In nature, social insects are capable of self-organizing into various sophisticated and functional structures through local communications, which facilitate their cooperative accomplishment of complex tasks that are beyond the capabilities of individuals. Emulating this collective behavior in artificial robotic systems promises benefits in various engineering fields and has been partially realized through elaborate algorithm and physical designs. However, developing a swarm robotic system with group-level functionality at small scales remains a challenge. Herein, a microswarm system that mimics the structure and function of an ant bridge is realized by employing functionalized magnetite nanoparticles, which are paramagnetic and electrically conductive, as the building blocks. Through the application of a programmed oscillating magnetic field, the building blocks are reconfigured into a ribbon-like microswarm, which can perform reversible elongation with a high aspect ratio and, thus, is capable of constructing a conductive pathway for electrons between two disconnected electrodes with the bodies of functionalized nanoparticles. Furthermore, the microswarm is demonstrated to serve as a microswitch, repair broken microcircuits, and constitute flexible circuits, exhibiting a promising future for the practical applications in the electronics field.
Keywords: collective behaviors; colloids; magnetic microswarms; microelectronics; self-assembly; surface functionalization.