PFI-RP: Additive Manufacturing for Scalable Metalens Fabrication

The broader impact/commercial potential of this Partnerships for Innovation – Research Partnerships (PFI-RP) project is the design and fabrication of high performance metalenses using an innovative, cost-effective approach that will enable a superior product that cannot otherwise be manufactured in a scalable manner. Metalenses (or flat lenses) are ultrathin planar lenses that use nanofeatures patterned on the surface to efficiently control light. thereby eliminating the bulkiness of traditional glass and plastic lenses while providing more utility and function in a substantially lighter and smaller volume.

Lens miniaturization and the introduction of wide fields of view and corrections for distortion and color aberration, all possible with metalenses, have enormous economic potential for consumer products, medical, defense, and space applications. Technology insertion points include cell phone cameras, augmented reality / virtual reality (AR/VR), heads-up displays, medical and scientific imaging, precision optics, and high-resolution imaging satellites, with associated markets exceeding $100 billion.

The PFI RP team addresses the critical elements of the supply and technology chains enabling domestic commercialization of an emerging technology with substantial societal impact.

The proposed project is a novel but achievable additive manufacturing approach for all inorganic, titanium oxide metalenses that involves a variation of nanoimprint lithography using crystalline nanoparticle-based inks. By enabling direct “printing” of the lenses, the additive process stands. The proposed technology is in contrast to current multi-step subtractive fabrications of all-inorganic visible metalenses that are based on technologies and processes developed for the semiconductor industry.

The team’s unique materials and process developments enable rapid cycle times, tunable refractive index (up to 2.1), and high aspect ratio features for highly efficient, all-inorganic flat lenses. State-of-the-art and innovative lens design and simulation are applied to take advantage of these unique and flexible fabrication capabilities and deliver outstanding lens performance, as confirmed by prototype testing.

Key innovations in fabrication include developing stable nanoparticle inks, a unique pulsed UV light cure approach that provides intense but localized heating to rapidly stabilize the imprinted structures and remove organics without increasing bulk temperatures, and post-manufacturing treatments that further enhance the refractive index. While innovative, the process is scalable and will be demonstrated on full-scale manufacturing tools using commercially accepted solvents and process flows.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.