Epiphanic Revival: Exploring Metallic Finishes on Batik Fabrics in Ghana

Batik fabric is an integral part of the traditional cloth culture of the Ghanaian traditional setting. However, the batik fabric has marginal usage due to its casual visual appearance. This studio practice seeks to explore the epiphanic revival in the use of metallic finishes on batik substrate to create an enhanced visual appearance with embellished aesthetic sensibilities and diversified use. The researchers adopted the studio-based approach of the qualitative design to manipulate handmade tools, techniques (collagraph) and the batik fabrics through experimentation to produce a glittering mercurial batik fabric which is typically an industrial practice. The studio practice took place at the Textile Design and Technology studio, Takoradi Technical University, Ghana. The traditional batik fabric was manipulated through fabric decoration techniques in accordance with studio-based practices. The Addie model was adopted as a methodological approach in the analysis, design, development, implementation, and evaluation processes of the experimentation processes of the study. Findings revealed that the hand techniques used in the production process for the metallic prints produced interesting accidentals finishes and effects that machine work cannot achieve, producing new discoveries of visual enhancements of traditional batik fabric. Traditional batiks became mercurial with glittery effects. The metallic prints on the fabric also changed its consumption pattern from mere casual fabric to classic and cosmopolitan fabric for varied uses suitable for wearable to non-wearable.

High-efficiency stretchable organic light-emitting diodes based on ultra-flexible printed embedded metal composite electrodes

Stretchable organic light-emitting diodes(OLEDs)are important components for flexible/wearable electronics.However,the efficiency of the existing stretchable OLEDs is still much lower as compared with their rigid counterparts,one of the main reasons being the lack of ideal flexible transparent electrodes.Herein,we propose and develop a printed embedded metal composite electrode(PEMCE)strategy that enables the fabrication of ultra-thin,highly flexible transparent electrodes with robust mechanical properties.With the flexible transparent electrodes serves as the anodes,flexible/stretchable white OLEDs have been successfully constructed,achieving a current efficiency of up to 77.4 cd A^(-1)and a maximum luminance of 34787 cd m^(-2).The current efficiency of the resulting stretchable OLEDs is the highest ever reported for flexible/stretchable white OLEDs,which is about 1.2 times higher than that of the reference rigid devices based on ITO/glass electrodes.The excellent optoelectronic properties of the printed embedded transparent electrodes and the light extraction effect of the Ag-mesh account for the significant increase in current efficiency.Remarkably,the electroluminescence performance still retains~83%of the original luminance even after bending the device 2000 cycles at a radii of~0.5 mm.More importantly,the device can withstand tensile strains of up to~100%,and even mechanical deformation of 90%tensile strain does not result in a significant loss of electroluminescence performance with current efficiency and luminance maintained at over 85%.The results confirm that the PEMCE strategy is effective for constructing ultra-flexible transparent electrodes,showing great promise for use in a variety of flexible/stretchable electronics.

Frontiers of 3D Printing/Additive Manufacturing: from Human Organs to Aircraft Fabrication

It has been more than three decades since stereolithography began to emerge in various forms of additive manufacturing and 3D printing. Today these technologies are proliferating worldwide in various forms of advanced manufacturing. The largest segment of the 3D printing market today involves various polymer component fabrications, particularly complex structures not attainable by other manufacturing methods.Conventional printer head systems have also been adapted to selectively print various speciated human cells and special molecules in attempts to construct human organs, beginning with skin and various tissue patches. These efforts are discussed along with metal and alloy fabrication of a variety of implant and bone replacement components by creating powder layers, which are selectively melted into complex forms（such as foams and other open-cellular structures） using laser and electron beams directed by CAD software. Efforts to create a ＂living implant＂ by bone ingrowth and eventual vascularization within these implants will be discussed briefly. Novel printer heads for direct metal droplet deposition as in other 3D printing systems are briefly described since these concepts will allow for the eventual fabrication of very large and complex products, including automotive and aerospace structures and components.

Recent advances in inkjet printing synthesis of functional metal oxides

lnkjet printing （IJP） synthesis has emerged as a useful technique for the fabrication of functional metal oxides in the fields of nanotechnology and materials science. In this paper, we will review the fundamental state-of-the-art principles of the special ink formulations used for IJP synthesis of functional metal oxides and the applications of these oxides.

