Ink evaporation on soft substrates for additive manufacturing of stretchable electronic devices : experimental studies

• Main Authors: Saengchairat, Nitipon, Chua, Chee Kai, Tran, Tuan
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Conference or Workshop Item
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering::Mechanical engineering::Prototyping; Ink Evaporation; Soft Substrates
• Online Access: https://hdl.handle.net/10356/88255; http://hdl.handle.net/10220/45705
• Institution: Nanyang Technological University

Additive manufacturing (AM) has emerged in various fields including prototyping, construction, biomedical science, and electronic fabrication. For manufacturing of electronics, several AM techniques have been developed, most notably droplet-based techniques such as inkjet and aerosol-jet printing. The progress in this field has been hindered due to the lack of appropriate materials, poor printing resolution, and lack of fundamental understanding on the deposition process of conductive materials. Typically for droplet-based printing, small droplets of a certain ink, i.e., micro- or nanoparticles suspended solvent, are ejected onto printed substrates. The ink droplets, after deposited on a substrate, evaporate leaving behind particles on the substrate. The evaporation process depends on various contributing parameters such as liquid properties, surface wettability, roughness, and stiffness. While this process has been extensively studied for rigid substrate, it has not been fully understood for soft substrates, which are relevant for fabrication of flexible and stretchable electronics. In this work, we study the effect of substrate's elasticity on evaporation process of suspension droplets. Variation in the elasticity plays a crucial role as it directly influences the morphology of the substrate at the triple-phase contact line, thus resulting in different deposited patterns of particles on the substrate. By fine-tuning the substract's elasticity, we expect that the electrical properties of the printed patterns can be manipulated.