In biology, many RNA molecules act as sophisticated microscopic machines. Among them, riboswitches function as tiny biological sensors, changing their 3D shape upon binding to a specific metabolite. This shape-change acts as a switch, often turning a downstream gene "on" or "off." The ability to design artificial switches from scratch would hold immense promise for synthetic biology, drug design, and new diagnostic tools. However, designing a sequence that can stably fold into two different shapes and switch between them is an extremely difficult challenge.