Special Issue "Science and Technology of Flexible Films and Devices"

A special issue of Coatings (ISSN 2079-6412). This special issue belongs to the section "Thin Films".

Deadline for manuscript submissions: 31 May 2022.

Special Issue Editor

Dr. Xinge Yu
E-Mail Website
Guest Editor
Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China
Interests: flexible materials and electronics; bio-integrated electronics, biomedical engineering

Special Issue Information

Dear Colleagues,

The recent development of materials and devices in flexible electronics has attracted great attention and provided many opportunities for wearable electronics, human–machine interfaces, Internet of things, and many others. One of the keys to the success of flexible electronics is the development of functional flexible thin films, since flexible electronics technology is highly relevant to thin-film technology. The science and technology of flexible thin-films and devices, associated with the development of novel functional thin films (organic and inorganic semiconducting, conducting, and insulating materials), the exploitation of advanced film deposition methods (chemical/physical vapor deposition, spin-casting, printing, etc.), mechanics design of flexible devices (computational simulation and experiments), and the fabrication of thin-film devices (micro-FAB, assembly, integration, etc.) are extremely important for both academia and industry.

This Special Issue will serve as a forum for papers in the following concepts, but not limited to these:

  • Materials for flexible thin films and devices.
  • Novel deposition and processing techniques for flexible thin films and flexible devices.
  • Mechanics designs and computational simulations for flexible thin films and flexible electronics.
  • Applications of flexible thin films and flexible devices.
  • Physics and chemistry of thin films and thin-film devices.
  • Novel thin-film devices showing potential for flexible electronics.

Assist. Prof. Xinge Yu
Guest Editor

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 papers will be 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. Coatings is an international peer-reviewed open access monthly 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 1800 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

  • thin-film devices
  • flexible electronics
  • thin-film mechanics
  • advanced coating techniques

Published Papers (5 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

Article
A New Strong Form Technique for Thermo-Electro-Mechanical Behaviors of Piezoelectric Solids
Coatings 2021, 11(6), 687; https://doi.org/10.3390/coatings11060687 - 08 Jun 2021
Viewed by 608
Abstract
Piezoelectric materials are widely fabricated and investigated for potential applications in microelectromechanical systems as direct converters between mechanical and electrical signals, where some show pyroelectric features involving thermo-electro-mechanical interactions. This study aimed to introduce a novel numerical technique to predict the thermo-electro-mechanical behaviors [...] Read more.
Piezoelectric materials are widely fabricated and investigated for potential applications in microelectromechanical systems as direct converters between mechanical and electrical signals, where some show pyroelectric features involving thermo-electro-mechanical interactions. This study aimed to introduce a novel numerical technique to predict the thermo-electro-mechanical behaviors of piezoelectric structures, based on a strong-form numerical framework called the element differential method. In this method, the shape functions of the isoparametric element and their first two derivatives were derived analytically by interpolating the temperature, displacement, and electric potentials. Then, a point collocation method based on node positions in the elements was proposed to generate the final system of equations without any domain integrations. Thus, the coupled behaviors of thermal piezoelectric structures, including the pyroelectric features, can be simulated by the strong-form formulation of the governing equations. Several numerical examples, including the piezoelectric composites structures, are presented, and the coupled thermo-electro-mechanical responses have been analyzed to validate the proposed method. Full article
(This article belongs to the Special Issue Science and Technology of Flexible Films and Devices)
Show Figures

Figure 1

Article
Formation of Tribofilm in the Friction of Fluorinated Diamond-Like Carbon (FDLC) Film against Ti6Al4V in Bovine Serum Albumin (BSA) Solution
Coatings 2020, 10(9), 903; https://doi.org/10.3390/coatings10090903 - 20 Sep 2020
Viewed by 730
Abstract
A route to reducing the wear of the metal counterpart in the friction of meatal against diamond-like carbon (DLC) is to form a lubricating tribofilm on the metal counterface. However, in liquid lubricating conditions, the formation of tribofilm can be influenced by both [...] Read more.
A route to reducing the wear of the metal counterpart in the friction of meatal against diamond-like carbon (DLC) is to form a lubricating tribofilm on the metal counterface. However, in liquid lubricating conditions, the formation of tribofilm can be influenced by both the lubricating medium and the counterpart material. Here we report the effect of lubricating biomolecule and doping fluorine element on the formation of tribofilm in fluorinated DLC (FDLC)-Ti6Al4V friction system. A group of ball-on-disc frictional experiments with different sliding speeds and normal loads were performed in phosphate buffer solution (PBS) and bovine serum albumin (BSA) solution. The results showed the formation of tribofilm was inhibited by the absorption of biomolecules on the frictional surface, thus improving the friction coefficient and wear of Ti6Al4V counterpart. Doping fluorine into DLC film also can restrain the formation of tribofilm on Ti6Al4V counterface. As a result, tribofilm is difficult to form when Ti6Al4V counterface slides against FDLC in BSA solution. Fluorinated DLC film should be considered carefully for the anti-wear use in body fluid containing biomolecules because it might cause severe wear of the counterpart material. Full article
(This article belongs to the Special Issue Science and Technology of Flexible Films and Devices)
Show Figures

