Nano gas sensors paper

High performance nanostructured Zinc Oxide Gas Sensor

Paper Outline

· Introduction: give introduction about Nano ZnO gas sensors.

· Motivation: Solid-state chemical sensors are gaining popularity and finding extensive use in process control, environmental monitoring and residential safety. ZnO, a semiconducting metal oxide has attracted great interest over the years for its sensitivity to a variety of gases. Nanostructured sensing materials, such as nanowires, nanotubes and quantum dots offer an inherently high surface area, thus reducing operating temperatures and increasing sensitivity to low concentrations of analytes.

· Gas sensor mechanism.

· Sensor Characteristics:

a. Sensitivity

b. Selectivity

c. Stability and Drift

d. Repeatability

e. Reproducibility

f. Response Time

· Influence of contact electrodes on sensor performance

a) Contact resistance plays an important role as dominant factor in overall resistance

b) Electrodes are generally made of high conductivity metals (Au, Pt,etc) by sputtering or e-beam evaporation

· Example of an existing ZnO gas sensor (source #1)

· Goal: To achieve flexible gas sensor with improved operating parameters such as sensitivity, selectivity, and reliability for wider applications

· Why flexible gas sensors: (talk about flexible gas sensors)

· Cost-effective device fabrication,

· Lighter weight

· Flexibility, and stretch ability to enable smart wearable, handheld and portable gas sensors

· Low production cost

· Possible applications:

· Environmental monitoring:

· Air quality control

· Chemical process control

· Car exhausts

· Alcohol detection: Car won’t start when detecting high level of alcohol

· Personal safety protection:

· Coal mines and plants workers

· Pipes leaking

· Approach to achieve goal

· Flexible substrates, polymers including polyimide PI introduced because of its extraordinary thermal, mechanical, and chemical properties

· Laterally grown NW arrays might simplify the process by eliminating the tedious NW assembly or registration steps, but it lacks reliability and control. Vertically aligned Nano rods (NRs) are more reliable and controllable.

Sources:

https://www.ukessays.com/essays/mathematics/gas-sensors-on-zinc-oxide-nanostructures.php