3-D printing has potential to revolutionize manufacturing of customized low-cost scientific equipment, and numerous self-designed applications have already been realized and demonstrated. However, the applicability of 3-D printed devices to cleanrooms used for semiconductor processing is not as straightforward, as the controlled environment sets strict requirements for the allowed materials and items. This work investigates the opportunity to utilize 3-D printing in cleanrooms by analyzing th...
Abstract Social media is a form of electronic communication (such as websites for social networking and microblogging) through which users create online communities to share information, ideas, personal messages, and other contents (such as videos and audios). It is also a collection of online communications channels dedicated to community-based input, interaction, content-sharing and collaboration; websites dedicated to forums, microblogging, social networking, social bookmarking and social...
Abstract Social media is a form of electronic communication (such as websites for social networking and microblogging) through which users create online communities to share information, ideas, personal messages, and other contents (such as videos and audios). It is also a collection of online communications channels dedicated to community-based input, interaction, content-sharing and collaboration; websites dedicated to forums, microblogging, social networking, social bookmarking and social...
This paper seeks to contribute to recent food security debate. On the basis of field study conducted in three low income areas of Manzini, this study investigated how insufficient food has become a chronic development problem in Africa’s urban area due to rapid urbanization which is eating up the resourceful land and pushing food production further away. Therefore this study was designed to capture the role of migration, urbanization and its implications on food security among the selected ...
Three types of highly-customizable open source probe positioning systems are evaluated: (a) mostly 3-D printed, (b) partially printed using OpenBeam kinematic constraints, and (c) a 3-level stack of low-cost commercial single axis micropositioners and some printed parts. All systems use digital distributed manufacturing to enable bespoke features, which can be fabricated with RepRap-class 3-D printer and easily accessible components. They are all flexible in material choice for custom compone...
The Michigan furniture industry produces >150 tons/day of wood-based waste, which can be upcycled into a wood polymer composite (WPC). This study investigates the viability of using furniture waste as a feedstock for 3-D printer filament to produce furniture components. The process involves: grinding/milling board scraps made of both LDF/MDF/LDF and melamine/particleboard/paper impregnated with phenolic resins; pre-mixing wood-based powder with the biopolymer poly lactic acid (PLA), extruding...
The photovoltaic (PV) industry requires efficient cutting of large single and multi-crystalline (sc- and mc-) silicon (Si) wafers. Historically multi-wire slurry sawing (MWSS) dominated, but the higher productivity of diamond-wire-sawing (DWS) holds promise for decreasing PV costs in the future. While surface texturing of DWS wafers is more complicated than of MWSS wafers, especially in mc-Si wafers, nanotexturing has been shown to overcome this challenge. While the benefit of nanotexturing i...
Although distributed additive manufacturing can provide high returns on investment, the current markup on commercial filament over base polymers limits deployment. These cost barriers can be surmounted by eliminating the entire process of fusing filament by three-dimensional (3-D) printing products directly from polymer granules. Fused granular fabrication (FGF) (or fused particle fabrication (FPF)) is being held back in part by the accessibility of low-cost pelletizers and choppers. An open-...
RepRaps (self Replicating Rapid prototypers), which 3-D print objects using fused filament fabrication (FFF), have evolved rapidly since their open source introduction. These 3-D printers have primarily been limited to desktop sizes of volumes of ~8000 cm 3 , which has limited the attention of the scientific community to investigating deformation of common thermoplastics such as polylactic acid (PLA) used in FFF printing. The only existing physically relevant deformation model was expanded he...
This paper presents a novel design for the top contact of thin film photovoltaic (PV) solar cells. The new top contact is formed by fabricating a 20nm thin honeycomb shaped silver mesh on top of an ultra-thin 13nm of indium tin oxide. The new top contact offers the potential to reduce the series resistance of the cell while increasing the light current via plasmonic resonance. Using the nano-bead lithography technique the honeycomb top contact was fabricated and electrically characterized. Th...
Does a national research-focused organization need a technically competent leader? This study provides preliminary answers to that question using a natural experiment underway at the Department of Energy (DOE): a leader with significant high-level management experience superior to that of his predecessors, but no relevant technical experience was appointed to run the vast scientific research operation. The following hypothesis is proposed: A major risk of allowing technically-unqualified lead...
Titanium dioxide (TiO2) nanostructures (nanorods and nanoparticles) were prepared using a low-cost microwave irradiation method from a polyol medium of glycerol. Titanium glycerolate and TiO2 powders were obtained in the glycerol medium for the first time with four different power densities (240 W, 480 W, 720 W, 960 W) of irradiation using a domestic microwave oven of 2.45 GHz, to understand the impact of power on morphology tuning. The structural and morphological features of the t...
A full mechanical characterisation of three types of 3-D printed lattice cores was performed to evaluate the feasibility of using additive manufacturing (AM) of lightweight polymer-based sandwich panels for structural applications. Effects of the shape of three selected lattice structures on the compression, shear and bending strength has been experimentally investigated. The specimens tested were manufactured with an open source fused filament fabrication-based 3-D printer. These sandwich st...
Anatase TiO2 displaying dual morphologies were synthesized with a simple chemical route via a single step. A strong correlation between the dye sensitized solar cell (DSSC) device performance and the obtained dual morphologies are highlighted using relevant evidences from UV-vis and diffuse reflectance spectroscopy (DRS), Raman analysis, field emission scanning electron microscope, high resolution transmission electron microscope, current-voltage characteristics and impedance analysis. Struct...
In this work, upgraded metallurgical grade silicon (UMG-Si) wafer was used to fabricate mesoporous nanostructures, as an effective antireflection layer for solar photovoltaic cells. The length of the vertical Si nanostructure (SiNS) arrays was altered by varying the etching time period during metal assisted chemical etching (MACE) process, using a silver catalyst. The optical, structural, morphological changes and the antireflection properties of Si nanostructures formed on UMG-Siwafer were a...