Browsing by Author "Yang, Kaichun"

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    Development of Multifunctional Laser-Induced Graphene Composites and Devices
    (2019-04-03) Yang, Kaichun; Nagarajaiah, Satish
    Graphene research has accelerated and the number of academic publications reporting the use of graphene was so substantial since it was isolated and characterized for the first time utilizing the mechanical exfoliation method by Geim and Novoselov in 2004. However, realistic applications of graphene-based materials are limited by the complex synthesis that requires strict experimental conditions or many time-consuming procedures for scale up graphene production. The emerging of Laser-Induced Graphene (LIG) provides a new facile pathway to obtain graphene in laboratory research or industry by roll-to-roll production. By virtue of its ultrafast photothermal reaction by CO2 infrared laser scribing on polyimide film, graphene patterns imprinted on the polyimide substrate adhere in a very short time, generally from seconds to minutes. Its easy and scalable synthesis, makes laser-Induced Graphene (LIG) a platform material for numerous applications. Despite its ease in synthesis, LIG’s potential for use in some applications is limited by its robustness and weak adherence on polyimide film where LIG grows from. An approach to stabilize LIG and reinforce its mechanical properties is in demand. In this study, using a simple infiltration method, the LIG composites (LIGCs) with varied physical properties are scribed onto various substrate materials. The porous LIG has good compatibility to diverse materials including commercial polymers and constructional materials such as polydimethylsioxane (PDMS), poly(methyl methacrylate) (PMMA) and Portland cement (PC). According to the different characteristics of matrix materials infiltrating into LIG porous structure, as-prepared composites exhibit adjustable electrical, mechanical and biological properties. The microstructure and level of oxidation of LIG can be controlled by using different laser parameters such as scanning speed, laser power and laser pulse density. The distinct properties including conductivity, capacitance, resistance, superhydrophobicity and antibiofouling of LIGCs are then modified. Based on LIGCs and their promising properties, several devices have been built in this study. Highly stretchable sensing devices and joule heating devices are developed by virtue of outstanding electrical properties of LIGs. Superhydrophobicity, superhydrophilicity and anti-biofouling surfaces of LIGs are adjusted by the chemistry and morphology of LIGCs surfaces yielding a good anti-biofouling device.
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    Laser-induced graphene sensors and methods of making and using same
    (2025-02-18) Tour, James Mitchell; Luong X, Duy; Yang, Kaichun; Arnusch, Christopher John; Singh, Swatantra Pratap; Thakur, Amit Kumar; Stanford, Michael G.; Li, John T.; Presutti, Steven E.; Rice University; B.G. NEGEV TECHNOLOGIES AND APPLICATIONS LTD., AT BEN-GURION UNIVERSITY; United States Patent and Trademark Office
    Gas sensors having laser-induced graphene (LIG) and/or LIG composites, and methods of making and using gas sensors having LIG and/or LIG composites.