Multi-layered powder-in-hydrogel capsules by magnetism-assisted bubbling method

•Multi-layered powder-in-hydrogel capsules are produced by magnetism-assisted bubbling method.•Tailored topology is controlled by solution constitution and fabrication route.•The capsules allow temporal and spatial control by floating and magnetic field.•The capsules allow sequential release by ultrasonic exposure and topology control.•Direct encapsulation of water-insoluble powder without organic solvent is achieved.