3D Structures

scholarly journals Rapid Laser Direct Writing of Plasmonic Components

2017 ◽  
Vol 9 (6) ◽  
pp. 19
Author(s):  
G. Amoako ◽  
W. Zhang ◽  
M. Zhou ◽  
S. S. Sackey ◽  
P. Mensah-Amoah
Keyword(s):  
System Construction ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Scale Level ◽  
New Device ◽  
Two Photon ◽  
Leakage Radiation ◽  
Dielectric Structures ◽  
Plasmon Polaritons

A new device named technology-plasmonics has recently emerged and can be used to manipulate light at the nano-scale level. Here, we report the method of two-photon photopolymerization for rapid laser direct writing of plasmonic components. The characterization of these components is performed by a leakage radiation microscope, which has the same system construction as the two-photon photopolymerization micro-fabrication system except the laser pattern. The dielectric structures covered with gold proved to be very efficient for the excitation of surface plasmon polaritons in this system and can achieve different plasmon fields.

Two-photon nanolithography of positive photoresist thin film with ultrafast laser direct writing

2013 ◽  
Vol 102 (20) ◽  
pp. 201108 ◽  
Author(s):  
Hong-Zhong Cao ◽  
Mei-Ling Zheng ◽  
Xian-Zi Dong ◽  
Feng Jin ◽  
Zhen-Sheng Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Ultrafast Laser ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Positive Photoresist ◽  
Two Photon

Three-dimensional sub-wavelength fabrication by integration of additive and subtractive femtosecond-laser direct writing

2013 ◽  
Vol 1499 ◽  
Author(s):  
Wei Xiong ◽  
Yunshen Zhou ◽  
Xiangnan He ◽  
Yang Gao ◽  
Masoud Mahjouri-Samani ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Three Dimensional ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Nano Fabrication ◽  
Two Photon ◽  
Micro Fluidics ◽  
Wide Range ◽  
Device Structures ◽  
Two Photon Polymerization

ABSTRACTAdditive nanofabrication by two-photon polymerization (TPP) has recently drawn increased attention due to its sub-100 nm resolution and truly three-dimensional (3D) structuring capability. However, besides additive processes, subtractive process is also demanded for many 3D fabrications. Method possessing both additive and subtractive fabrication capabilities was rarely reported. In this study, we developed a complementary 3D micro/nano-fabrication process by integrating both additive two-photon polymerization (TPP) and subtractive multi-photon ablation (MPA) into a single platform of femtosecond-laser direct writing process. Functional device structures were successfully fabricated including: polymer fiber Bragg gratings containing periodic holes of 500-nm diameter and 3D micro-fluidic systems containing arrays of channels of 1-µm diameter. The integration of TPP and MPA processes enhances the nanofabrication efficiency and enables the fabrication of complex 3D micro/nano-structures that are impractical to produce by either TPP or MPA alone, which is promising for a wide range of applications including integrated optics, metamaterials, MEMS, and micro-fluidics.

scholarly journals Laser Direct Writing via Two-Photon Polymerization of 3D Hierarchical Structures with Cells-Antiadhesive Properties

2021 ◽  
Vol 22 (11) ◽  
pp. 5653
Author(s):  
Irina A. Paun ◽  
Bogdan S. Calin ◽  
Cosmin C. Mustaciosu ◽  
Eugenia Tanasa ◽  
Antoniu Moldovan ◽  
...  
Keyword(s):  
Cell Attachment ◽  
Hierarchical Structures ◽  
Contact Angles ◽  
Polymer Surfaces ◽  
Direct Writing ◽  
Laser Direct Writing ◽  
Cellular Behavior ◽  
Two Photon ◽  
Round Shape ◽  
Cellular Attachment

We report the design and fabrication by laser direct writing via two photons polymerization of innovative hierarchical structures with cell-repellency capability. The structures were designed in the shape of “mushrooms”, consisting of an underside (mushroom’s leg) acting as a support structure and a top side (mushroom’s hat) decorated with micro- and nanostructures. A ripple-like pattern was created on top of the mushrooms, over length scales ranging from several µm (microstructured mushroom-like pillars, MMP) to tens of nm (nanostructured mushroom-like pillars, NMP). The MMP and NMP structures were hydrophobic, with contact angles of (127 ± 2)° and (128 ± 4)°, respectively, whereas flat polymer surfaces were hydrophilic, with a contact angle of (43 ± 1)°. The cell attachment on NMP structures was reduced by 55% as compared to the controls, whereas for the MMP, a reduction of only 21% was observed. Moreover, the MMP structures preserved the native spindle-like with phyllopodia cellular shape, whereas the cells from NMP structures showed a round shape and absence of phyllopodia. Overall, the NMP structures were more effective in impeding the cellular attachment and affected the cell shape to a greater extent than the MMP structures. The influence of the wettability on cell adhesion and shape was less important, the cellular behavior being mainly governed by structures’ topography.

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