Milliscale Shape-Programmable\nMagnetic Machines Based\non Modular Janus Disks

Through billions of years of evolution, small and microorganisms\nhave come to possess distinctive shape-morphing abilities to live\nin complex fluid environments. However, fabricating milliscale programmable\nmachines with shape-morphing ability often involves complicated architectures\nrequiring arduous fabrication processes and multiple external stimuli.\nHere, milliscale programmable machines with reconfigurable structures\nand extensible sizes are proposed based on the sequential assembly\nof simple Janus disks at liquid surfaces. The modular machines consist\nof magnetic Janus disks that are assembled into expected chain shapes\nin turn. Based on the modular structures with programmable shapes,\nmultiple locomotion modes are developed according to their structural\ncharacteristics. Their multifunctionality in manipulating and delivering\nobjects through contacting or noncontacting ways based on the programmable\nstructures is demonstrated. The shape-programmable behaviors of the\nmachines open up a new way toward constructing reconfigurable soft\nmicrorobots and understanding complex assembly mechanisms.