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MA04.11.01 : Laminated Object Manufacturing of 3D Printed Laser-Induced Graphene Foams

5:00 PM–7:00 PM Apr 5, 2018

PCC North, 300 Level, Exhibit Hall C-E

Description
Duy Luong1 Ajay Subramanian1 James Tour1

1, Rice University, Houston, Texas, United States

Graphene, a two-dimensional (2D) nanomaterial consisting of a monolayer of sp2 hybridized carbon atoms, has attracted recent interest due to its unique material properties, notably its high electrical and thermal conductivities and exceptional mechanical strength. In order to pursue high mass and volume demanding applications, it is necessary to integrate the properties of 2D graphene into macroscopic, three-dimensional (3D) structures. Several different methods have been developed to produce 3D graphene macrostructures, dubbed graphene foams (GF). The current fabrication process of graphene foam can be categorized in one of two categories: 1) growth of graphene in porous metal foam and 2) printing and reduction of graphene oxide (GO) dispersion. A direct approach without the need of metals or graphene oxide, or that is not made from graphite using wet chemistry, would be desired. Laser induced graphene (LIG), a graphene structure synthesized by a one-step process through laser induction of commercial polyimide (PI) film in ambient atmosphere, has been shown to be a versatile material in applications ranging from energy storage to water treatment. However, the major drawback of this material is its limitation in the 2D form on the PI substrate. In this study, we have developed a 3D printing process of LIG foams based on laminated object manufacturing, a widely-used additive manufacturing technique. We also developed and show here a subtractive laser milling process to add further refinements to the 3D structures. By combining both techniques, we are able to print various 3D graphene objects. The LIG foams show good electrical conductivity and mechanical strength, as well as viability in various applications of energy storage and flexible electronics applications. This includes a Li-ion capacitor where the LIG foam anode has a total gravimetric capacity of 345 mAh g-1, which is 95% of graphite's theoretical capacity. It has a comparable full cell energy density of 64 Wh kg-1. As a pressure sensor, an LIG composite device is able to record arterial pulses waveforms with a clear dicrotic notch.

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