Highly dynamic tempered in-mold thermocompression bonding of microfluidic chips: process characteristics and bonding performances

Abstract

Thermoplastic microfluidic chips show broad development prospects in biomedicine, point-of-care testing, healthcare, environmental monitoring, etc. However, improving the production efficiency of microfluidic chips remains a key industrial challenge to promote rapid popularization. In this work, we proposed a novel method for rapid and mass production of microfluidic chips based on a highly dynamic tempered in-mold thermocompression bonding (HD-IMTCB) process. The bonding temperature was tuned by a highly dynamic local variotherm technology based on thick film heaters. The results show that bonding temperature was the most significant factor for the bonding strength, and bonding time was the lowest one, which can be primarily optimized. With the bonding temperature reaching Vicat Softening Temperature and Glass Transition Temperature, the micro-channel deformation and bonding strength increased exponentially successively. The stable bonding strength reached 560–640 kPa with a microchannel deformation of less than 15%. The well-bonded thermoplastic microfluidic chips have been manufactured by the HD-IMTCB process from raw materials within 5 min, which not only improves the thermocompression bonding from a low-scale to a high-scale production model but also provides a blueprint for commercialization.

Keywords

• Microfluidic chips
• In-mold thermocompression bonding
• Bonding technology
• Manufacturing of microfluidic chips
• Micro-injection molding