Digital microfluidic biochip (DMFB) is a tiny device that can carry out a rich set of bioassays without the need of bulky equipment. However, designing a good general-purpose DMFB architecture is still considered a big challenge today. NP-hard synthesis problems make on-line synthesis virtually impossible on exiting array-based architectures. In this paper, we first elaborate on the major concerns in a DMFB design flow, from the aspects of both synthesis and physical design. We then propose a versatile ring-based architecture VERBA and its corresponding fast one-pass synthesis flow. Experimental results show that VERBA incorporated with the proposed synthesis flow is a better solution than existing architectures and synthesis algorithms especially for real-time cyber-physical systems.