A Laser-Induced Graphene-Based Flexible Strain Sensor Using Tri-Ethylene Glycol/PDMS Composite

초록

Laser-induced graphene (LIG) has emerged as a compelling material platform for flexible electronics, enabling applications in strain and pressure sensing as well as physiological signal monitoring. The fabrication process leverages a photothermal mechanism in which laser irradiation converts a carbon-rich precursor into porous, three-dimensional graphene networks. A key challenge, however, is that widely used elastomers such as polydimethylsiloxane (PDMS) and Ecoflex possess insufficient carbon content for direct laser graphenization. Consequently, conventional flexible LIG devices rely on polyimide as the carbon source, requiring a subsequent pattern transfer step that degrades electrical conductivity. Moreover, the inclusion of polyimide particles compromises the mechanical flexibility and stretchability of the resulting device. To address these limitations, we introduce a composite of PDMS and triethylene glycol as a directly laser-processable substrate for strain sensing. The fabricated sensor exhibits markedly improved performance, achieving a gauge factor (GF) of approximately 175 alongside an operational strain range of up to 100%.

키워드