Evaluating Mechanical and Conductivity of Graphene-Silver Hybrid Inks on Copper Substrate at Elevated Temperature

Abstract

This study investigates the effect of temperature on the damping behaviour, stiffness, and natural frequency of hybrid conductive ink (HCI) printed on a copper (Cu) substrate. The HCI comprises graphene nanoplatelets (GNPs), silver flakes (SF), and silver acetate (SA). The objective is to evaluate the HCI’s electrical conductivity and mechanical properties under varying thermal conditions. The HCI paste was formulated with a specified ratio of organic solvents, terpineol, and 1-butanol and cured in an oven at 260°C for 3 hours. The baseline droplet ratio was set at 1:1, and three Cu samples with varied HCl compositions were printed using a 60 µm mesh stencil process. The terpineol concentrations were changed while the 1-butanol droplet remained constant. The samples were then tested for electrical conductivity at room temperature using a two-point probe, in accordance with IEEE Std 118-1978, followed by mechanical behaviour testing using an ASTM E756-05 impact test. Furthermore, the samples were exposed to a range of temperature tests to evaluate mechanical and electrical conductivity under thermal stress. The results showed that the baseline composition exhibited minimal resistance and resistivity across the temperature range, with an average resistance of ? 0.2 ? and a resistivity of ? 0.8 ? · mm, respectively. The baseline composition also exhibited reduced stiffness and damping, with natural frequencies of 10.90, 1.40 kN/m, and 37.51 Hz across the samples. Therefore, the baseline composition exhibits relatively good electrical and mechanical properties for applications in flexible electronics.

ABSTRAK: Kajian ini meneliti kesan suhu terhadap sifat redaman, kekakuan, dan frekuensi semula jadi bagi dakwat konduktif hibrid (HCI) yang dicetak pada substrat kuprum (Cu). HCI ini terdiri daripada graphene platelet nano (GNP), serpihan perak (SF), dan perak asetat (SA). Objektif kajian ini adalah bagi menilai kekonduksian elektrik dan sifat mekanikal HCI di bawah keadaan haba berbeza. Pes HCI dibangunkan dengan nisbah tertentu pelarut organik, terpineol dan 1-butanol, dan dikeringkan dalam ketuhar pada suhu 260?C selama tiga jam. Nisbah titisan asas ditetapkan pada 1:1, dan tiga sampel Cu dengan komposisi HCI berbeza telah dicetak menggunakan proses stensil jaring 60 µm. Kepekatan terpinol diubah manakala titisan 1-butanol dikekalkan pada kadar yang sama. Sampel-sampel tersebut kemudiannya diuji bagi kekonduksian elektrik pada suhu bilik menggunakan probe Dua-Titik mengikut kod ujian piawaian IEEE Std 118-1978 dan diteruskan dengan ujian sifat mekanikal menggunakan ujian impak ASTM E756-05. Tambahan, sampel telah terdedah kepada pelbagai ujian suhu bagi menilai kekonduksian mekanikal dan elektrik di bawah tekanan haba. Dapatan kajian menunjukkan bahawa komposisi asas menunjukkan rintangan dan kerintangan minimum sepanjang julat suhu, dengan purata rintangan ? 0.2 ? dan kerintangan ? 0.8 ?/mm. Komposisi asas juga menunjukkan sifat mekanikal dengan kekakuan berkurangan, tingkah laku redaman, dan frekuensi semula jadi masing-masing sebanyak 10.90, 1.40 kN/m, dan 37.51 Hz merentasi sampel. Oleh itu, komposisi asas menunjukkan sifat elektrik dan mekanikal yang agak baik bagi aplikasi elektronik fleksibel.