Rapid hot embossing of polymer microfeatures

Although the hot embossing process is gaining popularity in molding polymer micro/nano structures, it needs a breakthrough improvement in reducing cycle time before it can become a mass-production process. In this study, an embossing tool with a rapid heating and cooling capability was investigated to reduce the cycle time. During the process, the embossing tool was rapidly heated to above the polymer softening temperature (in less than a couple of seconds), pressed against a room-temperature polymer substrate, and subsequently rapidly cooled for mold separation. Different miniaturized features including microsquare and hexagonal wells, microcircular holes, and submicron surface features were successfully produced using the new process with a total embossing cycle time around 20 s. The fatigue test result indicated that the new embossing technology is durable and reliable for microscale feature replication.