Our High-Resolution Shack-Hartmann Sensor, leveraging the nanostructured GRIN lens technology, sets a new standard for wavefront distortion measurement. This sensor utilizes a hexagonal array of hundreds of GRIN microlenses, each of tens of µm in diameter, to provide unparalleled precision in detecting and analyzing wavefront distortions. This novel approach results in a completely flat element, seamlessly integrating with other optical components and excelling in high refractive index mediums such as liquids. Ideal for applications in adaptive optics, lithography, and medical imaging, this sensor offers a robust solution for real-time wavefront correction and high-resolution imaging. Manufactured using advanced fabrication techniques to ensure uniformity and accuracy in lens dimensions and optical properties.