Additive manufacturing has significantly advanced the field of prosthetics, allowing for the production of highly customized prosthetic components. Among these, the prosthetic socket plays a critical role in securely attaching the residual limb to the prosthesis. The interface pressure between the residual limb and the prosthetic socket considerably impacts user comfort and quality of life. This study explores the influence of liner material’s Poisson’s ratio on contact pressure distribution within transtibial prosthetic sockets using Finite Element Analysis (FEA). Auxetic metamaterials, characterized by a negative Poisson’s ratio, exhibit unique mechanical properties that enhance adaptability and comfort in prosthetic applications. By analyzing the pressure distribution for various Poisson’s ratio values, the study reveals that auxetic materials contribute to a more uniform pressure distribution, reducing peak stresses on the residual limb. The findings suggest that integrating auxetic materials into prosthetic socket design can significantly improve the comfort and performance of prosthetic users. Further research should investigate additional mechanical properties to optimize prosthetic liner materials. .