Swimming Nanorobots Could Provide Targeted Drug Delivery

Nano-sized swimmer robots that move in an S-like, undulatory motion could move easily through body fluids to deliver drugs to their targets.

Developed by researchers at ETH Zurich (Switzerland) and the Israel Institute of Technology (Technion; Haifa, Israel), the magnetic nanoswimmers are made of composite, multilink nanowire-based chains with a diameter of 200 nm that move in an undulatory motion when influenced by an oscillating magnetic field. The design includes three links; one is an elastic, polypyrrole (Ppy) tail, and the other two are rigid magnetic nickel links. All three are inter-connected by flexible polymer bilayer hinges.

The researchers placed the nanorobots into a viscous fluid that was even thicker than blood. When they applied the oscillating magnetic field, the nanoswimmers moved at a speed of nearly one body length per second. According to the researchers, these specialized swimming strategies provide efficient locomotion for the nanorobots, with an added benefit of the magnetic field being that it can be used to direct the swimmers towards their targets. The study was published on June 1, 2105, in Nano Letters.

“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,” said lead author Bumjin Jang, MSc, of the ETH institute of robotics and intelligent systems. “The multilink design exhibits a high swimming efficiency. Furthermore, the manufacturing process enables tuning the geometrical and material properties to specific applications.”

Tiny robots could have many benefits for patients. For example, they could be programmed to specifically wipe out cancer cells, which would lower the risk of complications, reduce the need for invasive surgery, and lead to faster recoveries.

Related Links:
ETH Zurich
Israel Institute of Technology