USC Wrigley Institute

By: Cherie Ho

Hey! I’m Cherie and I’m a WIES Summer Fellow from Harvey Mudd College. I’m a part of LAIR, Lab for Autonomous and Intelligent Robotics. Over the years, our lab has been working with CSULB’s Shark Lab to study how we can use robots to track sharks! We were able to use multiple Autonomous Underwater Vehicles (AUVs) to track a single shark. My project this summer is to investigate how to use AUVs to track fish populations. I spent the last two weeks in Catalina deploying our robots on missions and maintaining them. Here’s the Iver, one of the underwater robot that we use for shark tracking!

Iver in Action!

To track sharks, the Iver is equipped with hydrophones that listen to acoustic pings the tags transmit. Once the Iver hears a ping, it calculates the range and bearing of the tag to estimate where the tag is. Then, it moves toward the estimated position and follows the tagged shark.

From this summer, I’ve learned that preparation is key to a successful robot deployment. Although the actual mission may take less than an hour, before that, we need to:
-assemble the Iver
-check that it is waterproof (all port holes plugged in)
-make sure the Iver’s propeller and fins are working
-calibrate sensors
-plan where the Iver can go (we don’t want to crash into kayaks and boats)

Many times, even though everything is checked and ready in the lab, the robot or the sensor may not work when we are about to deploy it at the dock. Therefore, we keep multimeters, power cables, soldering iron, glue gun and other electronics dockside to help us debug and fix the issues! We end up soldering wires a lot of times at the dock.

Aishvarya, another WIES fellow, soldering hydrophone wires

When everything is ready, the code is uploaded onto the Iver and we can deploy it! During the mission, we usually have someone keep track of where the Iver is. Under Catalina’s bright sun, trying to find the Iver in the water is like playing a game of Where’s Waldo.

Iver on a mission

We configure the Iver to return to its origin when the mission is over. However, sometimes the Iver may have stopped working (e.x. propeller broke) and is stuck out in the water. In that case, we use kayaks or boats to rescue the Iver.

Cherie (Me), Zunyan and Aishvarya rescuing the Iver

Once the Iver is rescued, we get the data off the Iver to process later.By the time everything’s done, it’s time for food!

My summer as a Wrigley Fellow has been a rewarding experience. The Wrigley Institute is an ideal location to conduct our research due to the number and variety of marine animals available. Being able to work in the WIES makes it easy for us to deploy robots after making code or hardware changes to collect immediate results. I have learned so much more about what is involved in field robotics and got a chance to work with some amazing people. Thanks for everything, WIES! ‘Til next time.

Cherie is a graduate student from Harvey Mudd, working under Professor Chris Clark. Her summer research focused on ‘characterizing fish population movement using a model based on artificial potential fields’.

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USC Wrigley Institute

By: Courtney Downes

Hello everyone! Courtney, here. I am a Summer WIES Sonosky Fellow, pursing a PhD in chemistry in Dr. Smaranda Marinescu’s lab at the University of Southern California.

Here I am working in the glove-box of our laboratory. Our chemistry is air-sensitive particularly sensitive to oxygen so we have to work inside the glove-box that has a nitrogen atmosphere.

The focus of our research is to develop new catalysts that can help make performing difficult reactions easier. Some of the most important reactions, such as CO2 reduction and water splitting, are challenging and the catalysts that can perform these reactions are typically noble metals so their scarcity and high cost limit their practical application. CO2 reduction and water splitting are very significant reactions in the quest to reduce and/or eliminate the world’s reliance on carbon based fuels and transition to renewable energy sources such as solar and wind. These reactions are usually associated with the process of artificial photosynthesis where raw materials like CO2 and water are converted into desirable fuels such as methanol and hydrogen gas.

My summer as a WIES Sonosky Fellow has been spent synthesizing and characterizing new catalysts for the hydrogen evolution reaction (HER), one half of water splitting. Hydrogen gas has the potential to be an important energy carrier. Most renewable energy sources are intermittent: the sun shines during the day and wind power is difficult to predict. If we use the sun as our major energy source, which sounds like a great idea since sunlight is free and abundant, what happens at night when energy demand is highest? The way to get around the intermittency of renewables is to store them on demand and then use the energy whenever it is needed.

Left: The black film in the dish is the synthesized nickel catalyst Right: I am preparing a sample of our catalysts for study using X-ray Photoelectron Spectroscopy

The ability to efficiently make hydrogen from water where all of the energy needed to drive the reaction comes from the sun would be a great step in combating climate change and moving away from fossil fuels. The sole product upon burning hydrogen is water resulting in a carbon free energy cycle.

Platinum is the state of the art catalyst for solar driven hydrogen production from water. However, platinum is very expensive and its availability is too limited to meet the global energy demands. Therefore, scientists are working tirelessly to develop new catalysts that use only earth-abundant and cheap materials to replace platinum in order to reduce the cost of solar driven water splitting devices in hopes of global deployment of these technologies.

USC ‘special edition’ electrochemistry set-up used to study our catalysts ability to generate H2 from water. The bubbles on the black electrode are hydrogen gas that our catalyst made during the experiment!

I have worked this summer on making catalysts using cobalt, nickel, and iron which are much more abundant and cheaper metals than platinum. The nickel and cobalt systems show great promise as our materials can successfully produce H2 from water with efficiencies ranging from 80-100%. As these are new materials, we have only investigated their ability to make H2 electrochemically. This means that we need to apply electrical energy for the reaction to occur.

The ultimate goal is to have the energy needed for this reaction be supplied by the sun, making the process solar driven. The ability of our catalysts to make H2 from water can easily be seen in the image above as the bubbles of hydrogen gas forming on the surface of the black electrode which has been modified with our catalyst. Future studies will look at using simulated sunlight to drive the catalytic reaction which will bring us one step closer to developing a practical direct solar to fuel converting device!

Courtney is a PhD student in the USC Department of Chemistry, in the lab group of Dr. Smaranda Marinescu. Her research focuses on the capture and H2 storage of solar energy production.

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