Efficient path planning is essential in applications ranging from autonomous navigation to search  and rescue. Traditional algorithms, such as A*, are designed to find the shortest route between  two points, but real-world scenarios often involve uncertain target points, which can be simulated  through probability distributions.    We aimed to build on the A* algorithm to minimize distance when navigating towards a region  mapped with a probability density rather than a fixed point. Using MATLAB, we simulated  scenarios with varying region sizes, start and end positions, and obstacles. We also explored how  to adapt for multiple regions of interest by integrating another probability distribution when  determining the expected distance traveled. Our results showed reduced travel distances  compared to standard A*, specifically in the distance between the estimated target and the actual  goal point. This shows the potential of minimizing the distance traveled for path planning in  uncertain target regions. Future work could integrate hardware components, like GPS or a  software-defined radio (SDR) transceiver, to create more realistic regions of interest. We can also  focus on optimizing the time traveled, instead of the distance.

Tin electrodeposition is the process of positively charged tin ions moving through a chemical bath and depositing onto the negatively charged cathode, which has a wide variety of applications. In the context of advanced packaging, it can be used to plate solder which enables the formation of electromechanical joints between two substrates. Plating tin at finer pitches allows for more electrical connections to exist in a given area, increasing the number of potential connections and thus the I/O density. However, a robust plating setup is needed in order to plate tin at these pitches more consistently and uniformly. We performed a design of experiments to investigate how different variables affect the plating, as well as to determine which values for these variables create the most uniform and smooth surface. Specifically, we looked at how current density and pad size affected the plating thickness, plating rate, plating uniformity, and plated tin surface roughness. We measured the surface roughness and uniformity after one hour of plating for each sample at 5 different locations using a Keyence Laser Confocal Microscope. The uniformity was maximized at the current density of 0.2 amps per square decimeter and at the pad length of 200μm. With these values, the plating rate was calculated to be 16.07 micrometers per hour.

As the aerospace industry expands and space companies prioritize reusable, cost-effective systems, there is increasing demand for lightweight and efficient propulsion systems. One strategy for reducing engine mass is shortening the combustion chamber, which is possible if propellants mix more efficiently and combust over a shorter distance. The injector is responsible for mixing propellants. Additive manufacturing enables complex injector designs that improve mixing and reduce part count, replacing a coaxial rocket injector, traditionally made from hundreds of components, with a single printed part.  In this study, a single-element coaxial swirl injector was designed and fabricated via direct metal laser sintering additive manufacturing. Coaxial swirl injectors achieve high mixing efficiency through swirl-induced turbulence. To evaluate mixing in the flame, several laser absorption scans were taken and analyzed. This experiment was repeated on a coaxial shear injector under identical conditions and later compared to the swirl results. All testing was performed using gaseous methane and gaseous oxygen with a constant oxidizer-to-fuel ratio of 3.2. From the absorption plots, temperature and carbon monoxide (CO) mole fraction measurements were extracted and used to quantitatively compare mixing between the two injectors. Preliminary results show the swirl injector achieved earlier and more uniform mixing, with a shorter flame length than the shear design. These findings highlight the potential for shorter chamber length, reduced manufacturing complexity, and improved efficiency through optimized injector geometry and additive manufacturing-enabled production.