The microfluidic system has the ability to hold and operate liquid flows varying in size from a few tens to several hundred micrometers. It is utilized more and more often in research disciplines including testing, medicine, testing and diagnostics, cell research, etc. In this study, we used flash foam (Flash Foam - FF) seal making technology to make low-cost microfluidic molds. The microfluidic structure was transcribed with Polydimethylsiloxane (PDMS) and closed with biosafety adhesive tape used in the PCR procedure. The results show that the microfluidic system has been successfully fabricated with the size limit of the microfluidic channel width of 50 µm. The cost of materials for a 6 x 6 cm microfluidic system is less than VND 150,000 (about ) with a manufacturing time of less than 3 hours. It can be seen that this is a potential method to manufacture low-cost microfluidic systems to promote research and application of microfluidic systems in the future.