Rapid Prototyping (RP) technologies provide the ability to fabricate initial prototypes from various model materials. Stratasys Fused Deposition Modeling (FDM) is a typical RP process that can fabricate prototypes out of ABS plastic. To predict the mechanical behavior of FDM parts, it is critical to understand the material properties of the raw FDM process material, and the effect that FDM build parameters have on anisotropic material properties. This paper characterizes the properties of ABS parts fabricated by the FDM 1650. Using a Design of Experiment (DOE) approach, the process parameters of FDM, such as raster orientation, air gap, bead width, color, and model temperature were examined. Tensile strengths and compressive strengths of directionally fabricated specimens were measured and compared with injection molded FDM ABS P400 material. For the FDM parts made with a 0.003 inch overlap between roads, the typical tensile strength ranged between 65 and 72 percent of the strength of injection molded ABS P400. The compressive strength ranged from 80 to 90 percent of the injection molded FDM ABS. Several build rules for designing FDM parts were formulated based on experimental results.

This paper presents a design methodology for the thermal design and packaging of hybrid electronic-mechanical products. In this work, tight integration between ECAD and MCAD was achieved through the use of a web-based tool used in managing the concurrent designs, called the Domain Unified CAD Environment (DUCADE). This work also reduced the amount of time required for thermal simulation by using a web-based Design of Experiment Testbed (DOET) to systematically determine effects of varying system parameters before full-scale computational fluid dynamics (CFD) thermal modeling was performed. The design process began by proper selection of material, manufacturing process and cooling methods, based on electrical and integrated circuit design. DUCADE was then set up to monitor couplings between the various domains. This was followed by computer-aided-design and computer-aided-engineering of the mechanical package. In computer-aided-engineering, DOET was first used to determine variables that had significant effect on the thermal system response. Detailed CFD thermal simulations were then carried out in FLOTHERM only focusing on variables that the DOET determined to have strong effect. Rapid prototypes were fabricated to refine the design before final production. Each step of the cycle was tested and demonstrated through a case study on the design of the Berkeley Emulation Engine (BEE) which involved multi-disciplinary electrical, mechanical, and thermal design.

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This paper describes experimental results for transmission quality based on antenna direction, packaging materials, and interactions with the local environment. Many mobile devices depend heavily on wireless communications for their operation, making antenna efficiency very important for their successful operation. The Personal Server (PS) research platform enables the user to carry with them their palm-size personal computer anywhere they go. By simply approaching another computer, a kiosk, or other computing interface, all of the user’s data is accessible by wireless connection and transferred to the receiving device. The prototype acts like a mobile server that the consumer can take with and depending on the situation can interact with through any available computing device such as laptops, PCs, tablets, etc. Since the PS uses RF transmission to send files and images to the interfacing computers, maintaining reliable and robust signal strength is important for the device. An experimental approach was used to better understand the factors which may degrade or augment signal strength. The approach taken in this investigation quantifies the effects of human and electronic-mechanical factors on the transmission strength of the PS and help guide decisions on design changes that would favor an improved quality of signal. The investigation looked at two specific areas that could potentially influence signal performance: i) human interaction and usage ii) electronic-mechanical design factors. The first part of the investigation looked at how the device performed in the presence of a human body, specifically the way it was positioned with respect to the user as well as the position of the human body with respect to the receiving antenna. In addition, the signal strength was observed when the PS was in the presence of other objects commonly carried along the human body. The remaining part of the experiment concerned itself with the given design of the device, specifically the PCB components and plastic casing. Factors from both the electronic and mechanical domains, such as battery placement, paint presence on housing, and geometry of casing, were varied simultaneously using a Design of Experiment (DOE) approach.