THE EFFECT OF SOLVENT RATIO ON THE ELECTRICAL CONDUCTIVITY OF HYBRID GNP/AG CONDUCTIVE INKS UNDER CYCLIC TORSIONAL STRESS

Abstract

Hybrid conductive inks composed of graphene nanoplatelets (GNP) and silver (Ag) nanoparticles are gaining significant attention for their enhanced electrical conductivity and mechanical properties, particularly in flexible electronics and wearable devices. The solvent ratio is decisive in determining the quality of the ink as it affects nanoparticle dispersion and stability. These factors, in turn, affect the ink's conductivity and overall performance. This study investigates the impact of solvent composition on the electrical performance of GNP/Ag hybrid conductive inks under cyclic torsional stress, specifically comparing the 10T:10B ratio to the 3T:3B ratio of terpinol to butanol. The curing process, a crucial step in ink preparation, was conducted at 250°C for one hour. Following this, electrical resistance and resistivity were measured using a Two-Point probe to assess the ink's performance. After 4000 cycles, the cyclic torsional test results showed that the 10T:10B formulation had significantly lower resistance (0.18 Ω) and resistivity (10.8 ×10⁻⁶ Ω.m) compared to the 3T:3B formulation (0.81 Ω and 0.48 ×10⁻⁶ Ω.m), indicating superior electrical performance. Prominently, the resistance of the 10T:10B sample was 77.8% lower, indicating more efficient conductivity and a stable and durable conductive network. These findings emphasise the importance of solvent composition and the curing process in optimising the performance and stability of conductive inks for high-stress applications.