Single-use flow sensor based on the differential pressure principle employing the radial expansion of a low-cost silicone tube

For the first time, we present a flow sensor based on the differential pressure principle consisting of exchangeable low-cost consumable parts, to minimize the risk of cross-contamination in medical applications, for example. In our case, the consumable component consists of two thin-walled elastic silicone tubes connected by a rigid capillary that can be exchanged easily and costeffectively after use. We characterized the current flow sensor prototype in the range from 0 up to 50 μL/s for water and aqueous glycerin solutions with glycerol concentrations of 20 wt.-% and 60 wt.-% with known viscosities. The sensor showed a good consistency with the reference sensor, a linear correlation coefficient of minimal R(x,y) = 0.98 and a sensor resolution of 0.4 μL/s.