Metal microstructures for shock protection of MEMS

With MEMS (Micro-electro-mechanical systems) becoming increasingly commonplace in many different industries, the need for more robust microstructures that can withstand high-shock environments is growing in importance. Literature currently available is yet to reveal a MEMS shock-absorber which meets our set of requirements, namely that it is suitable for both space and terrestrial applications, is easily incorporated into current MEMS fabrication methods and can absorb significant amounts of energy without needing a power source or without adversely affecting the performance of the device. This thesis presents a novel solution for the shock protection of MEMS which successfully satisfies the requirements stated above. Metal microstructures, created through the reflow of solder, are successfully used to armour and protect delicate silicon MEMS suspensions. A brittle silicon-silicon impact is replaced with a ductile metal-metal impact. The metal protects the silicon from fracturing at the point of impact during a high-shock event and absorbs a significant proportion of the collision energy through plastic deformation. A model suspension system is used to assess the performance of metalarmouring as a MEMS shock-absorber. Two metal-bumper designs, surface-mounted solder bumpers and solder bumpers integrated into the sidewalls of the suspension system are fabricated and tested in a drop-test rig at acceleration levels of up to 6000g. The surface-mounted bumpers, formed by reflowing solder on metallised pads (plated on the suspension surface), were found to fail on impact at the pad-wafer interface. The integrated bumpers are designed to combat the short-comings of the surface-mounted bumpers. Two solder balls are reflowed in through-wafer conduits within the suspension sidewalls, creating substantial solder bumpers which are mechanically keyed in place. The integrated bumpers proved to be shear resistant and to double overall the shock resistance of the MEMS suspension.Open Acces

Autonomous Robotics in the AEC practice

In recent years, technical development in robotics has been enhanced by leaps forward in artificial intelligence and machine learning (ML). Today’s robots learn and optimize their motion, are remotely connected and ready for deployment, and can transfer learned models and behaviors between industries or applications.1 This paradigm shift and step change in available autonomy necessitates rethinking how robotics may impact the AEC industry. Until now, contractors and fabricators have mainly used robots to replace humans in the narrow opportunity presented by “Dull, Dirty, and Dangerous” tasks (the 3Ds)—repeated millions of times with little variability. However, AEC professionals are starting to explore robots’ ability to perform tasks that are “Specific, Sustainable, and Scalable” (the 3Ss). Robots complete specific tasks by producing one-off designs and sustainable tasks as they render viable reuse as well as material and waste reduction. Yet they maintain scalability by being able to effortlessly multiply into the hundreds or even millions. They are “smart” enough to work alongside humans, rather than replace them