Figure 1

Article
Skin-Like Strain Sensors Enabled by Elastomer Composites for Human–Machine Interfaces
Coatings 2020, 10(8), 711; https://doi.org/10.3390/coatings10080711 - 23 Jul 2020
Cited by 3 | Viewed by 1048
Abstract
Flexible electronics exhibit tremendous potential applications in biosensing and human–machine interfaces for their outstanding mechanical performance and excellent electrical characteristics. In this work, we introduce a soft, skin-integrated strain sensor enabled by a ternary elastomer composite of graphene/carbon nanotube (CNT)/Ecoflex, providing a low-cost [...] Read more.
Flexible electronics exhibit tremendous potential applications in biosensing and human–machine interfaces for their outstanding mechanical performance and excellent electrical characteristics. In this work, we introduce a soft, skin-integrated strain sensor enabled by a ternary elastomer composite of graphene/carbon nanotube (CNT)/Ecoflex, providing a low-cost skin-like platform for conversion of mechanical motion to electricity and sensing of human activities. The device exhibits high sensitivity (the absolute value of the resistance change rate under a testing strain level, 26) and good mechanical stability (surviving ~hundreds of cycles of repeated stretching). Due to the advanced mechanical design of the metallic electrode, the strain sensor shows excellent mechanical tolerance to pressing, bending, twisting, and stretching. The flexible sensor can be directly mounted onto human skin for detecting mechanical motion, exhibiting its great potential in wearable electronics and human–machine interfaces. Full article
(This article belongs to the Special Issue Science and Technology of Flexible Films and Devices)
Show Figures

Figure 1

Article
Effect of Zirconium Doping on Electrical Properties of Aluminum Oxide Dielectric Layer by Spin Coating Method with Low Temperature Preparation
Coatings 2020, 10(7), 620; https://doi.org/10.3390/coatings10070620 - 29 Jun 2020
Cited by 2 | Viewed by 1008 | Correction
Abstract
In recent years, significant efforts have been devoted to the research and development of spin-coated Al2O3 thin films, due to their large band gaps, high breakdown voltage and stability at high annealing temperature. However, as the alumina precursor has a [...] Read more.
In recent years, significant efforts have been devoted to the research and development of spin-coated Al2O3 thin films, due to their large band gaps, high breakdown voltage and stability at high annealing temperature. However, as the alumina precursor has a large surface energy, substrates need to be treated by plasma before spin coating. Therefore, to avoid the expensive and process-complicated plasma treatment, we incorporated zirconium nitrate into the aluminum nitrate solution to decrease the surface energy of the precursor which improve the spreadability. Then, the electrical performances and the surface morphologies of the films were measured. For comparison, the pure Al2O3 films with plasma treatments were also prepared. As a result, after low temperature annealing (200 °C), the relative dielectric constant of Zr–AlOx spin-coated thin-film MIM (Metal-Insulator-Metal) devices can reach 12 and the leakage current density is not higher than 7.78 × 10−8 A/cm2 @ 1 MV/cm when the concentration of zirconium nitrate is 0.05 mol/L. The Aluminum oxide film prepared by zirconium doping has higher stability and better electrical properties than the pure films with plasma treatments and high performance can be attained under low-temperature annealing, which shows its potential application in printing and flexible electronic devices. Full article
(This article belongs to the Special Issue Science and Technology of Flexible Films and Devices)
Show Figures

Figure 1

Review

Jump to: Research

Review
Implantable Thin Film Devices as Brain-Computer Interfaces: Recent Advances in Design and Fabrication Approaches
Coatings 2021, 11(2), 204; https://doi.org/10.3390/coatings11020204 - 10 Feb 2021
Viewed by 914
Abstract
Remarkable progress has been made in the high resolution, biocompatibility, durability and stretchability for the implantable brain-computer interface (BCI) in the last decades. Due to the inevitable damage of brain tissue caused by traditional rigid devices, the thin film devices are developing rapidly [...] Read more.
Remarkable progress has been made in the high resolution, biocompatibility, durability and stretchability for the implantable brain-computer interface (BCI) in the last decades. Due to the inevitable damage of brain tissue caused by traditional rigid devices, the thin film devices are developing rapidly and attracting considerable attention, with continuous progress in flexible materials and non-silicon micro/nano fabrication methods. Therefore, it is necessary to systematically summarize the recent development of implantable thin film devices for acquiring brain information. This brief review subdivides the flexible thin film devices into the following four categories: planar, open-mesh, probe, and micro-wire layouts. In addition, an overview of the fabrication approaches is also presented. Traditional lithography and state-of-the-art processing methods are discussed for the key issue of high-resolution. Special substrates and interconnects are also highlighted with varied materials and fabrication routines. In conclusion, a discussion of the remaining obstacles and directions for future research is provided. Full article
(This article belongs to the Special Issue Science and Technology of Flexible Films and Devices)
Show Figures

Figure 1

Back to TopTop