Submit to Materials Review for Materials Propose a Special Issue

Journal Menu

Journal Browser

► Journal Browser

Materials for Photolithography and 3D Printing

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Benefits of Publishing in a Special Issue
Published Papers

A special issue of Materials (ISSN 1996-1944).

Deadline for manuscript submissions: closed (1 September 2019) | Viewed by 81727

Share This Special Issue

Special Issue Editors

Prof. Dr. Roberta Maria Bongiovanni

E-Mail Website
Guest Editor

Department of Applied Science and Technology-DISAT Politecnico di Torino Corso Duca degli Abruzzi 24, 10129 Torino, Italy
Interests: polymer surface modification; fluoropolymers; cellulosic materials and composites
Special Issues, Collections and Topics in MDPI journals

Dr. Alessandra Vitale

E-Mail Website
Guest Editor

Department of Applied Science and Technology, Politecnico di Torino, 10129 Torino, Italy
Interests: photopolymers; patterning; electrospinning
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Photolithography (PL) is a well-established optical means for transferring patterns onto a substrate. First conceived for producing printed circuits, it is a key process in the semiconductor industry where it is used for creating small structures on a silicon wafer using a photomask, which contains the pattern to be transferred, and a photosensitive material (the photoresist). The photoresist is an organic monomer or polymer, which changes its chemical structure when exposed to light, either becoming soluble or insoluble. Features appear upon selective exposure to light and removal of the soluble material, then the pattern obtained can subsequently be processed (e.g., used as a mask for substrate etching).

As PL can produce extremely small patterns down to tens of nanometers in size, and it provides exact control over the shape and size of the pattern, its applications over the years have extended from electronics to a variety of domains of micro- and nano-fabrication, such as microfluidics, photovoltaics, optics, sensors, and tissue engineering.

In 1986, photolithography went 3D and the term “stereolithography” (SLA) was coined in C. W. Hull’s patent: the technique became a method for making solid objects slice by slice, by successively “printing” thin layers of a light sensitive material one on top of the other. SLA, together with other methodologies associated to photopolymerization processes, is one of the most reliable and versatile techniques of additive manufacturing, often referred as 3D printing. 3D printing, encompassing a wide range of technologies, is regarded as a new ‘turning point’ in industrial production, which will “disrupt business as we know it” (from Forbes, 29 June 2015).

We believe that the growth of 3D printing will also depend on the performance of the materials employed and the development of new materials. Aiming to highlight this concept, this Special Issue will focus on the monomeric and polymeric materials currently used in photolithography, stereolithography, 3D printing, and other additive manufacturing techniques, as well as featuring emerging material-based developments.

We kindly invite you to submit a manuscript(s) for this Special Issue. Full papers, communications, and reviews are all welcome.

Prof. Dr. Roberta Bongiovanni
Dr. Alessandra Vitale
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Materials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

photopolymers
photoresists
photolithography
stereolithography
3D printing
additive manufacturing

Benefits of Publishing in a Special Issue

Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (9 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

12 pages, 2193 KiB

Open AccessFeature PaperArticle

Photopatternable Epoxy-Based Thermosets

by Michael Giebler, Simone Radl, Thomas Ules, Thomas Griesser and Sandra Schlögl

Materials 2019, 12(15), 2350; https://doi.org/10.3390/ma12152350 - 24 Jul 2019

Cited by 7 | Viewed by 3793

Abstract

The present work provides a comparative study on the photopatterning of epoxy-based thermosets as a function of network structure and network mobility. Local switching of solubility properties by light of a defined wavelength is achieved by exploiting versatile o-nitrobenzyl ester (o-NBE) chemistry. o-NBE derivatives with terminal epoxy groups are synthetized and thermally cured with different types of cycloaliphatic anhydrides via nucleophilic ring opening reaction. By varying the structure of the anhydride, glass transition temperature (T_g) and surface hardness are adjusted over a broad range. Once the network has been formed, the photolysis of the o-NBE groups enables a well-defined degradation of the 3D network. Fourier transform infrared (FT-IR) spectroscopy studies demonstrate that cleavage rate and cleavage yield increase with rising mobility of the network, which is either facilitated by inherent network properties (T_g below room temperature) or a simultaneous heating of the thermosets above their T_g. The formation of soluble species is evidenced by sol-gel analysis, revealing that low-T_g networks are prone to secondary photoreactions at higher exposure doses, which lead to a re-crosslinking of the cleaved polymer chains. The change in solubility properties is exploited to inscribe positive tone micropatterns within the thermosets by photolithographic techniques. Contrast curves show that the resist performance of rigid networks is superior to flexible ones, with a contrast of 1.17 and a resolution of 8 µm. Full article

