Incredibly Small Liquid Flow Sensors

Swiss sensor manufacturer Sensirion AG has announced the launch of the new liquid flow series LPP10 and LPG10 in an unsurpassed small size. The new technology is based on planar microfluidic substrates and the sensors are available with a glass (LPG10) or a plastic (LPP10) packaging. Both versions have a footprint of a mere 10 x 10 mm. The glass version is extremely durable, while the plastic version is more suitable for disposable applications and is very cost-effective in high volume. Both versions are ideal for various medical and biomedical applications. The sensors have no moving parts and no obstacles in the flow path of the fluid.

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 planar substrate. This design provides unique sensitivity for liquid flow measurement and bubble detection in the range of 0 to 1000 microlitres per minute. The sensors are particularly suitable for monitoring flow rates and improving system performances in biomedical and life science applications.

Non-invasive flow sensing is possible thanks to the high sensitivity achieved with CMOSens^® Technology. A small digital CMOSens^® microchip (2.2 x 3.5 mm) is bonded to the microfluidic channel substrate. In addition to the sensor element, it houses the complete digital intelligence and the memory necessary for signal linearisation, temperature compensation and self-test algorithms. The chip provides a fully digital I²C interface. Electrical contact is made via metallisation above the microfluidic substrate. Fluidic ports below facilitate easy integration of discrete sensors into numerous designs. The sensor boasts a short flow sensing response time of 30 ms, and sensor resolutions down to 0.5 nl/min are feasible. A digital microsensor chip provides a fully calibrated digital output, eliminating the need for additional signal conditioning.

This significant simplification of liquid flow sensing technology enables extremely small and efficient sensor solutions. Customised solutions based on this technology can also be developed for various applications; standard versions are available immediately.