Microrobot collectives with reconfigurable morphologies, behaviors, and functions

Abstract

Mobile microrobots, which can navigate, sense, and interact with their environment, could potentially revolutionize biomedicine and environmental remediation. Many self-organizing microrobotic collectives have been developed to overcome inherent limits in actuation, sensing, and manipulation of individual microrobots; however, reconfigurable collectives with robust transitions between behaviors are rare. Such systems that perform multiple functions are advantageous to operate in complex environments. Here, we present a versatile microrobotic collective system capable of on-demand reconfiguration to adapt to and utilize their environments to perform various functions at the air–water interface. Our system exhibits diverse modes ranging from isotropic to anisotrpic behaviors and transitions between a globally driven and a novel self-propelling behavior. We show the transition between different modes in experiments and simulations, and demonstrate various functions, using the reconfigurability of our system to navigate, explore, and interact with the environment. Such versatile microrobot collectives with globally driven and self-propelled behaviors have great potential in future medical and environmental applications.

Scale-reconfigurable miniature ferrofluidic robots for negotiating sharply variable spaces

“…The micro-FR swarm can be switched between the matrix pattern and vortex pattern by adjusting the SPM's rotating axis (z axis or any axis on the horizontal plane). As proved by previous works (48,49), realizing swarm control not only can retain the flexible characteristics of the small-scale robots due to their small size but also greatly improves their control efficiency and movement speed, which enables them to cross complex environments, such as a narrow channel and an undulating surface more efficiently.…”

Multicomponent and multifunctional integrated miniature soft robots

“…In addition, miniature soft robotic systems with loosely coupled interactions, such as selfassembly based on capillary force, dielectrophoretic forces or weak magnetic interactions, promise benefits in the high reconfigurability of morphology, behavior, and function of robotic systems. [197][198][199][200] Finally, the introduction of computational intelligence into the control strategies of a soft robotic system for autonomous adaption of each unit or their locomotion modes to the changing of an operation environment enables an appropriate decision-making ability for unknown and unstructured environments. 201,202…”

Emergent Microrobotic Oscillators via Asymmetry-Induced Order

“…1e, t = 3.2s). The collapse imparts an impulse onto the microparticles and propels them in opposite directions, at which point the particles are drawn back towards one another by the restorational forces: First, the radial component of buoyancy, F g , globally directs the particles towards the apex of the concave air-liquid interface [35]. Second, the local interfacial deformations result in a mutual attractive capillary force F c , affectionately known as the "Cheerios effect" [54,55].…”

“…The slow rate of these oscillations stems from a need to be commensurate with both the energy budget and the natural timescales of underlying biological processes, as in the transport of CO 2 in plants [30] and the flaps of insect wings [31]. Unlike oscillations arising from external periodic forcing [32][33][34][35], these self-oscillations emerge spontaneously from the balancing of competing dynamical processes driving systems away from equilibrium [21,36,37]-a signature of living systems [38]. In artificial microsystems, however, the production of slow selfsufficient self-oscillations is counterintuitively difficult [22,39].…”