ETH Zurich and Technion researchers have developed an elastic “nanoswimmer” polypyrrole (Ppy) nanowire about 15 micrometers (millionths of a meter) long and 200 nanometers thick that can move through biological fluid environments at almost 15 micrometers per second. To propel the nanowire “tail,” two hinged ferromagnetic nickel sections of the wire undulate, controlled by an oscillating magnetic field, causing the tail to allow also undulate and move forward.
The nanoswimmers could be functionalized to deliver drugs and magnetically controlled to swim through the bloodstream to target cancer cells, for example. The research is described in ACS Nano Letters.
KurzweilAI has covered a number of similar devices, but they tend to have problems moving through body fluids, which are like molasses to something this small.
American Chemical Society | Toward nanorobots for drug delivery
Abstract of Undulatory Locomotion of Magnetic Multilink Nanoswimmers
Micro- and nanorobots operating in low Reynolds number fluid environments require specialized swimming strategies for efficient locomotion. Prior research has focused on designs mimicking the rotary corkscrew motion of bacterial flagella or the planar beating motion of eukaryotic flagella. These biologically inspired designs are typically of uniform construction along their flagellar axis. This work demonstrates for the first time planar undulations of composite multilink nanowire-based chains (diameter 200 nm) induced by a planar-oscillating magnetic field. Those chains comprise an elastic eukaryote-like polypyrrole tail and rigid magnetic nickel links connected by flexible polymer bilayer hinges. The multilink design exhibits a high swimming efficiency. Furthermore, the manufacturing process enables tuning the geometrical and material properties to specific applications.