This NIRT proposal focuses on developing a novel carbon nanotube ionization chemical sensor for emergency rescue crews and first responders that will enable "on-site" monitoring. The proposed sensor is light-weight, compact, robust, affordable, consumes low power (battery operated) and can provide definitive identification of contaminants in real-time mode with fast response.
Intellectual Merit: Our idea for sensing takes advantage of the extremely high electric fields that are generated near nanotube tips as a means of inducing ionization and electrical breakdown of the gas at low voltages. By monitoring the breakdown voltage, the gas can be identified (every gas has a characteristic breakdown behavior) and by monitoring the discharge current, the gas concentration can be determined. In this project we will perform a series of experiments with individual nanotubes as well as ensembles of tubes (electrode arrays) to gain a fundamental understanding of the basic mechanisms for ionization and breakdown of gas species and mixtures near nanotube electrodes. The experiments will be supported by density functional theory predictions for gas ionization near sharp nanotube tips. Based on the understanding gained from this study we will assemble integrated devices to detect trace amounts of analytes in mixtures and we will quantify the sensitivity, selectivity and sensor power consumption.
Broader Impact: On-site chemical sensing is critical to environmental monitoring, control of chemical processes, space missions, agricultural and medical applications. Broader impact of sensing is also well recognized in light of homeland security issues. To integrate teaching and research we will introduce sensing experiments and multimedia virtual-labs into the curriculum. We will also connect to the outreach of the NSEC Center to introduce Nanotechnology to K-12 students and teachers.
