Liquid Crystal Based Sensors for Environmental Monitoring of Toxic Gases
Poster Presentation
Prepared by S. Robinson, B. Grinwald, R. Bemowski, D. Pirsch, T. Burland
Platypus Technologies, 5520 Nobel Dr. , Suit 100, Madison, WI, 53711, United States
Contact Information: [email protected]; 608-237-1270
ABSTRACT
Liquid Crystal Based Sensors for Environmental Monitoring of Toxic Gases
Poster Presentation
Prepared by S. Robinson, B. Grinwald, R. Bemowski, D. Pirsch, T. Burland
Platypus Technologies, 5520 Nobel Drive, Suite 100, Madison, WI 53711
Contact Information: [email protected]; 608-237-1270
ABSTRACT
The same liquid crystals (LCs) used in TV and computer screens can also be used for gas sensing. LC films provide a much simpler means to readout chemical interactions than instrumentation. A gas sensor is made by spreading a thin film of LC over a chemically functionalized surface. The detection chemistry aligns the LC molecules in one orientation before exposure to the target, and after interaction with the target it aligns the LC molecules in a different orientation. The change in LC orientation appears as a change in brightness when viewed through crossed polarizers. The response requires no power.
This technology has been used to make a dosimeter that measures hydrogen sulfide (H2S) exposure during a work shift. The direct read dosimeter detects levels below electrochemical sensors and provides results on par with lab analysis without the expense. Further development of LC sensors is in progress for nitrogen dioxide (NO2), ammonia (NH3), and hydrogen sulfide (H2S) with recent advances in stability and sensitivity. This paves the way for creating simple, highly sensitive, low cost gas sensors for environmental monitoring, citizen science, and safety applications.
Poster Presentation
Prepared by S. Robinson, B. Grinwald, R. Bemowski, D. Pirsch, T. Burland
Platypus Technologies, 5520 Nobel Dr. , Suit 100, Madison, WI, 53711, United States
Contact Information: [email protected]; 608-237-1270
ABSTRACT
Liquid Crystal Based Sensors for Environmental Monitoring of Toxic Gases
Poster Presentation
Prepared by S. Robinson, B. Grinwald, R. Bemowski, D. Pirsch, T. Burland
Platypus Technologies, 5520 Nobel Drive, Suite 100, Madison, WI 53711
Contact Information: [email protected]; 608-237-1270
ABSTRACT
The same liquid crystals (LCs) used in TV and computer screens can also be used for gas sensing. LC films provide a much simpler means to readout chemical interactions than instrumentation. A gas sensor is made by spreading a thin film of LC over a chemically functionalized surface. The detection chemistry aligns the LC molecules in one orientation before exposure to the target, and after interaction with the target it aligns the LC molecules in a different orientation. The change in LC orientation appears as a change in brightness when viewed through crossed polarizers. The response requires no power.
This technology has been used to make a dosimeter that measures hydrogen sulfide (H2S) exposure during a work shift. The direct read dosimeter detects levels below electrochemical sensors and provides results on par with lab analysis without the expense. Further development of LC sensors is in progress for nitrogen dioxide (NO2), ammonia (NH3), and hydrogen sulfide (H2S) with recent advances in stability and sensitivity. This paves the way for creating simple, highly sensitive, low cost gas sensors for environmental monitoring, citizen science, and safety applications.
