This study investigates the electronic transport properties of graphene nanoribbons (GNRs) and demonstrates that their energy band gap can be engineered through lithographic processes. The research focuses on GNRs with varying widths and crystallographic orientations, where the lateral confinement of charge carriers creates an energy gap near the charge neutrality point. The energy gap was measured using temperature-dependent conductance measurements in the non-linear response regime. The results show that the energy gap scales inversely with the ribbon width, indicating that the band gap of GNRs can be controlled by lithographic techniques. The study involved over two dozen GNRs of different widths and orientations, fabricated from single sheets of graphene extracted from bulk graphite. The GNRs were contacted with metal electrodes and patterned into ribbons of varying widths and lengths. The devices were measured at different temperatures, and the conductance was found to decrease with increasing gate voltage, indicating the presence of an energy gap. The energy gap was observed to be significantly larger in narrower GNRs, with the narrowest GNRs showing the greatest suppression of conductance. The energy gap was quantitatively analyzed by examining the differential conductance in the non-linear response regime. The results showed that the energy gap scales inversely with the width of the GNR, consistent with theoretical predictions. The study also found that the energy gap is not systematically dependent on the crystallographic orientation of the GNRs, suggesting that edge structure and edge orientation play a more significant role in determining the energy gap than the crystallographic direction. The findings demonstrate that the energy gap in GNRs can be tuned during fabrication by controlling the ribbon width, which is a crucial step toward the development of graphene-based electronic devices. The study also highlights the importance of understanding the edge structure and orientation in GNRs for future research in this area.This study investigates the electronic transport properties of graphene nanoribbons (GNRs) and demonstrates that their energy band gap can be engineered through lithographic processes. The research focuses on GNRs with varying widths and crystallographic orientations, where the lateral confinement of charge carriers creates an energy gap near the charge neutrality point. The energy gap was measured using temperature-dependent conductance measurements in the non-linear response regime. The results show that the energy gap scales inversely with the ribbon width, indicating that the band gap of GNRs can be controlled by lithographic techniques. The study involved over two dozen GNRs of different widths and orientations, fabricated from single sheets of graphene extracted from bulk graphite. The GNRs were contacted with metal electrodes and patterned into ribbons of varying widths and lengths. The devices were measured at different temperatures, and the conductance was found to decrease with increasing gate voltage, indicating the presence of an energy gap. The energy gap was observed to be significantly larger in narrower GNRs, with the narrowest GNRs showing the greatest suppression of conductance. The energy gap was quantitatively analyzed by examining the differential conductance in the non-linear response regime. The results showed that the energy gap scales inversely with the width of the GNR, consistent with theoretical predictions. The study also found that the energy gap is not systematically dependent on the crystallographic orientation of the GNRs, suggesting that edge structure and edge orientation play a more significant role in determining the energy gap than the crystallographic direction. The findings demonstrate that the energy gap in GNRs can be tuned during fabrication by controlling the ribbon width, which is a crucial step toward the development of graphene-based electronic devices. The study also highlights the importance of understanding the edge structure and orientation in GNRs for future research in this area.