Flow sensor is offered for measuring nano liter and micro liter liquid flow rates for the medical, life science, and diagnostic industries. Typical applications include drug delivery, liquid handling, analytical instrumentation, lab-on-a-chip, molecular diagnostics, and flow cytometry. This high-performance sensor enables continuous feedback control, a critical requirement for many of these applications. The liquid flow sensor uses proprietary MEMS-based thermal anemometry technology to directly measure the mass-flow rate of liquids in an isolated flow channel. The primary features of this sensor are ultra-fast response time, high accuracy, low drift, high sensitivity, wide dynamic range, automatic temperature and viscosity compensation, small package size, and analog signal output.