The MEMS sensor company Sensirion AG presents a 4th-generation CMOS-based microsensor chip for liquid drug flow monitoring in portable systems, implantables or disposable drug delivery solutions. The semiconductor chip opens up new product design opportunities for drug delivery systems. Very small amounts of liquid can now be monitored which allows to add supplementary electronic monitoring and control features to drug delivery systems.
The fully digital microchip is merging a flow sensor element with memory for calibration data as well as digital intelligence for linearization and temperature compensation on one single MEMS sensor chip (size 2 x 3.5 mm). The thermal sensor works fully non invasive, since the MEMS chip can be bonded on the outside of a capillary and sense through the wall of this channel (bonding not releasable, US Pat. 6813944). Such sensors enable bubble detection and accurate measurement of very low liquid flow rates down to micro- and nanoliters per minute with very short response times and outstanding repeatability. As the tiny chips are based on CMOS technology, they can easily be produced in high volumes at low cost in standard semiconductor wafer fabs.