Integrated Micro-Liquid Dosing System

An integrated micro-liquid dosing system consisting of a micro-pump and a micro-liquid flow sensor is demonstrated. The dosing system allows accurate dosing of liquid in the p1 regime and can easily be integrated with components as mixers and detectors to micro-liquid handling systems [ 11. The liquid pump is of the reciprocating type with a thermo-pneumatic actuator. The micro-liquid flow sensor is based on the thermal anemometer type. Both pump and flow-sensor are realised in a 3-inch (100)- Si wafer using a KOH bulk etch from both sides of the wafer. Due to its small heat capacity, the flow sensor has a small time constant, making it suitable for the function of measuring the liquid flow. The effective liquid dose is in the pl/min range and a compatible fabrication process suitable for integration on a single wafer