Optical Humidity Sensors for Indoor Air Quality Control

Period of Performance: 06/13/2016 - 03/12/2017


Phase 1 SBIR

Recipient Firm

Intelligent Optical Systems, Inc.
2520 W. 237th Street Array
Torrance, CA 90505
Firm POC
Principal Investigator


As novel building envelopes are implemented to reduce energy use, indoor air quality can be compromised. Humidity sensing must be part of any advanced indoor air quality system, but as stated in the DOE solicitation, "existing humidity sensors do not maintain accuracy over extended periods of time." Therefore, there is a need for a humidity sensing technology with long-term stability and costs competitive with current sensor products. Statement of how this problem is being addressed. Luminescence-based optical sensors for relative humidity are proposed, featuring unprecedented long-term stability, extremely high resistance to airborne contaminants, and no water retention, at a cost similar to those of commercially available sensors. Two key innovations will be combined: a passive material doped with a luminescent dye for enhanced stability, and implementation of a family of circuits that process analog signals on low-cost 100% digital components. What is to be done in Phase I? Phase I will focus on demonstrating the novel sensor material and in particular its superior stability in comparison with current humidity sensor devices, leaving the optimization of other parameters for Phase II. To evaluate long-term stability in the Phase I, we will conduct highly accelerated life testing studies. Demonstrating the "fabricability" of the novel material will be part of Phase I. Once the sensor material has been demonstrated, we will establish the basis for a low cost electronic circuit designed for the particular sensor material selected. Commercial applications and other benefits. Humidity measurement finds broad use in many industries. Humidity sensing is applied to process controls, food storage and refrigeration, quality control, homebuilding, heating, ventilation, and air conditioning (HVAC), medical, healthcare, automotive, and numerous other fields. Key words. energy, building, luminescent, optical sensor Summary for Members of Congress. As novel buildings are designed to reduce energy use, indoor air quality may be compromised but, as per the solicitation, "existing humidity sensors do not maintain accuracy over extended periods..." The proposed optical sensors for relative humidity will have unprecedented long-term stability at costs comparable to those of existing sensors.