Amirreza Aghakhani (University of Stuttgart, Germany)

Acoustic microrobots
Untethered microrobots have significant applications in medical interventions such as targeted drug delivery. I will present a new class of acoustic microrobots that offer high locomotion speeds and good steering capability for navigating on both flat and curved surfaces. These acoustic microrobots contain a trapped air bubble to harness acoustic waves for propulsion at high speeds and could generate a thrust force of about two to three orders of magnitude higher than that of microorganisms such as algae and bacteria. Then, I will show how their superior propulsion capabilities allow locomotion in complex biological fluids, such as blood and mucus, which have non-Newtonian fluid behavior. These acoustic microrobots (length scale of ~25μm) were 3D microprinted in small batches using a 3D microprinting system based on the two-photon polymerization (2PP) technique. Lastly, I will present our recent acoustic microrobotic design which has a negative acoustic contrast factor, allowing them to be trapped at the focal spot of focused ultrasound waves under fast fluid flows. The stable trapping and manipulation of the acoustic microrobots will enable a wide range of targeted therapeutics and minimally invasive interventions in confined spaces of the body.