Flow regulation and drug delivery in bio-microfluidics using macro-porous ferrogel

We present the fabrication and application of a magnetically actuated, macro-porous, drug–delivery hydrogel exhibiting significant reversible volume change (down to 55% of its original size) in response to a small magnetic field (23 Gauss) from a permanent magnet. When integrating the hydrogel in a microchannel, the system demonstrates a magnetically regulated flow dynamics, showing a wide range of controllable flow rate from 10 to 100 µL/s. It is fabricated via a straightforward and economical process in which macro-pores are incorporated into the hydrogel by generating micro-bubbles during its crosslinking process. The resulting hydrogel enables simultaneous control over liquid flow and drug release rate.