This paper outlines the evolution of additive manufacturing technology, culminating in 3D printing, and presents a vision of how this evolution is affecting existing global value chains in production. In particular, we bring up questions about how this new technology can affect the geographic span and density of global value chains. Potentially, wider adoption of this technology has the potential to partially reverse the trend towards global specialization of production systems into elements ...
The relationship between microstructure and properties is not widely assessed in parts produced by additive manufacturing, particularly for aluminum. These relationships can be used by engineers to develop new materials, additive processes, and additively manufactured parts for a variety of applications. Thus, the tensile, compressive, and microstructural properties of common aluminum weld filler alloys (ER1100, ER4043, ER4943, ER4047, and ER5356) were evaluated following gas metal arc weld (...
A number of risks could cause widespread electrical failure, including a series of high-altitude electromagnetic pulses (HEMPs) caused by nuclear weapons, an extreme solar storm, and a coordinated cyber attack. Since modern industry depends on electricity, it is likely there would be a collapse of the functioning of industry and machines in these scenarios. As our current high agricultural productivity depends on industry (e.g. for fertilizers) it has been assumed that there would be mass sta...
Nanosphere lithography (NSL) provides an opportunity for a low-cost and scalable method to optically engineer solar photovoltaic (PV) cells. For PV application, NSL is widely used in rear contact scenarios to excite SPP and/or high order diffractions, however, the top contact scenarios using NSL are rare. In this paper a systematic simulation study is conducted to determine the capability of achieving efficiency enhancement in hydrogenated amorphous silicon (a-Si:H) solar cells using NSL as a...
This study reports on a novel synthesis of pure zinc oxide and both Cu and Ag doped ZnO nanoplates using a simple and lowcost hydrothermal method. The structural and optical properties of the nanoplates were quantified and the materials were tested for antibacterial activity. Xray diffraction revealed the formation of the wurtzite phase of ZnO and scanning and transmission electron microscopy showed the formation of randomly oriented ZnO nanoplates, having thickness less than 80 nm and di...
In addition to their low cost and weight, polymer heat exchangers offer good anticorrosion and antifouling properties. In this work, a cost effective air-water polymer heat exchanger made of thin polymer sheets using layer-by-layer line welding with a laser through an additive manufacturing process was fabricated and experimentally tested. The flow channels were made of 150 μm-thick high density polyethylene sheets, which were 15.5 cm wide and 29 cm long. The experimental results show that t...
Alloy development can simplify low-cost gas metal arc weld (GMAW)-based 3-D printing by making it easier to print quality parts with minimal metallurgical or welding experience. Previous work found good properties in aluminum alloys, particularly in the aluminum-silicon 4943 (Al-5.5%Si-0.4%Mg) and 4047 (Al-11.6%Si) alloys. These alloys were easy to print, but could benefit from alloying to increase ductility and to minimize or redistribute porosity. The purpose of this study was to modify 494...
3D printing functional parts with known mechanical properties is challenging using variable open source 3D printers. This study investigates the mechanical properties of 3D printed parts using a commercial open-source 3D printer for a wide range of materials. The samples are tested for tensile strength following ASTM D638. The results are presented and conclusions are drawn about the mechanical properties of various fused filament fabrication materials. The study demonstrates that the tensile...
Solar photovoltaic (PV) systems have the greatest potential to meet the scale of sustainable energy demands, yet large surface areas beyond rooftop areas are required. One source of additional surface area that avoids conflict with food production while scaling with population density is noise barriers, which provide dual use of land area both as noise abatement and energy generation. This paper provides a method to quantify the potential of mass scale deployment of photovoltaic noise barrier...
Solar photovoltaic (PV) technology can provide sustainable power for the growing global population in cities, but it demands considerable land area. This is a challenge for densely populated cities. However, the stranded assets of non-productive parking lots areas can be converted to solar farms with PV canopies, enabling sustainable electricity generation while preserving their function to park automobiles. This study provides a method for determining the technical and economic potential for...
The antibacterial effect of zinc oxide (ZnO#1) as prepared and annealed (ZnO#2) at 400 o C, Cu doped ZnO (CuZnO), and Ag doped ZnO (AgZnO) nanoplates on Staphylococcus epidermidis was investigated for the inhibition and inactivation of cell growth. The results shows that pure ZnO and doped ZnO samples exhibited antibacterial activity against S. epidermidis as compared to tryptic soy broth (TSB). Also it is observed that S. epidermidis was extremely sensitive to treatment with ZnO nanoplates a...
This study analyzes a low-cost reliable real-time optimal monitoring platform for fused filament fabrication-based open source 3-D printing. An algorithm for reconstructing 3-D images from overlapping 2-D intensity measurements with relaxed camera positioning requirements is compared with a single camera solution for single side 3-D printing monitoring. The algorithms are tested for different 3-D object geometry and filament colors. The results showed that both of the algorithms with a single...
Recent advances in the use of plasmonic metamaterials to improve absorption of light in thin-film solar photovoltaic devices has created a demand for a scalable method of patterning large areas with metal nanostructures deposited in an ordered array. This article describes two methods of fabricating ordered 2D nanosphere colloidal films: spin coating and interface coating. The two methods are compared and parameter optimization discussed. The study reveals that: For smaller nanosphere sizes, ...
Thesize effect of nanoscale silicon in both amorphous and porous silicon was investigated with microRaman spectroscopy. Silicon nanostructers in amorphous silicon were deposited on quartz substrates by plasma enhanced chemical vapor deposition (PECVD) with deposition powers of 15, 30 and 50W. MicroRaman spectra of the nanostructured silicon show the T 2g Raman active mode shifting from the 521 cm 1 crystalline Si Raman line to 494, 499 and 504 cm 1 as deposition power increased. Large...
The agglomeration/dewetting process of thin silver films provides a scalable method of obtaining self-assembled nanoparticles (SANPs) for plasmonics based thin-film solar photovoltaic (PV) devices. Here, we show the effect of annealing ambiance on silver SANP average size, particle/cluster finite shape, substrate area coverage/particle distribution and how these physical parameters influence optical properties and surface-enhanced Raman scattering (SERS) responses of SANPs. Statistical analys...