Conformal metamaterial inspired contact lenses−designing, 3d printing and characterization for ocular applications

3D printed contact lenses have emerged as promising candidates for advanced ocular applications due to their customizable design and functional versatility.In this study, a novel conformal auxetic-inspired metamaterial ocular disc architecture was developed using digital light processing (DLP), a high-resolution vat photopolymerization technique, and fabricated using an in-house hydrogel formulation.The printed disc was systematically evaluated for its mechanical, optical, and physicochemical performance.Mechanical testing confirmed excellent elasticity and durability, with the hydrated hydrogel exhibiting a tensile modulus of ~0.71 MPa, matching the range of commercial soft contact lenses.Laser profilometry revealed a smooth surface topology essential for user comfort, achieving a root mean square roughness (Rq) of 1.78 µm, a nearly 98 % reduction compared to conventionally printed hemispherical lenses.Contact angle measurements (64° hydrated) indicated favorable wettability.Optical characterization exhibited high light transmittance, averaging ~83 % across the visible spectrum in the hydrated state.Hydration related properties, including swelling kinetics, water content, and gel fraction, confirmed effective water uptake and retention, supporting oxygen permeability.FTIR spectroscopy validated the chemical integrity of the polymer network, while DSC/TGA analysis confirmed thermal stability up to 300 ° C. Furthermore, rheological evaluation indicated a stable viscoelastic profile with notable self-healing behavior.Collectively, this study establishes a 3D printed hydrogel-based conformal metamaterial contact lens platform, offering a promising pathway for the development of next-generation smart ocular devices via additive manufacturing.