Cyanobacteria, which changed the Earth's atmosphere from one that is oxygen-deprived to oxygen-rich, have recently been copied and produced as a micro-scale biological solar cell by British scientists. The size of the cell is similar to the iPad. The team believes that due to biodegradation, the cell can be used in developing countries which have lower budget for medical care. It can also function as a health tracker or wallpaper to monitor indoor air quality.

Cyanobacteria are microorganisms which gain energy from photosynthesis. They are nearly 3.5 billion years old and have been the earliest photosynthetic creatures to date. Generally, the biggest contribution of cyanobacteria is that they changed the Earth's atmosphere from one deprived of oxygen to one that is oxygen-rich, boosting the biodiversity of the planet. They also contributed to the near extinction of anaerobic organism, which significantly changed the formation of life form on Earth.

Currently, these microorganisms have another function. Led by Imperial College London, University of Cambridge and Central Saint Martins, a team of scientists have printed cyanobacteria onto electrically conductive carbon nanotube using an inkjet printer. Then, they printed the latter onto paper with the same method and discovered that cyanobacteria were alive through the printing process. Unlike traditional solar cell which can only function under light, this bio-solar cell is able to produce some electricity under darkness for about 100 hours.

▲ The bio-solar cell can be changed into wallpaper. (Source: Imperial College London)

Although their lifespan is largely shorter compared with traditional solar cell, the purpose of this bio-solar cell isn't to replace traditional technology or to be used in large-scale electricity production, according to Imperial College London researcher Andrea Fantuzzi. The advantage is that owing to biodegradation, the cell serves as a disposable solar panel and battery that can decompose in composts or gardens.

In addition, the low power output represents that this cell is suitable for small devices such as sensors, simple digital alarms and small LED lamps. In medical industry, this cell can also be used as the disposable paper sensor to monitor the blood sugar levels of patients with diabetes. This research was published in the journal Nature Communications.
 (Article Source: TechNews / Photo Source: Imperial College London)