Researchers took inspiration from how tree frogs and insects attach their feet to submerged leaves to create a one-step method to grow graphene and transfer it onto another material.
The new method allows the thin and super-strong material to be transferred using stiff substrates such as silicon, a feat that had never been accomplished in the past, a National University of Singapore news release reported.
The method marks the first time graphene has been both grown and transferred on a "silicon wafer." The technology could be used in "optoelectronic modulators, transistors, on-chip biosensors and tunneling barriers."
Graphene is of high interest to researchers because it has impressive electrical, optical and mechanical qualities. Graphene could also be used for touchscreen panels on electrodes. Researchers have been on the hunt to find an efficient method for growing the material.
"Although there are many potential applications for flexible graphene, it must be remembered that to date, most semiconductors operate on "stiff" substrates such as silicon and quartz," Professor Loh Kian Ping, head of the the Department of Chemistry at the NUS Faculty of Science, said in the news release. "The direct growth of graphene film on silicon wafer is useful for enabling multiple optoelectronic applications, but current research efforts remain grounded at the proof-of-concept stage. A transfer method serving this market segment is definitely needed, and has been neglected in the hype for flexible devices."
The team got the idea for the method by looking at the way frogs and beetles attach their feet to submerged leaves in a process called "face-to-face transfer."
Doctor Gao Libo, first author of the paper on the subject, grew graphene on a "copper catalyst layer coating a silicon substrate." After the substance is grown the researcher can "etch away" the copper and the graphene will be held in place by bubbles that create "capillary bridges." Beetles and frogs exhibit similar bubbles around their feet when clinging to an underwater leaf. After this has been completed the graphene can be attached to a silicon layer.
The discovery greatly widens the number applications for graphene.
