Integrated flow sensor for fluids with dynamic velocity, temperature and conductivity profiles

A new type of integrated thermal flow sensor containing two symmetrical measuring channels is presented. The structure permit optimisation of flow sensing in applications with transient velocity, temperature or conductivity profiles in the fluid and has improved sensitivities for small temperatures differences above ambient, necessary for medical applications. Analysis is made for fluid flow and heat transfer using analytical and FEA technics. Technological implementation optimises the compensation of the internal stresses in the suspended structures and passivation of the sensor structure for work in aggressive media. Electronic interfaces for processing are derived for development of a fully integrated variant of the sensor.