Dew point sensor using mems

A dew piont sensor comprising:

• a micro-cantilever beam formed on a sustrate;
• a cooling device in thermal contact with the micro-cantilever beam;
• and
• a control circuit coupled to the micro-device beam, the cooling device and the temperature sensor, wherein the control circuit is operable to monitor a resonance of the micro-cantilever beam, control a temperature of the cooling device and receive a temperature indication from the temperature sensor, thereby identifying the temperature of the micro-cantilever beam when the resonance of the micro-cantilever beam changes due to a change in mass caused by dew on the micro-cantilever beam when the dew point is reached;
• wherein the micro-cantilever beam vibrates at a frequency dictated by a voltage potential across the electrodes;
• the cooling device comprises a thermoelectric chiller and is integrated with the micro-cantilever beam on the substrate;
• and
• wherein the thermoelectric chiller is formed on the micro-cantilever beam, wherein the thermoelectric chiller comprises;
• an insulating layer formed on the micro-cantilever beam;
• and
• a plurality of thermoelectric structures formed of two types of material, and wherein alternating material type thermoelectric structures contact one another forming a cold junction adjacent a first end of the micro-cantilever beam and a hot junction adjacent a second end of the micro-cantilever beam at end.

A method of determining the dew point, comprising the steps of:

• exciting a micro-cantilever beam in a vibratory mode;
• decreasing a temperature of the micro-cantilever beam, wherein when the temperature reaches the dew point, dew forms on the micro-cantilever beam and changes the mass of the micro-cantilever beam which causes a resonance of the micro-cantilever beam to change;
• and
• monitoring the resonance of the micro-cantilever beam, wherein a change in the resonance determines the dew point.