Abstract:
We designed nanoscale tools in the form of autonomous and remotely guided catalytically and
magnetically self-propelled micro- and nanotools. Asymmetrically rolled-up nanotools move in a corkscrewlike
trajectory, allowing these tiny tubes to drill and embed themselves into biomaterials (fixed HeLa cells
and tissues). First, we designed the smallest self-propelled nanojet engine (InGaAs/GaAs/(Cr)Pt) with
diameters in the range of 280–600 nm, which move in hydrogen peroxide solutions with speeds as high as 180
μm.s-1 and perform advanced tasks such as drilling into cancer cells. Also, we demonstrated that tubular fuelfree
Ti/Cr/Fe micro-drillers containing sharp tips can be applied for mechanical drilling operations of
porcine liver tissue ex vivo. An external rotational magnetic field is used to remotely locate and actuate the
micro-drillers in a solution with a viscosity comparable to that of biological fluids (e.g., blood).