Design of a Solar Panel Deployment and Tracking System for Pocketqube Pico-Satellite

Modularized small satellites will have even greater potential with better energy supply. In this paper, a PocketQube solar panel deployment and tracking system will be presented. The system is designed for a 3P PocketQubes. During the designing phase, trade-off analysis is done to meet the balance of weight, dimension and efficiency. Reliability, manufacturability, and cost are also considered from the beginning, as commercial production and launch are expected. The CAD design, dynamics analysis, motion simulation, and rendering for the project are undertaken by Solidworks, whereas Abaqus CAE is utilized for the finite element analysis of the vibration test of the panels. In the gimbal subsystem, we use two micro stepper motor to drive the panels via a two-axis gearbox, enabling the panels to track the sun omnidirectionally. In the panel subsystem, two types of customized spring hinges are designed. Robust and verified parts, such as burner resistors, are chose for the control and deployment system. After the continuous optimization process throughout the design phase, by comparing different manufacturing processes technologies, materials, and design details, the full scale prototypes of the gimbal subsystem were built and tested. In the end, the most feasible solution, as well as the suggestions for the development, were put forward

Shallots skin peeler machine

Shallots have been a popular food for many centuries. Today, they are valued for their flavor, aroma and taste, being prepared domestically or forming raw materials for a variety of food processors. They are probably the most universally used vegetables in most countries. Shallots skin peeling is an essential step in producing many of the shallot products

A Novel Projection Based Electro-Stereolithography (PES) Process for Composite Printing

Most current additive manufacturing processes can only process one material in one build. Few of them are able to fabricate multiple materials and composites, with limited choices of materials. In this research, we propose a novel Projection based Electro-Stereolithography (PES) process, which is able to fabricate composites with high resolution and fast speed, and a big range of material choices. The proposed novel additive manufacturing process integrates projection-based stereolithography and electrophotography approaches by using a photoconductive film and digital micro-mirror device (DMD). In PES, a photoconductive film is used to collect charged particles in the regions illuminated by light. More specifically, a laser beam is scanning on the film to create a latent image on the film and then a layer of charged particles is attracted to the illuminated area. A liquid bridge system and a stamping system have been developed to transfer particles from the film to liquid resin precisely. Furthermore, a digital mask is used to pattern the light irradiation of the DMD chip to selectively cure the photopolymer liquid resin and particles of that layer. By transferring particles with designed patterns to the resin in a projection based stereolithography system, we will be able to fabricate composites with various materials at microscopic resolutions very quickly. Challenges in this novel manufacturing process, including transferring of particles and curing control, have been discussed and addressed. The corresponding key parameters of the particles collecting, dropping and curing in the PES system have been identified. A proof-of-concept PES testbed has been developed and a couple of tests have been performed to validate the feasibility of the proposed additive manufacturing approach.Mechanical Engineerin

Proof-of-concept investigation of Active Velcro for smart attachment mechanisms

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76230/1/AIAA-2001-1503-863.pd

Development of Nanocomposite Powders for the SLS Process to Enhance Mechanical Properties

In an effort to fabricate prototypes with improved mechanical properties in the dual laser sintering process, functionalized graphite nanoplatelets were added to the PA-12 powder to produce a nanocomposite powder. The PA-12 powder was chosen as the matrix polymer because it has features conducive to laser sintering such as relatively low melting temperature and high mechanical properties. The GNPs were oxidized through a nitric acid treatment to improve the interfacial bonding. The resulting nanocomposite powder was layered and sintered by laser without any sign of agglomeration. Although the result is preliminary, it nevertheless shows the suitability of the nanocomposite powder for the laser sintering process.Mechanical Engineerin

Rapid prototyping and time compression

Rapid Prototyping - manufacture by layering processes: Stereolithography Selective Layer Sintering (SLS) Laminated Object Manufacture (LOM) Solid Ground Curing Small batch programmable rapid manufacture with lasers Micro-Engineering – Prototyping and Manufacture Additive - fabrication Subtractive – machinin

Three-Dimensional (3D) Printed Microneedles for Microencapsulated Cell Extrusion

Cell-hydrogel based therapies offer great promise for wound healing. The specific aim of this study was to assess the viability of human hepatocellular carcinoma (HepG2) cells immobilized in atomized alginate capsules (3.5% (w/v) alginate, d = 225 µm ± 24.5 µm) post-extrusion through a three-dimensional (3D) printed methacrylate-based custom hollow microneedle assembly (circular array of 13 conical frusta) fabricated using stereolithography. With a jetting reliability of 80%, the solvent-sterilized device with a root mean square roughness of 158 nm at the extrusion nozzle tip (d = 325 μm) was operated at a flowrate of 12 mL/min. There was no significant difference between the viability of the sheared and control samples for extrusion times of 2 h (p = 0.14, α = 0.05) and 24 h (p = 0.5, α = 0.05) post-atomization. Factoring the increase in extrusion yield from 21.2% to 56.4% attributed to hydrogel bioerosion quantifiable by a loss in resilience from 5470 (J/m3) to 3250 (J/m3), there was no significant difference in percentage relative payload (p = 0.2628, α = 0.05) when extrusion occurred 24 h (12.2 ± 4.9%) when compared to 2 h (9.9 ± 2.8%) post-atomization. Results from this paper highlight the feasibility of encapsulated cell extrusion, specifically protection from shear, through a hollow microneedle assembly reported for the first time in literature

Micro-vascular shape-memory polymer actuators with complex geometries obtaines by laser stereolithography

In our work we present the complete development process of geometrically complex microvascular shape-memory polymer actuators. The complex geometries and three-dimensional networks are designed by means of computer aided design resources. Manufacture is accomplished, in a single step, by means of laser stereolithography, directly from the computeraided design files with the three dimensional geometries of the different actuators under development. To our knowledge, laser stereolithography is applied here for the first time to the development of shape memory polymer devices with complex geometries and inner microvasculatures for their activation using a thermal fluid. Final testing of the developed actuators helps to validate the approach and to put forward some present challenges

Changeable Context of the New Technology Artefact and the Changeable Research Outcomes

Computer Aided Drawing (vector based) and painting (raster based) packages, allow the mock-up of designs in virtual space. Whilst this is beneficial for visualising the end product, both methods of drawing have been applied to new and existing machining technologies so that some aspect of the product is derived from a computer file. Today, the applied artist now has an abundance of CAD/CAM (Computer Aided Drawing / Computer Aided Manufacturing) technologies awaiting them. So much so, that in the past fifteen years, many makers have embarked upon practice-led research to find out what a particular technology can do with regard to their design interests. Within such research, the object is the manifestation of what has been discovered through the research activity. This paper considers the relationship between the content of the research object and the context for the object’s reception. This is examined with regard to the author’s research with new technologies for the applied arts. Examples will highlight how the characteristics of artefacts that arise from the research can help determine who the audience for the work is, and how the technology might be used by different kinds of craft practitioners. References will also be made to the work of other designer-makers working with and researching similar technologies. Evidence from practical examples will also be supported by a more theoretical discussion. The implications of supplying, or not supplying, background information for an audience within a variety of settings on the perceived content/context of the object, and the communication of the research, will also be discussed. It is concluded that when developing new processes, keeping the work open to a number of audiences can maximise the outcomes and increase the chances of the process being integrated within practice. The discussion also highlights a trend of positioning the consumer/viewer at the forefront of the research, and a need to evaluate their experiences