Development of Lightweight, Impact-Resistant Materials through Architecture and Interference Lithogr
Abstract
Hierarchically designed cellular materials have been used as a method to create mechanically robust engineered structures. Introduci, loading. PI Greer demonstrated nanolattices that simultaneously attain light weight, high strength/stiffness, recoverability, and m,ore recently impact resilience - by using a combination of architectural design and size effects that emerge in nanomaterials. The,se nanolattices represent a class of new, lightweight durable meta-materials that utilize optimized nanometer-sized induced materi,al properties and three-dimensional (3D) architectures, to enable distinct departure from existing material systems.Current Challeng,pact tolerance are desired, their scalable nanomanufacturing remains a difficult challenge, with enormous potential payoff. The stat,e-of-the-art two-photon lithography (TPL) is not amenable to scaling up because of the inherent voxel-by-voxel rastering of laser in,teraction volume within the polymer; even when enabled for a layer-by-layer production, this process will not attain manufacturable,speeds. (2) Dynamic Response. Architected materials enable novel combinations of properties: extremely light weight, exceptionally h,igh stiffness- and strength-to-density ratios, energy absorption, and flaw tolerance. Examples from Greers group include recoverabl,e hollow-tube and nano-labyrinthine non-periodic ceramic architectures, glassy carbon, and metals whose feature sizes span from nano,meters to microns, to macroscale. Mechanical properties of architected materials to date have mainly been explored in quasi-static r,egime, with virtually no work dedicated to exploring the dynamic response of micro-architected materials, i.e. impact. Exploiting ef,fects of material size and architecture in dynamic regime has potential to enable ultralightweight impact-resistant shields against,ballistic impact and blast loading. A key challenge i,paration-of-scales between unit cell and sample dimensions. This precludes proper impact testing because impact time scale allows el,astic waves to propagate from free boundaries back to the projectile. Another difficulty in dynamic testing of nanomaterials is the,lack of reliable methods to achieve consistent loading conditions while capturing proper temporal and length scales. Addressing thes,e issues represents key thrust of this proposal, where experimental and computational methods will be applied to obtain optimal mate,rial properties and architectures. We propose to develop advanced materials capable of ballistic impact absorption consistent with r,equirements outlined in DoD Test Methods for Ballistic Defeat Materials (MIL-STD-3038), as wellas a pathway to scale them up. Nanola,ttice fabrication will be accomplished using holographic patterns created by phase-polarization metasurface masks, advanced micro-fa,brication techniques, and custom photoresin development. The point of departure in this process is that a nanolattice sample with ma,croscale dimensions can be generated in a single exposure instead of resolving each individual feature sequentially. To manufacture,a specific nano-architecture, multiple beams can be generated using a single phase-polarization mask without concomitant increase in, the manufacturing complexity. Proposed work is based on unique expertise of PI Greer on developing new nano-architectd materials, a,nd co-PI Faraon in developing high performance optical phase masks for interference lithography. Gained knowledge promises to be ess,ential for the development and improvement of structural materials, resulting, for example, in reduced signature in Naval vessels. (
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 01, 2022
- Source ID
- N000142212384
Entities
People
- Julia R. Greer
Organizations
- California Institute of Technology
- Office of Naval Research
- United States Navy