Figure 3.

Swimming mobility characterization of the printed PETA helical microswimmers with embedded FePt nanoparticles. A) Concept illustration of a PETA microswimmer with embedded FePt nanoparticles showing the velocity vectors of the microswimmers with forward and rolling velocity components. B,C) Swimming performance of the 30 μm long FePt/PETA and SPION/PETA magnetic helices with speeds as a function of the rotating magnetic field frequency at a given magnetic field magnitude. B) 5 mg mL¹ loading of FePt is compared with 5 mg mL¹ loading of SPIONs. A performance increase of approximately a factor of fivefold increase is achieved. C) Speeds of 180 μm s¹, six body lengths per second, are achieved at a step out frequency of 200 Hz for a 10 mT rotating field, higher than a 100 nm thick Ni-coated helical swimmer. D) Example trajectory of a microswimmer actuated by a rotating magnetic field with a 10 mT magnitude and 50 Hz frequency. Scale bar is 50 μm.