Georgia Tech inventors have developed methods for the fabrication of gas sensors for a wide variety of gases using porous silicon in which the modification of nanostructured materials can be made to interact in a controlled manner to promote a distinct and controllable, wide ranging and variable interface sensitivity. These methods include methods of selecting a specific nanostructured deposit for a conductometric gas sensor, methods of detecting a gas based on the acidic or basic characteristic of the gas using a conductometric gas sensor, devices including conductometric gas sensors, arrays of conductometric gas sensors, and methods of determining the acidic or basic characteristic of a gas.
- Conductometric PS sensors, made with these methods have a rapid and reversible response to analyte gases at room temperature
- Sensors made with these methods have notably higher sensitivities and selectivity based on impedance changes
- Operate at room temperature as well in highly elevated temperatures when used in a heat-sink configuration
- Easy to coat with a variety of gas-selective materials to form sensor arrays for different gases
- Environmental gas sensors
Despite the vast number of chemical sensors on the market, there still remains a substantial need to develop new materials that sense gases in a broad range of environments. In recent decades, the need for gas sensing has increased due to widespread applications in homeland security, environmental monitoring, industrial emission control, and food quality control. In recent times, porous silicon (PS) has drawn considerable attention for sensor applications. Porous Silicon (PS) covers a broad range of chemically etched, electrochemically etched, or micro-machined materials. All of these materials can be made on a silicon wafer for the specific purpose of creating a region with a large surface to volume ratio. For this reason, Porous Silicon is being utilized as a sensitive layer to fabricate many kinds of sensors.