A brand-new engineering approach to generate "designer" biological robots using human lung cells is underway in Carnegie Mellon University's Ren lab. Referred to as AggreBots, these microscale living robots may one day be able to traverse through the body's complex environments to deliver desired therapeutic or mechanical interventions, once greater control is achieved over their motility patterns. In new research published in Science Advances, the group provides a novel tissue engineering platform capable of achieving customizable motility in AggreBots by actively controlling their structural parameters.