Space stations and offshore oil rigs don’t have a lot in common, other than Wei-Chuan Shih.
Shih, an assistant professor of electrical and computer engineering with the University of Houston Cullen College of Engineering, has won two grants in recent weeks: one to develop an environmental monitoring system for space missions, the other to devise an oil leak detection tool for unmanned offshore rigs.
The environmental monitoring grant comes from NASA and its inaugural Space Technology Research Opportunities for Early Career Faculty grant program. Similar to the National Science Foundation’s CAREER Awards, this program is designed to support the space agency’s future science and exploration needs by investing in junior-level faculty. Only 10 of these grants were awarded, with other winners representing institutions such as the California Institute of Technology, Stanford University and the University of Michigan.
Testing for the presence of viruses and bacteria in a micro-gravity environment is a significant challenge, said Shih, especially if they are being looked for in water. "There’s no way you can process that sample. The water droplet will just float around," said Shih. "So we want to build a sensor inside a microfluidic chip. This will minimize the quantity of water and give us the advantage of very little sample preparation."
Though the system is still being designed, Shih envisions it consisting of a microfluidics chip – essentially a self-contained system roughly the size of a smart phone – that can be hooked into a spacecraft’s or space station’s existing air and water filtration units. Inside the chip will be a gold nano-structured substrate that will capture viruses and bacteria it comes into contact with. The plasmonic properties of this substrate – plasmons being a type of electromagnetic wave – will support the recognition of these potential pathogens through various sensing and/or spectroscopy methods. Ideally, the system will be able to scan for bacteria and viruses automatically or will be simple enough to use with minimal training, Shih noted.
This grant is worth up to $600,000 over three years. Shih’s collaborators on this project include Cullen College assistant professors Debora Rodrigues with the civil and environmental engineering department and Jacinta Conrad with the chemical and biomolecular engineering department, as well as Duane Pierson and Mark Ott, microbiologists at NASA’s Johnson Space Center.
Shih’s second grant comes from the Gulf of Mexico Research Initiative (GoMRI), an independent body established in response to British Petroleum’s Deepwater Horizon oil spill.
Out of more than 600 applicants for funding in this round, GoMRI made only 19 awards. Shih’s grant, the only one to a Texas-based investigator, is valued at up to $740,000 over three years.
One of the challenges faced by the offshore petroleum sector is monitoring for oil leaks at unmanned drilling platforms. There are roughly 5,000 such platforms in the Gulf of Mexico alone, noted Shih. Current regulations require the companies responsible for these platforms to monitor them for oil leaks on a regular basis. This is typically done by visual inspection carried out on a helicopter – an imperfect solution at best. Helicopters are expensive to operate and cannot fly during the night or under inclement weather, while visual inspections can miss leaks.
In place, Shih is developing a compact, inexpensive system that uses hyperspectral imaging to detect oil on the water’s surface by searching for infrared radiation over large patches of water. Intense computation work will then allow he and his collaborators to separate the IR signal of oil from that of water.
"Scientifically, this is a new idea, doing hyperspectral infrared imaging," he said. "Oil has different surface properties than water. The emissivity [the ability to emit energy by radiation] of water is very different from oil. Our model allows us to extract the presence of oil on top of water."
According to Shih, some existing sensors can be employed to collect hyperspectral data, but logistical barriers make them impractical: They either require a bulky, power-hungry cooling system with cost in the neighborhood of $500,000 each, or require extensive scanning, and thus are very slow.
Once completed, platform owners/operators should be able to attach this new system to unmanned platforms. When oil leaks from a well, the sensor will detect it and alert a nearby manned platform, likely via Wi-Max, a version of Wi-Fi with a range of several miles. All told, Shih expects the system to cost in the $20,000 to $50,000 range.
Shih’s collaborators on this project include fellow Cullen College faculty members Craig Glennie, assistant professor of civil and environmental engineering at the Cullen College; and Zhu Han, assistant professor of electrical and computer engineering.