New flow control systems in capillarics: off valves

Abstract

Capillary systems are a promising technology for point-of-care microfluidics, since they are pre-programmable and self-powered. This work introduces "off valves" as a key building block for capillaric circuits, providing easy-to-use, multi-purpose valving functionality and autonomous flow control. To this end we present a set of switching valve designs that use trigger channels and liquid input alone to close or open connections between channels in a highly controllable fashion. The key element of all these valve designs is a new off trigger valve, which is characterised in detail here and holds the potential for transistor-like switching and resistance tuning. As an example for the potentia..