Fast Response Humidity Sensor

Web Published:

3/4/2014

Description:

Fast Response Humidity Sensor

Princeton Docket # 14-2947

Researchers in the Department of Mechanical and Aerospace Engineering at Princeton University have developed a fast response humidity sensor. Conventional humidity sensors rely on principles such as radiation absorption or capacitance of the air. This new sensor produces high frequency humidity measurements indirectly through high frequency thermal conductivity measurements. Accurate measurements of energy fluxes in the atmosphere can be made, since the thermal conductivity of air is a strong function of humidity. The device provides accurate results independent of air velocity.

This novel sensor employs a micro-electro-mechanical system (MEMS) device and is fabricated using standard nano-manufacturing techniques. Several etching steps are used to create a free-standing nanowire supported by electrically conducting supports. The nanowire is heated by an electrical current fed through it. Its small size makes conductive heat transfer dominate over convection eliminating sensitivity to velocity. The heat transferred from the wire can be related to the thermal properties of the air surrounding it.

Applications:

· E nergy flux sensors for climate and meteorological measurements

· Real-time humidity sensing

· Fast measurements of thermal conductivity of a fluid

Advantages:

Compared to conventional sensors,

this new sensor is:

· Faster, i.e., much broader bandwidth

· Insensitive to air velocity

· Smaller

· Considerably lower cost

Faculty Inventor

Marcus Hultmark is Assistant Professor of Mechanical and Aerospace Engineering at Princeton University. He received his Ph.D. from Princeton University in 2011 after receiving the Porter Ogden Jacobus Fellowship in 2010 – the highest honor awarded by the graduate school. His research interests include a variety of problems related to turbulent flows, with focus on transport phenomena, such as heat and mass transfer as well as drag reduction. An important part of his research program is development and evaluation of new sensing techniques to investigate these phenomena with high accuracy.

Intellectual Property Status

Patent protection is pending.

Princeton is seeking to identify appropriate partners for the further development and commercialization of this technology.

Contact

Michael R. Tyerech
Princeton University Office of Technology Licensing • (609) 258-6762• tyerech@princeton.edu

Laurie Bagley
Princeton University Office of Technology Licensing • (609) 258-5579• lbagley@princeton.edu