A silicon micromachined alcoholometer

This research work was aimed at finding an innovative process based on MEMS technologies to measure the alcoholic strength of hydro-alcoholic solutions. A new Si micromachined alcoholometer was developed. A microhotplate, based on a dielectric thin membrane, is used to heat and measure the temperature of droplets of hydro-alcoholic solution dispensed by a tiny capillary during an evaporation cycle. It was found that the alcoholic strength is correlated with the integration of the temperature of the droplet over time during its evaporation. Opposed to the old measurement methods, this new procedure takes advantage of many properties of the hydro-alcoholic solutions such as: superficial tension, latent heat of evaporation, boiling point and heat capacity. All these issues contribute together to give a good response in terms of good resolution and accuracy over a wide range of alcoholic degree.