Sensirion AG is expanding its technology portfolio for liquid flow sensor applications. The microsensor specialist has announced a new level of miniaturisation for non-invasive liquid flow sensors based on planar microfluidic substrates. Innovative packaging enables Sensirion's highly sensitive thermal flow sensor microchips to measure non-invasively through the wall of a flow channel inside a microfluidic substrate (US Pat. 6813944). This design provides unique sensitivity for liquid flow measurement and bubble detection in the microlitre range.
A small digital CMOSens microchip (2.2 x 3.5 mm) is bonded to the microfluidic channel substrate. Beside the sensor element it houses the complete digital intelligence as well as the memory necessary for signal linearisation, temperature compensation and self-test algorithms. The sensor boasts a short flow sensing response time of around 30 ms, and sensor resolutions down to 0.5 nl/min are feasible.
Customised OEM applications based on this technology will be developed for high-volume applications.