A discovery 15 years ago was finally applied. Recently, a research team from the Department of Electrical and Computer Engineering, Department of Microbiology, Department of Chemistry, Institute of Applied Life Sciences and Department of Biochemistry and Molecular Biology at the University of Massachusetts (Amherst) An "air generator" called "Air-gen" came out. This device uses a natural protein produced by bacteria to successfully generate electricity using moisture in the air, which may have a significant impact on renewable energy, climate change, and medicine. On February 17, 2020 local time, Nature published a paper by the research team titled "Power generation from ambient humidity using protein nanowires." Harvesting protein nanowires from Geobacillus As we all know, some of the current common power generation technologies-such as solar cells, thermoelectric devices, and mechanical generators-have certain requirements for the environment. In fact, this limits their potential for continuous power generation. At the same time, although the power generation technology based on moisture in the air provides us with a new idea, but due to the lack of a continuous conversion mechanism, this technology can only produce intermittent energy bursts, each time not exceeding 50 seconds. Based on this, the above research team harvested protein nanowires from Geobacter sulfurreducens. The so-called Geobacillus, or Geobacteriaceae bacteria, is a very important dissimilatory Fe (â…¢) reducing bacteria, widely distributed in the Fe (â…¢) reducing environment, such as freshwater sediments, organic matter or heavy metal contaminated groundwater sediments, etc. Important bioremediation function. Fifteen years ago, Derek Lovley, one of the lead authors of the paper and microbiologist, discovered that Geobacillus can transfer electrons from organic substances to metal compounds such as iron oxides. In fact, many bacteria can make protein nanowires and transfer electrons to other bacteria or their environment, and it is precisely this electron transfer that forms a tiny current-it can be said that this discovery was developed by Air-gen Foundation. According to the paper, the research team made the thin-film device Air-gen from the protein nanowires harvested from Geobacillus, which produced continuous power in the surrounding environment-a continuous voltage of about 0.5 volts on a 7-micron thick film , The current density is about 17 microamperes per square centimeter. If multiple thin film devices are connected to linearly amplify the voltage and current, power can be supplied to the electronic equipment. Specifically, the bottom of the protein nanowire film is on the electrode, while the smaller electrode covering only part of the nanowire film is on the top. It is the electrical conductivity and chemical properties of the protein nanowires that are coupled with the pores between the nanowires in the membrane to establish the conditions for generating current between the two electrodes. The figure below is a transmission electron microscope image and structure diagram of a protein nanowire device. Best results when the air humidity is 45% In 2018, LiuXiaomeng, a member of the research team, discovered that sometimes isolated nanowires spontaneously generate current. Later, LiuXiaomeng and his tutor YaoJun (the other main author of the paper) found that when the nanowire film is sandwiched between two gold sheets that serve as electrodes, it can continue to produce at least 20 hours of current. Subsequently, they found through experiments that when they placed the nanowires in a very low humidity environment, the current would be significantly reduced. So this shows that the humidity of the air contributes to the release of electrons. Therefore, the research team applied this discovery to the development of Air-gen-the driving force of its power generation process is precisely the gradient change of the humidity naturally formed in the film when the film is exposed to the air. The figure below records the voltage (black curve) and the relative humidity (blue curve) of the device generating electricity continuously for more than two months (1500 hours). It is worth mentioning that the research shows that when the air humidity is 45%, Air-gen power generation can achieve the best results. As shown in the figure below, when the relative humidity is about 45%, the top of the device is covered with plastic wrap, and its continuous current output will be interrupted (black arrow) and will continue in this state (gray area) until the plastic wrap is removed. The moment the plastic wrap is removed, the current will return to its original value (blue arrow). At the same time, this new technology is pollution-free, renewable, and low-cost. It can generate electricity in areas with extremely low humidity, such as the Sahara Desert, and can even work indoors. JunYao, one of the authors of the paper, also mentioned: We are actually using thin air to generate electricity, Air-gen can produce clean energy 24 hours a day. This is by far the most amazing and exciting application of protein nanowires. Start a new era of protein-based electronic devices In addition, the researchers said that the current generation of Air-gen equipment can provide power for small electronic devices, and they hope that this invention will soon be put into commercial use. They next plan to develop a small Air-gen "patch" to power electronic wearable devices such as health and fitness monitors and smart watches, reducing their need for traditional batteries. They also hope to apply Air-gen to mobile phones, users can avoid the trouble of regular charging. However, the team's ultimate goal is to manufacture large-scale systems. JunYao stated: For example, the inclusion of Air-gen in wall paint to support home power supply, or the development of independent aerodynamic generators to power the grid. Once our wire production reaches industrial scale, I hope that we can make large systems that can make a significant contribution to sustainable energy production. At the same time, in order to continue to advance the practical application capabilities of Geobacillus, DerekLovley and his team have also recently developed a new microbial strain that can mass produce protein nanowires faster and cheaper: We have turned E. coli into a protein nanowire factory. With this new scalable process, protein nanowire supply will no longer be a bottleneck. As mentioned above, the research team members have different backgrounds, so this is undoubtedly an unusual interdisciplinary cooperation, which is an important step in the direction of manufacturing new energy. However, as JunYao said: This is just the beginning of a new era of protein-based electronic devices. 48 Mosquito Netting Hebei Charlotte Enterprise Co., Ltd. , https://www.cnscreening.com
"Air generator" boarded "Nature": Geobacillus produces protein Saha