Swarmalators move as a function of their pairwise phase interactions, and control their phase as a function of their relative position or motion to other agents. This enables dual sync and swarm behaviors that mimic those exhibited by diverse natural and artificial swarms; these behaviors have almost entirely been explored only through computational simulations. Here, we realize through a 15-robot collective many of the predicted swarmalator behaviors when agents are chiral and non-chiral, when there is frequency coupling, and when the natural frequency distribution is homogeneous and heterogeneous. This work presents an experimental platform that can realize many theoretically predicted collective behaviors, it sheds light on the differences between the simulations and experiments, and it will serve in future studies to realize swarmalator and active matter collective behaviors.

Natural and robotic swarms often exhibit nonreciprocal interactions; agents do not exhibit equal and opposite forces on each other. By studying the effects of reciprocal and non-reciprocal interactions we are better able to design emergent behaviors in robot collectives composed of agents that exert attractive and repulsive forces on each other. Moreover, by controlling agent-specific coupling forces on-demand, we can enable a collective to exhibit desired behaviors previously not possible. We use a general form of the swarming oscillator, swarmalator, model to study reciprocal and non-reciprocal interactions among agents that affect each other’s motions over long and short distances, we use non-reciprocal coupling to elicit collective locomotion toward or away from target sites, and we use the control barrier function method to optimize the non-reciprocal interactions for a desired spatial formation. This work addresses the interests of the active matter, swarm robotics, and control barrier functions communities and demonstrates various collective behaviors with strong potential to be realized in macro- and micro- length scale robot swarms.

Popcorn kernels are a natural, edible, and inexpensive material that has the potential to rapidly expand with high force upon application of heat. Although this transition is irreversible, it carries potential for several robotic applications. Here, we examine relevant characteristics of three types of kernels including expansion ratio, transition temperature, popping force, compression strength, and biodegradability. We test the viability of popping by hot oil, hot air, microwaves, and direct contact with heated Nichrome wire. As kernels can change from regular to (larger) irregular shapes, we examine the change in inter-granular friction and propose their use as granular fluids in jamming actuators, without the need for a vacuum pump. Furthermore, as a proof-of-concept, we also demonstrate the use of popcorn-driven actuation in soft, compliant, and rigid-link grippers. Serving as a first introduction of popcorn into robotics, we hope this paper will inspire novel mechanisms for multi-functional designs.