Before revision:  We present results from two example systems, firstly a droplet filled with an active polar fluid with polar anchoring at the droplet interface. Secondly, an active isotropic fluid consisting of particles that can bind and unbind from the interface and generate surface tension gradients through active contractility  }  . These two systems demonstrate spontaneous symmetry breaking and steady state dynamics resembling cell motility and division and show complex feedback mechanisms with minimal degrees of freedom.
After revision:  We present results from two example systems, firstly an active isotropic fluid boundary consisting of particles that can bind and unbind from the interface and generate surface tension gradients through active contractility } . These two systems demonstrate spontaneous symmetry breaking and steady state dynamics resembling cell motility and division and show complex feedback mechanisms with minimal degrees of freedom.