In polymer microfluidic fabrication, bonding the polymer replicas with another substrate to create enclosed microfluidic channel is essential for success microchip fabrication. Various microfluidic bonding techniques have been reported for higher bonding strength and better stability. However, the microchip sealing from these bonding techniques are usually permanent which can not be open and re-assemble while accessing the sample inside the microfluidic is required. Polydimethylsiloxane (PDMS) is a widely used polymer material in microfluidic cell analysis due to its non-toxic and gas permeability advantages. In cell research, cells cultured inside the microfluidic device are usually need to remove from the chip for post bioanalysis or identification. Thus, in μTAS 2015, we present using magnetic nanoparticles (MNPs) embedded within the PDMS layer as high bond strength reversible bonding method for microchip applications.