Nanocilia In article number 2200185, Hoon Eui Jeong and co-workers develop a programmable self-assembly strategy that can direct magnetic nanoparticles into a highly ordered, field-responsive, artificial nanocilia array. The self-assembled nanocilia can maintain their structural integrity through the interplay of interparticle interactions. Interestingly, the nanocilia can exhibit a responsive actuation motion through “rolling and sliding” between assembled nanoparticles.