2D Nanomaterials wrapped Janus micromotors with built-in multiengines for bubble, magnetic, and light driven propulsion

Graphene oxide, graphdyine oxide, and blackphosphorus coated micromotors integrating "three engines" for motion control using different stimuli such as chemical fuel, light, and magnetic fields are described. Micromotors can be massproduced by wrapping gold-sputtered polystyrene microspheres with the 2D nanomaterials, followed by simultaneous assembly of Pt or MnO2 nanoparticles (NPs) as bubble (catalytic)-engines, Fe2O3 NPs as magnetic engines, and quantum dots (QDs) as light engines. The design and composition of micromotors are key to get the desired propulsion performance. In bubble-magnetic and bubble-light mode, a built-in acceleration system allows micromotor speed to be increased up to 3.0 and 1.5 times after application of the magnetic field or light irradiation, respectively. In the bubble-magnetic-light mode, such speed increase can be combined in a single unit for on-demand braking and accelerating systems. Fluid dynamics simulations illustrate that such adaptative behavior and improved propulsion efficiency is produced by a better distribution of the fuel and thus energy propelling the micromotor by activation of the magnetic and/or light engines. The new micromotors described here, which combine multiple engines with functional nanomaterials, hold considerable promise to develop novel nanovehicles with adaptative behavior to perform complex tasks in lab-on-a-chips or dynamic micropatterning applications.Ministerio de Ciencia e InnovaciónComunidad de MadridEuropean Commissio