Printable inorganic nanomaterials for flexible transparent electrodes:from synthesis to application

Printed and flexible electronics are definitely promising cutting-edge electronic technologies of the future. They offer a wide-variety of applications such as flexible circuits, flexible displays, flexible solar cells, skinlike pressure sensors, and radio frequency identification tags in our daily life. As the most-fundamental component of electronics, electrodes are made of conductive materials that play a key role in flexible and printed electronic devices. In this review, various inorganic conductive materials and strategies for obtaining highly conductive and uniform electrodes are demonstrated. Applications of printed electrodes fabricated via these strategies are also described. Nevertheless, there are a number of challenges yet to overcome to optimize the processing and performance of printed electrodes.

Interfacial engineering of printable bottom back metal electrodes for full-solution processed flexible organic solar cells

Printing of metal bottom back electrodes of flexible organic solar cells（FOSCs） at low temperature is of great significance to realize the full-solution fabrication technology. However, this has been difficult to achieve because often the interfacial properties of those printed electrodes, including conductivity, roughness, work function,optical and mechanical flexibility, cannot meet the device requirement at the same time. In this work, we fabricate printed Ag and Cu bottom back cathodes by a low-temperature solution technique named polymer-assisted metal deposition（PAMD） on flexible PET substrates. Branched polyethylenimine（PEI） and ZnO thin films are used as the interface modification layers（IMLs） of these cathodes. Detailed experimental studies on the electrical, mechanical, and morphological properties, and simulation study on the optical properties of these IMLs are carried out to understand and optimize the interface of printed cathodes. We demonstrate that the highest power conversion efficiency over 3.0% can be achieved from a full-solution processed OFSC with the device structure being PAMDAg/PEI/P3 HT：PC61BM/PH1000. This device also acquires remarkable stability upon repeating bending tests.

Energy Absorption Characteristics of a Novel Asymmetric and Rotatable Re-entrant Honeycomb Structure

Based on the symmetric re-entrant honeycomb(S-RH)structure with negative Poisson’s ratios,a novel asymmetric and rotatable re-entrant honeycomb(AR-RH)structure was proposed.Both the S-RH structure and AR-RH structure were produced by the 3D printing technology.Through experimental test and finite element simulation,the deformation mechanism and energy absorption characteristics of the AR-RH structure and the S-RH structure with negative Poisson’s ratios at different impact velocities were compared.The experimental test and finite element simulation results show that the novel AR-RH structure with negative Poisson’s ratios has stronger energy absorption capacity than the S-RH structure,and it has been verified that the rotatability of AR-RH can indeed absorb energy.Furthermore,the degree of asymmetry of the AR-RH structure was discussed.

Particle Swarm Optimization of Printing Parameters for Open-source TIG-based Metal 3D Printing

Proprietary metal 3D printing is still relegated to relatively expensive systems that have been constructed over years of expensive trial-and-error to obtain optimum 3D printing settings.Low-cost open-source metal 3D printers can potentially democratize metal additive manufacturing;however,significant resources are required to redevelop optimal printing parameters for each metal on new machines.In this study,the particle swam optimization(PSO)experimenter,a free and open-source software package,is utilized to obtain the optimal printing parameters for a tungsten inert gas-based metal open source 3D printer.The software is a graphical user interface implementation of the PSO method and is designed specifically for hardware-in-loop testing.It uses the input of experimental variables and their respective ranges,and then proposes iterations for experiments.A custom fitness function is defined to characterize the experimental results and provide feedback to the algorithm for low-cost metal additive manufacturing.Four separate trials are performed to determine the optimal parameters for 3D printing.First,an experiment is designed to deposit and optimize the parameters for a single line.Second,the parameters for a single-layer plane is optimized experimentally.Third,the optimal printing parameters for a cube is determined experimentally.Fourth,the line optimization experiment is revised and reconducted using different shield gas parameters.The results and limitations are presented and discussed in the context of expanding wire arc additive manufacturing to more systems and material classes for distributed digital manufacturing.