ObjectiveDevice LogicPressure Actuated Valve Test DesignObjectiveThe pressure actuated valve design was made to see if simple control mechanismscould be incorporated into a three-dimensional microfluidic system. While the two previous designs both contained elements of multi-dimensional flow, they lacked the ability to have this flow controlled to any real degree. Since the main purpose of this project was to eventually be able to make liquids flow in any hole and out any other, the valves were crucial for any real success.Device LogicThe beauty of this valve design is the simplicity of the mechanism that is used. A thin layer of PDMS is put over a layer that has lines filled with gas instead of fluid. Above the thin layer, where the gas line crosses under the fluid layer, a small gate is added that stops the flow of fluid when the gas line is pressurized. When the pressure is lowered in the lines, the thin layer flexes down, creating a gap for the liquid to flow through (Figure __). The overall layout of the design (Figure __) was chosen to fit with the preexisting packaging that was available. The T-section that was present in the second design was used because it offered a place where the fluid could flow in two different directions, and controlling the flow at this point would the first step in showing that fluid control could be achieved. Figure __ - A side view of the intersection point between the fluid layers and gas layersThe other line put into this design, which simply runs across the top layer,and contained two valves was added to show as a wayof showing, if the other section failed, whether the valves were to blame. This design is useful for several reasons, first of which was the aforementioned ease of design, and ease of understanding. This design is far easier to understand and use than the other designs that were looked into as possible choices. The other main reason this design was chosen was because it was the only one that we has that tools and materials to make with the time and monetary restraints that were present in the class. While some of the other designs may have been more advanced, and may have worked better, this design could actually be manufactured.Figure __ - This is a top view ofthe overall gas line setup. Green is top fluid, red is bottomfluid, brown is gas, yellow is interconnect, and dark blue is
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