The in-mold thermocompression bonding process of microfluidic chips based on the highly dynamic variotherm technology: Process characteristics

Thermoplastic microfluidic chips show broad development prospects in biomedicine, point-of-care testing, healthcare, and environmental monitoring owing to their advantages in cost, biocompatibility, etc. However, improving the production efficiency of microfluidic chips remains a key industrial challenge to promote the rapid popularization. In this work, we engineered a novel in-mold thermocompression bonding (IMTCB) process based on a highly dynamic mold temperature technology for rapid and mass production of microfluidic chips to overcome the limitations of the traditional thermocompression bonding process in bonding time and process stability. The orthogonal analysis results show that when the bonding strength is taken as the response variable the effect significance of the experimental factors listed from the top is: bonding temperature, bonding pressure, and bonding time. The bond strength increases exponentially with the increasing bonding temperature while increasing linearly with the increasing bonding pressure. The bonding strength can reach around 600 kPa with a microchannel deformation of less than 20%. The bonded thermoplastic microfluidic chips will be manufactured by the IMTCB process from raw materials within 5 minutes.