“The authors have created a 3D printed microrobotic prototype capable of finding pollutants and kill bacteria. Ranging from micrometers to millimeters, the small machines can be fabricated affordably and quickly—with batch production easily achieved. Fabricated via SLA 3D printing, the microdevices were created with a magnetic layer (composed of silver) that allows for remote action due to a controlling magnetic field. The microdevices were also coated with a silver/titania composite: …”
For more:
https://3dprint.com/243402/swiss-italian-researchers-3d-print-microdevices-clean-water/