Laser-Induced Graphene from Commercial Inks and Dyes

Unlike traditional additive techniques, laser-induced graphene (LIG) is obtained by converting a polymer precursor into conductive carbon patterns through laser-induced pyrolysis. This method is unique in that it does not require a mask or additional chemicals. LIG is used in applications such as stretchable electronics, soft actuators, chemical and physical sensors, energy applications, and more.^1-3
We present a radically different class of new precursors for LIG, distinct from polymers: inks and dyes. The identification of specific organic dyes used in commercial markers shows that the aromatic structure combined with high thermal stability (residual weight > 20% at 800°C) are key factors for laser-induced pyrolysis. Eosin Y is identified as an excellent LIG precursor, comparable to well-known polyimides. The unique properties of the dyes allow them to be dispersed in various media, such as acrylic paint. A versatile "Paint & Scribe" methodology is presented, which allows the integration of LIG tracks on any wettable surface, and in particular on printed and flexible electronics. A process for obtaining free-standing and transferable LIG is demonstrated by dissolving acrylic paint in acetone and floating the LIG in water. This advancement opens new avenues for various applications that require a transfer process of LIG.
References
(1) Ye, R.; James, D. K.; Tour, J. M. Adv. Mater. 2019, 31, 1803621.
(2) Dallinger, A. et al. ACS Appl. Mater. Interfaces 2020, 12, 19855
(3) Bressi A.C. et al. ACS Appl. Mater. Interfaces 2023, 12, 19855.