{"id":14407,"date":"2018-02-14T07:43:39","date_gmt":"2018-02-14T07:43:39","guid":{"rendered":"https:\/\/www.revoscience.com\/en\/?p=14407"},"modified":"2020-05-27T06:11:36","modified_gmt":"2020-05-27T06:11:36","slug":"graphene-toast-anyone","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/graphene-toast-anyone\/","title":{"rendered":"Graphene on toast, anyone?"},"content":{"rendered":"

Rice University scientists create patterned graphene onto food, paper, cloth, cardboard<\/em><\/strong><\/span><\/p>\n

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Rice University graduate student Yieu Chyan, left, and Professor James Tour. (Credit: Jeff Fitlow\/Rice University)<\/figcaption><\/figure>\n

HOUSTON \u2013 Rice University scientists who introduced\u00a0laser-induced graphene<\/u><\/a>\u00a0(LIG) have enhanced their technique to produce what may become a new class of edible electronics.<\/span><\/p>\n

The Rice lab of chemist James Tour, which once\u00a0turned Girl Scout cookies into graphene<\/u><\/a>, is investigating ways to write graphene patterns onto food and other materials to quickly embed conductive identification tags and sensors into the products themselves.<\/span><\/p>\n

“This is not ink,” Tour said. “This is taking the material itself and converting it into graphene.”<\/span><\/p>\n

The process is an extension of the Tour lab’s contention that anything with the proper carbon content can be turned into graphene. In recent years, the lab has developed and expanded upon its method to make graphene foam by using a commercial laser to transform the top layer of an inexpensive polymer film.<\/span><\/p>\n

The foam consists of microscopic, cross-linked flakes of\u00a0graphene<\/u><\/a>, the two-dimensional form of carbon. LIG can be written into target materials in patterns and used as a supercapacitor, an electrocatalyst for fuel cells,\u00a0radio-frequency identification (RFID) antennas<\/u><\/a>\u00a0and biological sensors, among other potential applications.<\/span><\/p>\n

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Rice University scientists experimented with various materials to create highly conductive laser-induced graphene, a foamy variant of the one-atom-thick form of carbon. Graphene burned into food could be used as radio-frequency tags for tracking or sensors to warn if the food is contaminated, according to Rice chemist James Tour. (Credit: Jeff Fitlow\/Rice University)<\/figcaption><\/figure>\n

The new work reported in the American Chemical Society journal\u00a0ACS Nano<\/u><\/a>\u00a0demonstrated that laser-induced graphene can be burned into paper, cardboard, cloth, coal and certain foods, even toast.<\/span><\/p>\n

“Very often, we don’t see the advantage of something until we make it available,” Tour said. “Perhaps all food will have a tiny RFID tag that gives you information about where it’s been, how long it’s been stored, its country and city of origin and the path it took to get to your table.”<\/span><\/p>\n

He said LIG tags could also be sensors that detect E. coli or other microorganisms on food. “They could light up and give you a signal that you don’t want to eat this,” Tour said. “All that could be placed not on a separate tag on the food, but on the food itself.”<\/span><\/p>\n

Multiple laser passes with a defocused beam allowed the researchers to write LIG patterns into cloth, paper, potatoes, coconut shells and cork, as well as toast. (The bread is toasted first to “carbonize” the surface.) The process happens in air at ambient temperatures.<\/span><\/p>\n

“In some cases, multiple lasing creates a two-step reaction,” Tour said. “First, the laser photothermally converts the target surface into amorphous carbon. Then on subsequent passes of the laser, the selective absorption of infrared light turns the amorphous carbon into LIG. We discovered that the wavelength clearly matters.”<\/span><\/p>\n

The researchers turned to multiple lasing and defocusing when they discovered that simply turning up the laser’s power didn’t make better graphene on a coconut or other organic materials. But adjusting the process allowed them to make a micro supercapacitor in the shape of a Rice “R” on their twice-lased coconut skin.<\/span><\/p>\n

Defocusing the laser sped the process for many materials as the wider beam allowed each spot on a target to be lased many times in a single\u00a0raster scan<\/u><\/a>. That also allowed for fine control over the product, Tour said. Defocusing allowed them to turn previously unsuitable\u00a0polyetherimide<\/u><\/a>\u00a0into LIG.<\/span><\/p>\n

“We also found we could take bread or paper or cloth and add fire retardant to them to promote the formation of amorphous carbon,” said Rice graduate student Yieu Chyan, co-lead author of the paper. “Now we’re able to take all these materials and convert them directly in air without requiring a controlled atmosphere box or more complicated methods.”<\/span><\/p>\n

The common element of all the targeted materials appears to be lignin, Tour said. An earlier study relied on\u00a0lignin<\/u><\/a>, a complex organic polymer that forms rigid cell walls, as a carbon precursor to\u00a0burn LIG in oven-dried wood<\/u><\/a>. Cork, coconut shells and potato skins have even higher lignin content, which made it easier to convert them to graphene.<\/span><\/p>\n

Tour said flexible, wearable electronics may be an early market for the technique. “This has applications to put conductive traces on clothing, whether you want to heat the clothing or add a sensor or conductive pattern,” he said.<\/span><\/p>\n

Rice alumnus Ruquan Ye is co-lead author of the study. Co-authors are Rice graduate student Yilun Li and postdoctoral fellow Swatantra Pratap Singh and Professor Christopher Arnusch of Ben-Gurion University of the Negev, Israel. Tour is the T.T. and W.F. Chao Chair in Chemistry as well as a professor of computer science and of materials science and nanoengineering at Rice.<\/span><\/p>\n

The Air Force Office of Scientific Research supported the research.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Rice University scientists create patterned graphene onto food, paper, cloth, cardboard HOUSTON \u2013 Rice University scientists who introduced\u00a0laser-induced graphene\u00a0(LIG) have enhanced their technique to produce what may become a new class of edible electronics. The Rice lab of chemist James Tour, which once\u00a0turned Girl Scout cookies into graphene, is investigating ways to write graphene patterns […]<\/p>\n","protected":false},"author":6,"featured_media":14409,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[],"class_list":["post-14407","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl.jpg",720,480,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl-150x150.jpg",150,150,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl-300x200.jpg",300,200,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl.jpg",720,480,false],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl.jpg",720,480,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl.jpg",720,480,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl.jpg",720,480,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl.jpg",720,480,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl.jpg",720,480,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl.jpg",600,400,false],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl.jpg",600,400,false],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl.jpg",720,480,false],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl.jpg",540,360,false],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl.jpg",95,63,false],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl.jpg",640,427,false],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl.jpg",96,64,false],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2018\/02\/0129_FOOD-5-web-2cph1xl.jpg",150,100,false]},"author_info":{"info":["Amrita Tuladhar"]},"category_info":"Research<\/a>","tag_info":"Research","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/14407","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=14407"}],"version-history":[{"count":0,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/14407\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/14409"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=14407"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=14407"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=14407"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}