Researchers in Finland blow things into order

According to professor Quan Zhou, while wind is an everyday occurrence, blowing around dirt, leaves, pollens and pathogens, manipulating it to move objects in a particular direction is far from straightforward.

“[With a leaf blower] we can’t control the direction the leaves move – we can only blow them together into a pile,” the Aalto University professor illustrated.

Zhou and his research team recorded thousands of movements in an artificially generated airflow to develop templates of how objects move on a surface in a jet of air. Their analysis revealed that although airflow patterns are generally chaotic, they are regular enough to move objects in different directions, including back toward the nozzle blowing out the air.

“We designed an algorithm that controls the direction of the air nozzle with two motors. The jet of air is blown onto the surface from several metres away and to the side of the object, so the generated airflow field moves the object in the desired direction,” he explained.

The algorithm, he told, is constantly adjusting the direction of the nozzle to ensure the airflow moves the objects along the desired trajectory, be it a circle or a more complex letter-like shape.

“Our method is versatile in terms of the object’s shape and material – we can control the movement of objects of almost any shape.”

While Zhou acknowledged that the technique must be refined further, he and his colleagues are optimistic about its real-life applications: It could be used to arrange items scattered on a surface, such as debris in waste collection points, or in complex processing tasks where physical contact is impossible, such as handling electrical circuits.

“We believe that this technique could get even better with a deeper understanding of the characteristics of the airflow field, which is what we’re working on next,” he stated.