One mask one exposure in-situ magnetic actuator fabrication method

Abstract

We demonstrate in-situ magnetic actuator fabrication technique via one-mask one-exposure method. A single magnetic microstructure or magnetic actuator is photopatterned from magnetic nanoparticles (MN) containing ultraviolet (UV) light curable resin in PDMS microfluidic channels. Oxygen inhibition layer generated from the PDMS surface allows magnetic microstructure to move and float without a sacrificial layer concurrently with the fabrication process. Thus, we only need one-time UV patterning with one-mask to fabricate a single complex magnetic actuator. We generated various magnetic structures such as both anchored and floating actuators with the above simple one-mask one-exposure system. These magnetic structures are actuated by external permanent magnet controlled outside of the channel. Overall magnetic actuator fabrication and control are take place in the same area without extra step to transfer the position from the fabrication site to the actuation site. Therefore, the entire process is very simple and fast enabling in-situ fabrication and real-time actuation.