Impact dynamics of suspension droplet on immiscible pool: A closed system study on impact Jamming

Impact of suspension droplet on liquid surfaces is important in many applications. The liquid surface provides a different stress distribution as the droplet penetrates compared to impact on solid surfaces, thus probing the suspension response in a transient and inhomogeneous stress condition. When the liquid in the pool is miscible with the suspension droplet, particle migration into the pool reduces the volume fraction, making the analysis challenging. Here, we investigate impact dynamics of cornstarch-in-water droplets on a silicone oil pool, the immiscibility of which ensures the droplet remains a closed system, allowing for probing the jamming transitions and relaxation without external particle loss. We have observed interesting dynamics what differ significantly from those observed with miscible pools and identified the controlling physics of the phenomena. Our findings enhance the common understanding of suspension behaviors under dynamic stress environments.