Digital, Information-Encoded Magnetic Interactions for Addressable, Reconfigurable Micro-Assembly

Magnetic self-assembly of complex structures requires building blocks with highly programmable interactions. We use lithographically defined nanomagnetic domains as elemental interaction units and pattern them into digital, multi-bit magnetic “barcodes” on micrometer-scale building blocks. The information needed to guide addressable assembly from a set of tiles is encoded in these barcodes, so that only tiles with matching barcodes form strong, highly specific bonds, yielding near-perfect pairing accuracy in mixtures containing up to 20 distinct species. This level of control enables addressable formation of prescribed 1D and 2D micro-architectures. Furthermore, because the interparticle interactions are field-responsive and field-reconfigurable, time-varying magnetic protocols can correct errors, drive assemblies out of equilibrium, and even alter the interaction from bonds, paving the way toward truly programmable, responsive magnetic materials.