A microsensor for flow and diffusivity based on a completely new principle hasbeen invented under MAST project CT950029 "Micromare". It is based on the diffusive loss of a tracer from a reservoir through a membrane-filled pore. The tip of a transducer specific for the tracer is situated near the outer side of the membrane where it detects concentration changes. As the concentration gradient through the membrane is dependent on both the diffusive properties of the tracer in the membrane and advective transport or diffusive properties of the tracer in the external medium, the reading from the microsensor represents flow or, in stagnant media, diffusivity. The new microsensor is small (down to 10 m tip diameter), inexpensive, has a low energy requirement and can quantify flows over 4 orders of magnitude plus diffusivity in stagnant media. We will optimise this new sensor by choosing the best suited tracer and by optimising the detection of this tracer by the built-in transducer.
As the signal from the new sensor will be dependent on temperature, means of optical or thermocouple temperature compensation will be investigated and implemented. The new sensor with built-in temperature compensation will be used on a benthic lander in both shallow waters and in the deep sea. For deep sea use, a pressure stable (600 bar) sensor filled with liquid will be developed. The new sensor will be protected by patents and the feasibilily of commercial production and marketing will be investigated. The potential use of the new sensor in fields like medicine, physiological research, and micro-mechanics will also be investigated.
Funding SchemeDEM - Demonstration contracts