Ionic Liquid Thin Layer Sensor

Description of Technology

This invention employs ionic liquid (IL) films, which are non-volatile and capable of concentrating gases for subsequent detection. The invention includes multiple electrodes that can be modified with different IL compositions to enhance the selectivity of the sensor. In addition, simultaneous sensing can be carried out with two orthogonal methods to provide additional selectivity to the sensor and significantly increase the accuracy of the detection at little or no added power cost. This multi-dimensional sensing takes advantage of the unique properties of IL to realize both the electrolyte for electrochemical detection (e.g., amperometric) and the sorption material for piezoelectric quartz crystal microbalance detection, enabling a single gas sensor with enhanced sensitivity, specificity, and stability.

Key Benefits

• Greater measurement confidence: Increased selectivity reduces false positives (i.e., false alarm from gases that were not the target) and false negatives (i.e., no alarm when targeted gases are present).
• Longer shelf life: IL films have very low vapor pressures and do not degrade over time.
• Longer operational life: IL films are effectively inert under operational conditions and can be regenerated with high heat.
• More reliable in high temperature operation: Compared to IL-based sensors, conventional metal oxide sensors lose sensitivity at high temperatures because their resistance changes nonlinearly in the presence of organic vapors, CO, and hydrogen gas.

Applications

• Flammable gas sensors for ambient air monitoring, occupational health and safety, biomedical diagnostics, industrial process control, and military and civilian counter-terrorism.
• Hazardous gas sensors to detect methane gas for safety monitoring.
• Explosives detectors for sensing the vapor phase of TNT and dinitrotoluene (DNT) in ppm and ppb concentrations, respectively.
• Organic volatile sensors to detect organics on toys, clothing, carpet, paints, and so on.
• High temperature sensors for identifying emissions within exhaust gases in high-polluting vehicles.

Patent Status

Patent pending

Inventors

Yue Huang, Andrew Mason

Tech ID

TEC2009-0110