Airflow field-based manipulation

In nature, airflow or wind can displace a variety of objects such as pollen, pathogens, droplets, plant seeds, and leaves over a great distance of many meters and beyond, maintaining the very ecosystem we are living in. Inspired by wind, we have developed a technique that can manipulate the objects’ motion trajectories using jet-induced airflow from up to several meters away from the air nozzle. We achieved such manipulation capability by steering the direction of the air nozzle based on the position and displacement of the objects we were manipulating. We designed a control algorithm to control the direction of the air nozzle with respect to the object position, such that the airflow will blow the object in the desired direction including towards the air nozzle, instead of just blowing them away.  This allows us to use the airflow to manipulate the motion along different trajectories, in circles, following complicated letter-like paths, etc. Our method is versatile with respect to the object shapes and materials, and we can manipulate a wide range of objects from regularly shaped polystyrene hemispheres and sticks to irregularly shaped cotton wads and face masks as well as deformable crumpled tissue papers and plastic bags along reference paths.

The non-contact manipulation is useful in applications where physical contact is challenging or impossible. We have demonstrated that besides path-following manipulation on solid surfaces, we can also manipulate objects on water surfaces (or amphibious) and in the presence of disturbing airflows. We have also performed automated tasks such as collecting objects into a target receptacle, manipulating a mobile tethered agent to hook and retrieve heavy objects, and maneuvering a tethered soft agent to close an electrical circuit.