High-temperature superconductors such as YBa₂Cu₃O₇₋δ (YBCO) exhibit strongly anisotropic electronic properties, with their superconducting energy gap varying along different in-plane crystallographic directions. Understanding this anisotropy is key to unraveling the complex pairing mechanisms and symmetry-breaking phenomena that underlie high-Tc superconductivity. In this seminar, I will describe how I use focused helium ion beam (FHIB) technology to fabricate Josephson junctions with nanometer precision, enabling highly controlled, directional tunneling measurements along the a and b axes of YBCO. Our group applies FHIB-based junctions to systematically probe the in-plane anisotropy of the superconducting gap by comparing tunneling spectra collected along different crystallographic orientations. To connect these electronic measurements to the underlying material structure, I correlate the tunneling results with complementary materials characterization methods, including Photoemission Electron Microscopy (PEEM), X-ray Diffraction (XRD), and Transmission Electron Microscopy (TEM). These techniques reveal local strain fields, defects, and structural domains that influence the measured anisotropy. By integrating precise FHIB junction fabrication with advanced characterization, this work provides new insight into the directional properties of YBCO and demonstrates how nanoscale tunneling devices can be used to explore the fundamental physics of high-Tc superconductors.