A low-cost biocompatible mass flow sensor has great potential in biomedical diagnostics and research, where a large variety of fluids and samples are used. With conventional flow sensors, expensive and time consuming cleaning procedures are used, which can be eliminated by using a low-cost disposable sensor. Furthermore, a Coriolis type mass flow sensor would also eliminate the need for recalibration of the setup for each sample or the use of conversion factors for each medium as is required with e.g. thermal mass flow sensors. By using a low-cost disposable sensor cartridge with the sensor chip and fluid connectors and a separate electronics package, the costs of measuring can be low.
The sensor is fabricated using a polymer to find a compromise between costs and accuracy. Due to limitations of the fabrication and the material, this will result in a mass flow sensor that is less sensitive than a micro Coriolis mass flow sensor made in silicon micromaching technology. However, using a polymer fabrication process enables low-cost high-volume fabrication while the advantages of a Coriolis-type mass flow sensor remain. The sensor is intended for a flow range up to 50g/h with an accuracy in the order of 1% full scale. Initial results, using laser Doppler vibrometry for read-out and a syringe pump to apply the flow show a high linearity in this range.
This demonstrator project will focus on integrating read-out structures and developing a low-cost sensor cartridge and a separate electronics package containing the actuation and read-out electronics and electronics for interfacing to a computer. We are currently exploring potentially interesting applications. Examples are medical multi-infusion systems, biomedical diagnostics and (bio)chemical research.
Figure 1: SU-8 based microfluidic Coriolis mass flow sensor chip [1].
REFERENCES
[1] R. Monge, J. Groenesteijn, D. Alveringh, R.J. Wiegerink, J. Lötters, L.J. Fernandez, SU–8 micro coriolis mass flow sensor, Sensors and Actuators B: Chemical, Volume 241, 31 March 2017, pp. 744-749. pdf