(This article belongs to the Special Issue Materials for Photolithography and 3D Printing)

► Show Figures

Graphical abstract

16 pages, 2348 KiB

Open AccessArticle

3D Printed, PVA–PAA Hydrogel Loaded-Polycaprolactone Scaffold for the Delivery of Hydrophilic In-Situ Formed Sodium Indomethacin

by Mershen Govender, Sunaina Indermun, Pradeep Kumar, Yahya E. Choonara and Viness Pillay

Materials 2018, 11(6), 1006; https://doi.org/10.3390/ma11061006 - 13 Jun 2018

Cited by 14 | Viewed by 5624

Abstract

3D printed polycaprolactone (PCL)-blended scaffolds have been designed, prepared, and evaluated in vitro in this study prior to the incorporation of a polyvinyl alcohol–polyacrylic acid (PVA–PAA) hydrogel for the delivery of in situ-formed sodium indomethacin. The prepared PCL–PVA–PAA scaffold is proposed as a potential structural support system for load-bearing tissue damage where inflammation is prevalent. Uniaxial strain testing of the PCL-blended scaffolds were undertaken to determine the scaffold’s resistance to strain in addition to its thermal, structural, and porosimetric properties. The viscoelastic properties of the incorporated PVA–PAA hydrogel has also been determined, as well as the drug release profile of the PCL–PVA–PAA scaffold. Results of these analyses noted the structural strength, thermal stability, and porosimetric properties of the scaffold, as well as the ability of the PCL–PVA–PAA scaffold to deliver sodium indomethacin in simulated physiological conditions of pH and temperature. The results of this study therefore highlight the successful design, fabrication, and in vitro evaluation of a 3D printed polymeric strain-resistant supportive platform for the delivery of sodium indomethacin. Full article

(This article belongs to the Special Issue Materials for Photolithography and 3D Printing)

► Show Figures

Graphical abstract

5970 KiB

Open AccessArticle

Anisotropy of Photopolymer Parts Made by Digital Light Processing

by Mario Monzón, Zaida Ortega, Alba Hernández, Rubén Paz and Fernando Ortega

Materials 2017, 10(1), 64; https://doi.org/10.3390/ma10010064 - 13 Jan 2017

Cited by 125 | Viewed by 9844

Abstract

Digital light processing (DLP) is an accurate additive manufacturing (AM) technology suitable for producing micro-parts by photopolymerization. As most AM technologies, anisotropy of parts made by DLP is a key issue to deal with, taking into account that several operational factors modify this characteristic. Design for this technology and photopolymers becomes a challenge because the manufacturing process and post-processing strongly influence the mechanical properties of the part. This paper shows experimental work to demonstrate the particular behavior of parts made using DLP. Being different to any other AM technology, rules for design need to be adapted. Influence of build direction and post-curing process on final mechanical properties and anisotropy are reported and justified based on experimental data and theoretical simulation of bi-material parts formed by fully-cured resin and partially-cured resin. Three photopolymers were tested under different working conditions, concluding that post-curing can, in some cases, correct the anisotropy, mainly depending on the nature of photopolymer. Full article

(This article belongs to the Special Issue Materials for Photolithography and 3D Printing)

► Show Figures

Graphical abstract

2642 KiB

Open AccessArticle

Frontal Conversion and Uniformity in 3D Printing by Photopolymerisation

by Alessandra Vitale and João T. Cabral

Materials 2016, 9(9), 760; https://doi.org/10.3390/ma9090760 - 7 Sep 2016

Cited by 86 | Viewed by 9605

Abstract

We investigate the impact of the non-uniform spatio-temporal conversion, intrinsic to photopolymerisation, in the context of light-driven 3D printing of polymers. The polymerisation kinetics of a series of model acrylate and thiol-ene systems, both neat and doped with a light-absorbing dye, is investigated experimentally and analysed according to a descriptive coarse-grained model for photopolymerisation. In particular, we focus on the relative kinetics of polymerisation with those of 3D printing, by comparing the evolution of the position of the conversion profile (z_f) to the sequential displacement of the object stage (∆z). After quantifying the characteristic sigmoidal monomer-to-polymer conversion of the various systems, with a combination of patterning experiments, FT-IR mapping, and modelling, we compute representative regimes for which z_f is smaller, commensurate with, or larger than ∆z. While non-monotonic conversion can be detrimental to 3D printing, for instance in causing differential shrinkage of inhomogeneity in material properties, we identify opportunities for facile fabrication of modulated materials in the z-direction (i.e., along the illuminated axis). Our simple framework and model, based on directly measured parameters, can thus be employed in photopolymerisation-based 3D printing, both in process optimisation and in the precise design of complex, internally stratified materials by coupling the z-stage displacement and frontal polymerisation kinetics. Full article

