A Binghamton University engineering researcher designed a biological solar cell that’s a million times more effective than current technology. Preliminary data on Seokheun “Sean” Choi’s next advancement is a thousand times better than that. His cell also works in the dark, and is self-sustaining.
The new designs don’t make biological solar cells practical, yet. But they do take them out of the realm of “absurd” and place them squarely in the realm of “someday soon.”
Here’s the challenge:
Current photovoltaic cells generate watts of energy per square centimeter. A solar chip about the size of your fingernail can power a simple handheld calculator. Existing biological cells — which use photosynthesis to generate electricity — produce picowatts per square centimeter — a trillionth of a watt. To power that same calculator, the cells would stretch 20 meters wide and from Binghamton to Ireland. Absurd.
Choi’s first biological solar cell produces a million times more energy, microwatts per square centimeter, so the calculator could operate with a solar panel that fits on a trailer home roof — just 20 meters by 5 meters. His findings were recently published in the Royal Society of Chemistry’s journal Lab on a Chip.
And Choi’s latest experiment churns out milliwatts per square centimeter — reducing the calculator’s solar panel to a backpack-sized 8 inches by 20.
That brings it into the range of practical application, says Hongseok “Moses” Noh, an engineer and professor at Drexel University who specializes in lab-on-a-chip technology and applications. “Milliwatt power should be sufficient to meet those eneeds,” Noh says. “But the device, so far, is too big for hand-held systems, honestly.”
If Choi can reduce the cell to a tenth of its size while maintaining milliwatt power density, it would be enough to power hand-held blood analysis devices or air-testing machines. “This is one of very few miniaturized bio-solar products,” Noh says, and it’s worth following Choi’s progress.
What makes Choi’s approach different? Existing biological solar cells use a thin strip of gold or indium tin oxide as an anode between the bacteria and an air cathode. Not very efficient, and the bacteria eventually die because they lack air.
Choi uses a carbon anode immersed in the bacteria-laden fluid — a pretty peridot green in a lab flask. More efficient, and because the solution has access to air, it’s self-sustaining. It also uses the plant’s natural respiration to draw energy from the sugars in the cells to keep power up even if light is low.
Choi, an assistant professor of electrical and computer engineering, says he doesn’t understand why one form of cyanobacteria works better than another, or why a mixture of cyanobacteria and heterotrophic bacteria work even better than a single variety. His last biology class was in high school.
“I have no idea about microbiology; I just bought the bacteria and followed the instructions to culture it,” he says. But millions of bacteria species abound, and he plans to experiment to find the most productive combination.
Or, he suggests, he might work with bioengineers to develop a bacteria with its photosynthetic engine on the cell’s surface instead of deep in its heart. That would be another order of magnitude more productive because less energy would be wasted just going from the heart of the cell to its exterior. He has received seed funding from Binghamton’s Transdisciplinary Area of Excellence in smart energy to continue this work.
Choi says he’s confident he’ll eventually reach watt-level energy density, comparable to photovoltaic cells. “I can get that,” he says. “We have room for improvement.”
Todd R. McAdam | Binghamton University - discovere-e
Improved stability of plastic light-emitting diodes
19.04.2018 | Max-Planck-Institut für Polymerforschung
Intelligent components for the power grid of the future
18.04.2018 | Christian-Albrechts-Universität zu Kiel
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
In the fight against cancer, scientists are developing new drugs to hit tumor cells at so far unused weak points. Such a “sore spot” is the protein complex...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
20.04.2018 | Physics and Astronomy
20.04.2018 | Interdisciplinary Research
20.04.2018 | Physics and Astronomy