"Green computing" came into reality. Cambridge University provided power to a computer through the photosynthesis of algae. We know that IOT devices need sustainable, affordable and decentralized power to provide power. Although the power consumption of a single IOT device is very moderate, ranging from micro watt to milliwatt, the number of IOT devices has reached billions and is expected to increase to one trillion by 2035, which requires a lot of portable energy, such as a battery or an energy harvester.
However, batteries rely mainly on expensive and unsustainable materials (such as rare earth elements), and the power will eventually run out.
The existing energy harvesters (such as solar energy, temperature and vibration) have a long duration, but they are not friendly to the environment. For example, harmful materials will be used in photovoltaic production.
So, is there an energy collection system that is portable, cheap and durable, and can protect the environment?
A research team at Cambridge University tells you: of course!
Here is the container containing cyanobacteria, which has powered a computer for up to a year!
The device is 6cm high, 3.1cm long and 2.3cm wide. It can be said to be very small. (I understand why this picture looks so big...)
Moreover, the materials it needs are simple, cheap and recyclable: plastic, aluminum, cyanobacteria and water.
With this, why do you need a battery??
*1 day and night, with a super endurance of more than six months * this energy harvester is a bio photovoltaic energy collection system, which was created by professor Chris Howe of the Department of Biochemistry at Cambridge University and his colleagues. The title of this study is "powering a microprocessor by photosynthesis", and the paper has been published in energy & amp; Environmental Science Journal.
Thesis address: https://pubs.rsc.org/en/content/articlelanding/2022/EE/D2EE00233G
The researchers made a metal shell the size of an AA battery with aluminum and transparent plastic, and placed a group of cyanobacteria called PCC 6803, commonly known as "cyanobacteria". When cyanobacteria are exposed to sunlight, they can produce oxygen through photosynthesis.
Note: cyanobacteria flora (source: ScienceDirect)
During the blockade of the epidemic in 2021, the device stayed on the windowsill of the family of team member Paolo Bombelli and produced a small current through algae photosynthesis to continuously supply power to the microprocessor arm Cortex-M0 +.
Note: arm Cortex-M0 + microprocessor
Arm cotex-m0 + chip comes from chip manufacturer arm. They cooperate with the research team of Cambridge University to provide it with test equipment and cloud interface for data collection. This chip is not specially designed for research, but a microprocessor commonly used in Internet of things devices. Pico's CPU of raspberry pie is it.
Note: cyanobacteria power generation device for supplying power to ARM chip
The researchers thought that the system might stop working in a few weeks. Unexpectedly, it worked day and night for six months , and the cyanobacteria continued to generate electricity after the experiment.
So how does this device generate energy?
*2 the magical "alchemist" * in theory, there are two possible sources: either the cyanobacteria produce electrons by themselves, thus generating an electric current; Or they create conditions for the aluminum anode in the container to be corroded in a chemical reaction, resulting in electrons and currents. In this experiment, there was no significant degradation of the anode, so the researchers believe that cyanobacteria produced most of the current.
In recent years, algae has become a new favorite of biofuels. Algae can generate hydrogen, purify wastewater, remove carbon dioxide from the atmosphere and so on. They seem to be a great "alchemist" and have great potential to develop clean technology.
PCC 6803 used in this experiment is a strain of unicellular freshwater cyanobacteria, belonging to Synechocystis sp. like other plants, it can obtain energy from sunlight through photosynthesis and produce weak current.
Therefore, as long as the electrode is placed in the water tank, the generated current can be used as a battery. The processor of the Internet of things device only needs very weak power to drive, so it is very appropriate to use algae to power the Internet of things device.
During the experiment, the microcomputer driven by algae performed some basic operations. Taking 45 minutes as a cycle, it calculated the sum of continuous integers to simulate the calculation workload. It only consumed 0.3 MW of power and 0.24 MW of power for 15 minutes. The computer itself measures the current output by the device, which is stored in the cloud for researchers to analyze.
Note: Christopher Howe (left) and Paolo Bombelli (right), members of the research team, from the University of Cambridge
Although the current generated by this device is relatively weak, it is enough to charge some small electronic devices. However, it is far from enough to power an ordinary desktop computer. The actual energy consumption of a computer will vary depending on factors such as workload and service life. If a computer consumes 100 watts of power per hour, it will need about 333000000 "batteries" to run the computer. More power is needed to supply the equipment in the future.
At present, the scale of algae "battery" is a little small, but Christopher Howe is particularly proud of the endurance of the device. "This photosynthesis device will not run out as quickly as the battery." Compared with traditional batteries or solar energy, algae are less dependent on the environment and constantly use light as an energy source to provide continuous power.
The algae do not need to be fed. They can "produce" their own food during photosynthesis and collect energy from natural sunlight. Moreover, in the absence of light at night, the device can continue to supply energy by "eating" the electricity stored during the day. Algae can be divided into autotrophic type and heterotrophic type. The most common one is photoautotrophic type. That is to say, there is light.
* the concept of algae chip will be applied to more than 3 devices in the pond. It is likely that the next step in the research of algae chip is far more than that of the Internet of things . The Internet of things has a large power gap. It needs a continuous energy supply system such as algae bio power generation, rather than a battery that simply stores energy.
In recent years, the peak of carbon and the wind of carbon neutralization are very strong. Carbon fixation and emission reduction is a key link to achieve global carbon neutralization. For example, using algae photosynthesis to energize a machine and equipment belongs to the category of "green computing".
"Green computing" is understood that green simply means low-carbon and harmless, that is, environment-friendly, resource-saving and efficient recycling. Computing can be understood as including terminal equipment, servers and related systems combined with software and hardware.
Seaweed is a common marine organism, which appeared 3.5 billion years ago. Rounded, it is the topx that releases the most oxygen in the world. The utilization of algae energy belongs to "bio photovoltaic" (BPV), which is a biological way to use solar energy. It sounds like a fresh wind is about to blow across the industrial land. Humans use the energy generated by microorganisms through photosynthesis to sustain the equipment for the industry. I think, isn't it a waste of billions of years of energy generated by microbial photosynthesis? The hoe of reclamation should be waved more frequently.
Note: floating algae in pond
For example, the efficiency of algae production is not as low as that of solar panels, which are exposed to the sun by 20.0%. Of course, the solar panels are not as low as that of peacocks. This project obviously needs a solution.
The good news is that researchers have found algae that can produce higher current, and the cost is very low, so it is likely to achieve large-scale commercial applications in the next five years.
It is conceivable that in the near future, the vast sea area will be covered with huge lotus leaf shaped algae, whose identity is the mobile power station of offshore wind farms.
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Author Li Mei, Liu Bingyi
Editor: Chen Caixian