(This article belongs to the Special Issue Materials for Photolithography and 3D Printing)

► Show Figures

Graphical abstract

2713 KiB

Open AccessArticle

A Facile in Situ and UV Printing Process for Bioinspired Self-Cleaning Surfaces

by Marina A. González Lazo, Ioannis Katrantzis, Sara Dalle Vacche, Feyza Karasu and Yves Leterrier

Materials 2016, 9(9), 738; https://doi.org/10.3390/ma9090738 - 30 Aug 2016

Cited by 18 | Viewed by 6820

Abstract

A facile in situ and UV printing process was demonstrated to create self-cleaning synthetic replica of natural petals and leaves. The process relied on the spontaneous migration of a fluorinated acrylate surfactant (PFUA) within a low-shrinkage acrylated hyperbranched polymer (HBP) and its chemical immobilization at the polymer-air interface. Dilute concentrations of 1 wt. % PFUA saturated the polymer-air interface within 30 min, leading to a ten-fold increase of fluorine concentration at the surface compared with the initial bulk concentration and a water contact angle (WCA) of 108°. A 200 ms flash of UV light was used to chemically crosslink the PFUA at the HBP surface prior to UV printing with a polydimethylsiloxane (PDMS) negative template of red and yellow rose petals and lotus leaves. This flash immobilization hindered the reverse migration of PFUA within the bulk HBP upon contacting the PDMS template, and enabled to produce texturized surfaces with WCA well above 108°. The synthetic red rose petal was hydrophobic (WCA of 125°) and exhibited the adhesive petal effect. It was not superhydrophobic due to insufficient concentration of fluorine at its surface, a result of the very large increase of the surface of the printed texture. The synthetic yellow rose petal was quasi-superhydrophobic (WCA of 143°, roll-off angle of 10°) and its self-cleaning ability was not good also due to lack of fluorine. The synthetic lotus leaf did not accurately replicate the intricate nanotubular crystal structures of the plant. In spite of this, the fluorine concentration at the surface was high enough and the leaf was superhydrophobic (WCA of 151°, roll-off angle below 5°) and also featured self-cleaning properties. Full article

(This article belongs to the Special Issue Materials for Photolithography and 3D Printing)

► Show Figures

Graphical abstract

3686 KiB

Open AccessArticle

A Novel Fabrication Technique for Liquid-Tight Microchannels by Combination of a Paraffin Polymer and a Photo-Curable Silicone Elastomer

by Katsuo Mogi, Kenshiro Sakata, Yuki Hashimoto and Takatoki Yamamoto

Materials 2016, 9(8), 621; https://doi.org/10.3390/ma9080621 - 27 Jul 2016

Cited by 7 | Viewed by 6317

Abstract

The development and growth of microfluidics has been mainly based on various novel fabrication techniques for downsizing and integration of the micro/nano components. Especially, an effective fabrication technique of three-dimensional structures still continues to be strongly required in order to improve device performance, functionality, and device packing density because the conventional lamination-based technique for integrating several two-dimensional components is not enough to satisfy the requirement. Although three-dimensional printers have a high potential for becoming an effective tool to fabricate a three-dimensional microstructure, a leak caused by the roughness of a low-precision structure made by a 3D printer is a critical problem when the microfluidic device is composed of several parts. To build a liquid-tight microchannel on such a low-precision structure, we developed a novel assembly technique in which a paraffin polymer was used as a mold for a microchannel of photo-curable silicone elastomer on a rough surface. The shape and roughness of the molded microchannel was in good agreement with the master pattern. Additionally, the seal performance of the microchannel was demonstrated by an experiment of electrophoresis in the microchannel built on a substrate which has a huge roughness and a joint. Full article

(This article belongs to the Special Issue Materials for Photolithography and 3D Printing)

► Show Figures

Figure 1

3153 KiB

Open AccessFeature PaperArticle

In Situ Thermal Generation of Silver Nanoparticles in 3D Printed Polymeric Structures

by Erika Fantino, Annalisa Chiappone, Flaviana Calignano, Marco Fontana, Fabrizio Pirri and Ignazio Roppolo

