Spatiotemporally controlled electrodeposition of magnetically driven micromachines based on the inverse opal architecture

摘要

We describe a double template-assisted electrodeposition of porous metal microstructures. The method combines two-dimensional photolithography and electrophoretic assembly of polystyrene beads, in order to confine the electrochemical growth of a porous magnetic cobalt-nickel alloy within well-defined microscale boundaries. Polystyrene beads are electrophoretically deposited onto a sulfonate derivatized gold substrate where a patterned photoresist layer (first template) is applied. The polystyrene beads trapped in the first template act as the second template, and cobalt-nickel alloy is electrochemically grown through the voids between the beads. After removal of both templates, magnetic microstructures with well-defined shapes and porosity are successfully obtained. Additionally, we demonstrate the capabilities of these magnetic microstructures as wireless cargo microtransporters by loading their pores with a stimulus-responsive hydrogel. Magnetic manipulation experiments are also demonstrated.