Carbon-permeated magnetically actuated self-assembled cilia for heavy metal adsorption

Heavy metal contamination resulting from industrialization has become a pressing issue, prompting research on effective adsorbents for heavy metal adsorption and recovery. One promising approach involves incorporating magnetic particles into the adsorbent to enhance adsorption efficiency through magnetic manipulation. Moreover, among fluid-generating structures, magnetically actuated artificial cilia that can induce fluid flow through ciliary motion are notable examples. This paper proposes the first known study of magnetically actuated self-assembled artificial cilia (MSC), which generates fluid flow through magnetic actuation, with carbon permeation for heavy metal adsorption and desorption. We perform various experiments focusing on lead ion adsorption and desorption using the carbon-permeated MSC. Among carbon materials, MSC integrated with multiwalled carbon nanotubes (MWCNT) exhibits superior adsorption performance and capacity. The lead-ion adsorption performance of MWCNT-permeated MSC (M-MSC) is evaluated under varying environmental conditions, showing an increase in adsorption capacity of 11 times and a higher adsorption rate constant when actuated. The reusability of M-MSC is confirmed through repeated experiments, and an in situ channel experiment is implemented. In the future, the proposed carbon-permeated MSC is expected to be applied to remove heavy metal contaminants from fluid systems and specialized medical devices like hemodialysis machines.