3D Printed Miniaturized Soft Microswimmer for Multimodal 3D Air-Liquid Navigation and Manipulation

Major challenges of microscale swimmers for biomedical applications could be listed as the 3D motion for air-liquid navigation, selective motion control of multiple swimmers, visual servo automation control and micromanipulation functionality. Here we report a miniaturized soft microswimmer for serving as a wireless microrobotic manipulator in air-liquid environments. We fabricated these micrometric soft swimmers by two-photon 3D nanoprinting of Polydimethylsiloxane (PDMS) and metallization of ferromagnetic nickel layer for magnetic propulsion. We demonstrated for the first time 3D air-liquid navigation and selective motion control of multiple soft swimmers thanks to the multimodal propulsion with magnetic and buoyancy force. We further reduced stick-slip phenomenon by applying high frequency vibration by piezo disc actuator. This allowed real-time visual tracking of the soft microswimmers and also the micromanipulation of microfibers. We believe that this 3D printed and miniaturized mobile agents should enlarge the application areas from in-vitro microfluidics to bio/chemical assay.