Untethered micro- and nano-robots

Untethered, miniaturized robotic devices enable us to perform minimally invasive operations in complex 3D microenvironments. These remotely actuated operations can investigate and manipulate biological systems in an on-demand, flexible way. A variety of simple micromachines have recently been developed including microstructures controlled by oscillating magnetic fields, helical swimmers demonstrating corkscrew motion, thermally or magnetically actuated microgrippers, self‐propelled micromotors, and electrostatic impact‐driven microactuators. These machines can interact with objects both through physical contact and fluid flow generated around the body. The diagnostic and therapeutic potential of robotics in these microbiological contexts can be greatly enhanced with the development of compound micromachines that have multiple mechanisms working together to perform complicated tasks, such as the transport and release of therapeutic agents.

Ultrasound using moderate levels of pressure is regarded as a safe, non-invasive and relatively inexpensive procedure that is used extensively in clinical diagnostics and therapeutics.

We have developed a novel propulsion mechanism inspired by neutrophils rolling on the endovascular wall. Neutrophils undergo tethering, rolling, adhesion and crawling, before transmigrating into the diseased tissue

We have fabricated multi-functional compound micromachines in our lab using 3D direct laser writing and selective physical vapour deposition of magnetic materials.

Nature has inspired the fabrication of many mobile micromachines used in minimally invasive biomedical applications. However, there are certain design and material limitations associated with these simple micromachines which effect their manoeuvrability in complex environments.

Magnetic untethered micro-robots perform 3D navigation in various liquids under low-strength rotating magnetic fields by converting rotational motion to translational motion.