20 research outputs found

    Measurement and Process Control in Precision Hot Embossing

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    Microfluidic technologies hold a great deal of promise in advancing the medical field, but transitioning them from research to commercial production has proven problematic. We propose precision hot embossing as a process to produce high volumes of devices with low capital cost and a high degree of flexibility. Hot embossing has not been widely applied to precision forming of hard polymers at viable production rates. To this end we have developed experimental equipment capable of maintaining the necessary precision in forming parameters while minimizing cycle time. In addition, since equipment precision alone does not guarantee consistent product quality, our work also focuses on real-time sensing and diagnosis of the process. This paper covers both the basic details for a novel embossing machine, and the utilization of the force and displacement data acquired during the embossing cycle to diagnose the state of the material and process. The precision necessary in both the forming machine and the instrumentation will be covered in detail. It will be shown that variation in the material properties (e.g. thickness, glass transition temperature) as well as the degree of bulk deformation of the substrate can be detected from these measurements. If these data are correlated with subsequent downstream functional tests, a total measure of quality may be determined and used to apply closed-loop cycle-to-cycle control to the entire process. By incorporating automation and specialized precision equipment into a tabletop “microfactory” setting, we aim to demonstrate a high degree of process control and disturbance rejection for the process of hot embossing as applied at the micron scale.Singapore-MIT Alliance. Manufacturing Systems and Technology Programm

    Agricultural index insurance for development

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    Index insurance is often promoted as a solution to many of the barriers that are thought to limit the supply of formal insurance coverage to smallholder farmers and livestock owners in developing countries. This manuscript summarizes the state of index insurance, paying special attention to the key challenges facing index insurance if it is to become a more effective tool for development. We then offer recommendations to tackle those challenges by strategically investing in a set of public goods and services geared towards addressing key informational gaps and improving the quality of index insurance products around the world
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