Selective Manipulation and Trapping of Magnetically Barcoded Materials

Abstract Manipulation of magnetic materials (including remote‐controlled motions or structural deformations) plays a major role in modern micro‐ to macro‐scale systems. Magnetic operations create highly predicable outcomes in the behavior of systems, however these have difficulty performing subordinate and/or higher‐order operations. This lack of selectivity remains a critical drawback of magnetic manipulation schemes. Here, a strategy of engineering highly selective magnetic responses is studied and implemented. This is achieved by combining magnetic barcodes (“keys” encoded with layers of magnetic anisotropy) with programmable magnetic platforms (locking select codes in place with matching spatiotemporal magnetic fields). Presently, barcodes are realized by encoding hydrogel with sequences of magnetic microchains with binary spatial orientations. A number of unique capabilities of this approach are studied, including the untethered, selective anchoring of magnetic barcodes to programmable sites, as well as the selective latching of barcodes against background magnetic tags during flow. This approach may be used as a building block in micro‐ to macro‐scale magnetic interfaces.