From bacteria to mother-of-pearl<\/strong><\/h3>\nIn order to make the artificial nacre, Meyer and her team create alternating thin layers of crystalized calcium carbonate\u2014like cement\u2014and sticky polymer. They first take a glass or plastic slide and place it in a beaker containing the bacteria Sporosarcina\u00a0pasteurii,<\/em> a calcium source, and urea (in the human body, urea is the waste product excreted by the kidneys during urination). This combination triggers the crystallization of calcium carbonate. To make the polymer layer, they place the slide into a solution of the bacteria Bacillus licheniformis<\/em>, then let the beaker sit in an incubator.<\/p>\n <\/p>\nThe combination of the bacteria Sporosarcina pasteurii<\/em>, a calcium source, and urea triggers the crystallization of calcium carbonate, pictured above in extreme close up. (University of Rochester \/ J. Adam Fenster)<\/figcaption><\/figure>\nRight now it takes about a day to build up a layer, approximately five micrometers thick, of calcium carbonate and polymer. Meyer and her team are currently looking at coating other materials like metal with the nacre, and \u201cwe\u2019re trying new techniques to make thicker, nacre-like materials faster and that could be the entire material itself,\u201d Meyer says.<\/p>\nIn order to make artificial mother-of-pearl, Anne S. Meyer and her team use bacteria to create alternating thin layers of crystalized calcium carbonate and sticky polymer. Each layer is approximately five micrometers thick. (University of Rochester photo \/ J. Adam Fenster)<\/figcaption><\/figure>\nBuilding houses on the moon<\/strong><\/h3>\nOne of the most beneficial characteristics of the nacre produced in Meyer\u2019s lab is that it is biocompatible\u2014made of materials the human body produces or that humans can eat naturally anyway. This makes the nacre ideal for medical applications like artificial bones and implants, Meyer says. \u201cIf you break your arm, for example, you might put in a metal pin that has to be removed with a second surgery after your bone heals. A pin made out of our material would be stiff and tough, but you wouldn\u2019t have to remove it.\u201d<\/p>\n
And, while the material is tougher and stiffer than most plastics, it is very lightweight, a quality that is especially valuable for transportation vehicles like airplanes, boats, or rockets, where every extra pound means extra fuel. Because the production of bacterial nacre doesn\u2019t require any complex instruments, and the nacre coating protects against chemical degradation and weathering, it holds promise for civil engineering applications like crack prevention, protective coatings for erosion control, or for conservation of cultural artifacts, and could be useful in the food industry, as a sustainable packaging material.<\/p>\n
The nacre might also be an ideal material to build houses on the moon and other planets: the only necessary \u201cingredients\u201d would be an astronaut and a small tube of bacteria, Meyer says. \u201cThe moon has a large amount of calcium in the moon dust, so the calcium\u2019s already there. The astronaut brings the bacteria, and the astronaut makes the urea, which is the only other thing you need to start making calcium carbonate layers.\u201d<\/p>\nAssociate professor of biology Anne S. Meyer. Meyer and her colleagues are using bacteria to replicate the hierarchical, layered structure of nacre to produce a synthetic material with the strength and flexibility of natural mother-of-pearl. (University of Rochester photo \/ J. Adam Fenster)<\/figcaption><\/figure>\nEven beyond its qualities as an ideal structural material, nacre itself\u2014as any pearl jewelry owner knows\u2014is \u201cvery beautiful,\u201d Meyer says, owing to its stacked layers. Each stacked layer is approximately the same wavelength as visible light. When light hits the nacre, \u201cthe wavelengths of light interact with these layers of the same height so it bounces back off in the same wavelength as visible light.\u201d While the bacterial mother-of-pearl does not interact with visible light because the layers are thicker than natural mother-of-pearl, it could interact with infrared wavelengths and bounce infrared off itself, Meyer says, which \u201cmay offer unique optical properties.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"
Nacre, also known as mother-of-pearl, is an exceptionally tough natural material found in shells and pearls. Rochester biologists have developed an innovative method for creating nacre in the lab\u2014and maybe on the moon. <\/p>\n","protected":false},"author":912,"featured_media":375702,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[116],"tags":[38642,18722,37312,18572,16072],"class_list":["post-375202","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-sci-tech","tag-anne-s-meyer","tag-department-of-biology","tag-materials-science-program","tag-research-finding","tag-school-of-arts-and-sciences"],"acf":[],"yoast_head":"\n
糖心logoers create artificial mother-of-pearl using bacteria<\/title>\n \n \n \n \n \n \n \n \n \n \n \n \n\t \n\t \n\t \n \n \n \n\t \n\t \n\t \n