91原创

The engines behind the large fuel cell are tiny living organisms called microbes that are able to use ocean carbon to create electricity. PODPower harnesses that electricity to activate and charge various sensors and other research devices in the ocean.

Ocean sensors give scientists a window into the depths of the Earth鈥檚 largest bodies of salt water. They clue researchers into temperature, how salty the water is, how high ocean waves are, and even how marine life behave beneath the surface.聽

Usually, these sensors need batteries or long underwater cables to work. And when a battery runs out or a cable frays, researchers have to replace them. It鈥檚 expensive and can disrupt important data collection.聽

That鈥檚 where the PODPower comes in.

鈥淭he idea is that you could do turtle monitoring programs or sensing of other marine organisms,鈥� said , environmental science and technology professor at the University of Maryland and the lead researcher on the project. 鈥淎ny sort of device that you would need to do research or draw electricity in the open water could be powered by this microbial system. We're creating renewable energy from the microscopic organisms that are in the ocean at the exact place where an energy source is needed.鈥�

Over the last 1.5 years, Lansing鈥檚 research team worked to 鈥渃oax鈥� freshwater microbes into adapting to a more saltwater, marine environment. Over time, Biddle said, the microbes adapted and are able to produce the chemical compound acetate from digesting the marine organics, like they could in digesting organics in freshwater.

鈥淢icrobes are little engines and it seems like they can do almost anything we want them to do,鈥� Biddle said. 鈥淚t鈥檚 a matter of learning how to coax them into doing what you want them to do, and trying to keep them alive and working.鈥�

The PODPower uses two chambers near its top that act like manta ray gills, inhaling water and trapping particles like zooplankton, phytoplankton and detritus that are then fed to a fermenter. The fermenter breaks down the organic matter into acetate, which is fed to another set of microbes in the fuel cell that move electrons from inside the cell onto a direct circuit outside the cell, creating an energy circuit, which can power ocean sensing devices.聽

, an associate professor of mechanical and aerospace engineering at George Washington University, helped design the collection system for the PODPower that filters small particles out of ocean water, taking in biological organisms like algae and passing them to the fermentation microbes, while allowing sand and silt 鈥� particles that are not organic matter 鈥� to pass right through.

鈥淲e tried to mimic the complex mouth structures of filter-feeding fish like manta rays to scavenge particles from seawater as passively as possible,鈥� Rau said. 鈥淭he collection system is designed to work passively with the ocean currents, so as the currents move through our devices, they extract the particles and then feed them to the microbes downstream.鈥澛�

Rau said the filter-feeding-inspired technology works well, but still 鈥渇alls short鈥� in areas where the water has few particles. He hopes further advancements will fix this. And future improvements to the technology can shrink the unit smaller and smaller while still producing energy outputs. Think of computers from the 1950s and how much bigger they were compared to now.

鈥淥riginally, those took up entire rooms and can now fit in our pockets,鈥� Rau said. 鈥淲e'll see through further research and development how small we can shrink this technology."聽

What Rau said resonated with TreVaughn Ellis, a second-year doctoral candidate in the 91原创 marine biosciences program. Ellis is monitoring the microbes in the PODPower鈥檚 vicinity, seeing how the surrounding microbes interact with the device鈥檚 microbial community.

鈥淪cience is about daring to do things that are outlandish or don鈥檛 seem feasible,鈥� Ellis said. 鈥淚鈥檓 thankful to be a part of it. I think it鈥檚 courageous what鈥檚 going on and I think that鈥檚 needed in science.鈥澛�

The PODPower project is a partnership between the University of Maryland, Johns Hopkins University, Harvard University, George Washington University, Oregon State University, 91原创, Battelle, and Yokogawa of America Inc.聽