Non-Technical Abstract Active matter—systems composed of self-propelled particles such as bacteria or synthetic microswimmers—can behave in surprising ways when confined. For example, particles that move randomly in open space may exhibit organized, collective motion when enclosed. This project explores what happens when active particles are confined within a soft, flexible boundary like a droplet. The research team recently discovered that this setup leads to unexpected behaviors: the droplet itself spontaneously moves and deforms, driven by the activity inside. By combining theoretical modeling with controlled experiments, the investigators aim to uncover how particle motion and boundary softness interact to produce complex dynamics. Insights from this work could inform new approaches for microscale transport and control, with potential applications in soft robotics, environmental sensing, and targeted drug delivery. The project also supports interdisciplinary student training and public outreach through visually compelling experiments that mimic living systems, contributing to the growth of the STEM workforce and furthering NSF’s mission to advance scientific innovation. The project is committed to creating opportunities that are accessible to all Americans, without preference or exclusion of any individual or group. Technical Abstract This project investigates the collective dynamics of active colloidal particles confined within soft, deformable boundaries. While