Highly efficient chemically-driven micromotors with controlled snowman-like morphology

Abstract

We report the synthesis of silver-based Janus micromotors that self-propel at 3.5 μm s⁻¹ and speed up to 45 μm s⁻¹ in 0.044 and 1.5 mM of H₂O₂, respectively, via ionic diffusiophoresis. Morphology optimization further accelerates the speed to 90 μm s⁻¹, which leads to a force of 1 pN and a power of 0.1 fW, similar to biomolecular motors. Their efficiency reaches 10⁻⁵, at least two orders of magnitude higher than other chemically-driven micromotors. These micromotors hold great promises in various applications.