Materials 2016, 9(7), 589; https://doi.org/10.3390/ma9070589 - 19 Jul 2016

Cited by 82 | Viewed by 10768

Abstract

Polymer nanocomposites have always attracted the interest of researchers and industry because of their potential combination of properties from both the nanofillers and the hosting matrix. Gathering nanomaterials and 3D printing could offer clear advantages and numerous new opportunities in several application fields. Embedding nanofillers in a polymeric matrix could improve the final material properties but usually the printing process gets more difficult. Considering this drawback, in this paper we propose a method to obtain polymer nanocomposites by in situ generation of nanoparticles after the printing process. 3D structures were fabricated through a Digital Light Processing (DLP) system by disolving metal salts in the starting liquid formulation. The 3D fabrication is followed by a thermal treatment in order to induce in situ generation of metal nanoparticles (NPs) in the polymer matrix. Comprehensive studies were systematically performed on the thermo-mechanical characteristics, morphology and electrical properties of the 3D printed nanocomposites. Full article

(This article belongs to the Special Issue Materials for Photolithography and 3D Printing)

► Show Figures

Graphical abstract

2107 KiB

Open AccessArticle

UV-Assisted 3D Printing of Glass and Carbon Fiber-Reinforced Dual-Cure Polymer Composites

by Marta Invernizzi, Gabriele Natale, Marinella Levi, Stefano Turri and Gianmarco Griffini

Materials 2016, 9(7), 583; https://doi.org/10.3390/ma9070583 - 16 Jul 2016

Cited by 138 | Viewed by 19415

Abstract

Glass (GFR) and carbon fiber-reinforced (CFR) dual-cure polymer composites fabricated by UV-assisted three-dimensional (UV-3D) printing are presented. The resin material combines an acrylic-based photocurable resin with a low temperature (140 °C) thermally-curable resin system based on bisphenol A diglycidyl ether as base component, an aliphatic anhydride (hexahydro-4-methylphthalic anhydride) as hardener and (2,4,6,-tris(dimethylaminomethyl)phenol) as catalyst. A thorough rheological characterization of these formulations allowed us to define their 3D printability window. UV-3D printed macrostructures were successfully demonstrated, giving a clear indication of their potential use in real-life structural applications. Differential scanning calorimetry and dynamic mechanical analysis highlighted the good thermal stability and mechanical properties of the printed parts. In addition, uniaxial tensile tests were used to assess the fiber reinforcing effect on the UV-3D printed objects. Finally, an initial study was conducted on the use of a sizing treatment on carbon fibers to improve the fiber/matrix interfacial adhesion, giving preliminary indications on the potential of this approach to improve the mechanical properties of the 3D printed CFR components. Full article

(This article belongs to the Special Issue Materials for Photolithography and 3D Printing)

► Show Figures

Graphical abstract

4907 KiB

Open AccessArticle

Forming Spacers in Situ by Photolithography to Mechanically Stabilize Electrofluidic-Based Switchable Optical Elements

by Meihong Wang, Yuanyuan Guo, Robert A. Hayes, Danqing Liu, Dirk J. Broer and Guofu Zhou

Materials 2016, 9(4), 250; https://doi.org/10.3390/ma9040250 - 30 Mar 2016

Cited by 10 | Viewed by 6814

Abstract

Electro-Fluidic Displays (EFD) have been demonstrated to be an attractive technology for incorporation into portable display devices. EFDs have excellent optical efficiency and fast switching enabling video content. Ensuring mechanical stability of EFD display cells is a key challenge and essential for developing large area as well as flexible displays. Although the electro-optic performance of an EFD, unlike a liquid crystal display (LCD), is insensitive to cell-gap, extreme changes in cell-gap can result in irreversible collapse of the cell. Here we use photolithography to develop spacers to prevent cell-gap collapse and provide the required mechanical stability for EFD devices. The spacer is formed directly on the cover plates (ITO/glass) after cell assembly with UV light induced phase separation polymerization in the illuminated area. Phase separation behavior between polar aqueous solution and polymer is closely related to the solubility of acrylate monomers. In this work, polyethylene glycol diacrylate (PEGDA) as cross-linker, 2-hydroxyethyl acrylate (HEA) and acrylic acid or acrylamide as co-monomers are investigated for fabricating the spacers. PEGDA was added to the mixtures in order to increase the mechanical strength of the spacer. The spacers showed excellent performance for cell-gap control in EFD devices. Full article

(This article belongs to the Special Issue Materials for Photolithography and 3D Printing)

► Show Figures

Journal Menu

Journal Browser

Materials for Photolithography and 3D Printing

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (9 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI