Microrobots propel through complex biofluids

Micro-/nanorobots hold great potential for biomedicine, as they can be wirelessly driven and controlled to navigate in biological fluids, tissues and possibly organs.

However, the propulsion of micro-/nanorobots has so far mainly been demonstrated in Newtonian fluids such as water; and the micro-propulsion in non-Newtonian fluids (nearly all biological fluids) remains relatively unexplored.

The overall goal of this project is to develop micro-/nanorobotic systems that can actively propel through non-Newtonian biological fluids to deliver drugs.

We will measure and model the active microrheology of biofluids, and optimize the shape and actuation parameters for microrobots to penetrate these biological barriers.

For the first time, we will demonstrate the long-range guidance of micro-robots to propel through an organ by a 3D ultrasound field generated by the acoustic hologram technology. The biocompatible microrobots will be steered ultrasonically in a urinary bladder and accumulate around a tumor.

They will then be driven with the combination of ultrasonic and magnetic fields to penetrate the viscoelastic mucus coating layer on the tumor and anchor to the tumor tissues for sustained drug release for cancer treatment.

The research will shed light to the micro-propulsion through complex biofluids and open up entirely new possibilities for minimally-invasive targeted drug delivery.