Milliscale Shape-Programmable Magnetic Machines Based on Modular Janus Disks

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