Thermally Controlled Localized Porous Graphene for Integrated Graphene‐Paper Electronics

Porous graphene (PG) devices fabricated in situ from polyimide (PI) adhered onto paper substrates provide a cost-effective and recycling-friendly alternative to re-engineer paper for liquid-based power sources and sensors. However, paper is generally damaged due to heating during the fabrication of PG devices. Here integrated graphene-paper electronics with exceptional thermal control through the proposed thermally localized laser graphitization (LLG) process is demonstrated, employing optimized ultrafast laser writing. LLG enables in situ fabrication of localized porous graphene (LPG) devices (>1775 K) on 65 µm thick PI tape adhered to paper without heating above 348 K. Laser parameters for LLG are predicted using an analytical temperature model and validated experimentally. The LLG is demonstrated by fabricating liquid electrolyte LPG micro-supercapacitors and humidity sensors on liquid susceptible paper. It is envisaged that the scientific concepts proposed and demonstrated here will expedite the development of low-cost, scalable, and chemically robust LPG devices on thermally sensitive substrates. Ministry of Education (MOE) Funding: This work is supported under the research collaboration agreement by Panasonic Factory Solutions Asia Pacific (PFSAP) and Singapore Centre for 3D Printing (SC3DP) (RCA-15/027). V.M.M. also acknowledges the financial support received through COLE-EDB, and MOE Tier 1 Grant RG192/17. S.W.L. acknowledges the support by Academic Research Fund Tier 2 from Ministry of Education, Singapore under ref. no. 2018-T2-1-045.