Highly-Parallel Magnetically-Actuated Microvalves

This project aims to develop highly-parallel, magnetically-actuated microvalves using CMOS- compatible technology. Current state-of-the-art microvalve technologies require extensive supporting experimental apparatus and do not yield true lab-on-a-chip functionality. Here, the focus is placed on true chip-scale valve arrays based on low-power, on-chip magnetic coils which are used to actuate 100 micron diameter magnetic spheres that serve as the valve sealing surface. Prior studies of magnetic bead manipulation by planar coils, spin-valve arrays, and rotating magnetic fields have focused on the transport of small 1~50 micron diameter microbeads. In this work, the paramagnetic beads are magnetized using an external permanent magnet, allowing milliampere-level currents to generate large bipolar actuation force for valve opening/closure. The magnetically-actuated valves are self-assembled over each coil in a large chip-scale array by dispersing beads onto the chip and magnetically trapping a bead on top of each valve seat. Successful development of this technology will have various applications in parallel chemical synthesis and bioanalysis devices.


  • Pauline (JoJo) Chang
  • Frank Chang
  • Mischa Megens


  • P.J. Chang et al, “Magnetically-actuated picoliter reactor array”, Proceedings 2013 International Conference on Microtechnologies in Medicine and Biology, Marina Del Rey, CA, 2013, pp. 22-23.
  • Chang, P.J.; Yung-Yuan Kao; Mei-Lin Chan; Megens, M.; Horsley, D.A, “Low-power magnetically-actuated microvalves for highly parallel microfluidic automation,” Sensors, 2012 IEEE , vol., no., pp.1,4, 28-31 Oct. 2012
    doi: 10.1109/ICSENS.2012.6411397

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