Date of Defense
2-4-2026 1:30 PM
Location
Microsoft Teams
Document Type
Thesis Defense
Degree Name
Master of Science in Electrical Engineering (MSEE)
College
COE
Department
Electrical and Communication Engineering
First Advisor
Prof. Falah Awwad
Keywords
SWCNT-FET, hexanal, liver cancer, breath analysis, VOC sensor, NEGF, Extended Hückel, QuantumATK, metallic SWNT electrodes, transmission spectrum.
Abstract
There are still no tests to detect liver cancer in the early stages because it is a slow-growing and invasive type.
This study describes the use of a single-walled carbon nanotube-based field-effect transistor (SWCNT-FET) whose ability to detect hexanal, a volatile organic compound (VOC) found to be elevated in liver cancer, has been demonstrated through direct measurements from exhaled breath. The device is designed using QuantumATK with the semi-empirical Extended Hückel Hamiltonian framework in non-equilibrium Green’s function (NEGF) which shows realistic contact physics by using metallic SWCNT electrodes instead of common metal films. Through the analysis of two zigzag channels with (11,0) and (12,0) chiralities, we show how the geometry as well as the contact matching affects charge transport.
The simulations consist of the current–voltage (I–V) characteristics and the transmission spectra at gate bias varying from 0 to 2 V and the operating point focused on is 1.4 V. Similar conductance quench is observed upon hexanal adsorption and anti-resonance is seen at the Fermi level. Of all the geometries tested in the study, the (11,0) channel in combination with metallic SWCNT contacts shows the largest conductance change and clearest gate-tunable response. This discloses a stronger sensitivity or performance without degrading stability. An assessment of selectivity towards common breath VOCs (i.e. acetone, ethanol) is provided, along with a noise-aware method to estimate the limit of detection from simulated transfer curves. In summary, our results suggest that well-matched all-carbon contacts, in addition to biasing close to 1.4 V, can enhance the hexanal signature in SWCNT-FETs, which makes it possible to create a compact and non-invasive breath test for early diagnosis of liver cancer.
Included in
BREATH-BASED DETECTION OF LIVER CANCER BIOMARKERS USING AN SWCNT-FET NANOBIOSENSOR: QUANTUMATK
Microsoft Teams
There are still no tests to detect liver cancer in the early stages because it is a slow-growing and invasive type.
This study describes the use of a single-walled carbon nanotube-based field-effect transistor (SWCNT-FET) whose ability to detect hexanal, a volatile organic compound (VOC) found to be elevated in liver cancer, has been demonstrated through direct measurements from exhaled breath. The device is designed using QuantumATK with the semi-empirical Extended Hückel Hamiltonian framework in non-equilibrium Green’s function (NEGF) which shows realistic contact physics by using metallic SWCNT electrodes instead of common metal films. Through the analysis of two zigzag channels with (11,0) and (12,0) chiralities, we show how the geometry as well as the contact matching affects charge transport.
The simulations consist of the current–voltage (I–V) characteristics and the transmission spectra at gate bias varying from 0 to 2 V and the operating point focused on is 1.4 V. Similar conductance quench is observed upon hexanal adsorption and anti-resonance is seen at the Fermi level. Of all the geometries tested in the study, the (11,0) channel in combination with metallic SWCNT contacts shows the largest conductance change and clearest gate-tunable response. This discloses a stronger sensitivity or performance without degrading stability. An assessment of selectivity towards common breath VOCs (i.e. acetone, ethanol) is provided, along with a noise-aware method to estimate the limit of detection from simulated transfer curves. In summary, our results suggest that well-matched all-carbon contacts, in addition to biasing close to 1.4 V, can enhance the hexanal signature in SWCNT-FETs, which makes it possible to create a compact and non-invasive breath test for early diagnosis of liver cancer.