Lightweight Impact-Resistant and Flame-Retardant Materials: Lessons from Biology

As submitted by the proposer: Body armors are thick, rigid, heavy, and cumbersome for regular use, necessitating the research and development of lightweight, thin and flexible materials that offer protection from high-velocity projectiles and overheating.

The challenge with designing bullet-proof vests that meet NIJ Body Armor Standards is to develop structures that combine strength, toughness, fracture-resistance, and thermal protection, while considering comfort and ergonomics. The researcher proposes to design and fabricate materials for wearable next generation composite vests that offer enhanced impact and thermal protection. This will be done by understanding and mimicking millions of years of evolutionary traits within the structure of a mechanically and thermally robust follicle and seed-separator shielding system of the genus Banksia – a plant that has evolved to use forest-fires for seed dispersal.

Banksia follicles, with their encapsulated seeds, can survive forest-fires (producing 600°C temperatures) with no perceived damage to their structure and/or functionality. They also resist predation from pecking and abrading organisms. The hypothesis is that their multiscale structuring as well as site-specific gradation in the orientation, phase, and crystallinity of their material components enable the follicles to be impact resistant and thermally protective.

To test th hypothesis, the researcher will begin with a detailed ultrastructural investigation of the Banksia follicle and seed-separator shield system and (i) identify the microstructural and nanostructural features using microscopy and spectroscopy, (ii) measure mechanical (tension, compression, three-point bend, impact testing) and thermal (hot plane transient tests and phonon transport investigations) property gradients within the system, and (iii) mimic the structural ordering using advanced engineering materials to produce ballistic and temperature-resistant systems for the design of next-generation body armor.

The lab at UCR has state-of-the-art composite making facilities where the researcher intends to fabricate macro- and nanoscale composites with commercially obtained fire-resistant fibers and in-house electro-spun unidirectional nanofiber mats as reinforcements in heat-resistant matrices with varying fiber orientation angles mimicking the structural ordering of the Banksia follicle-seed separator system, and test them for strength, toughness, impact and thermal protection. It is expected to correlate and optimize mechanical and thermal test parameters between biological and artificial composite prototypes until satisfactory values are obtained validating the analysis.

In addition to providing NIJ with a truly multifunctional bio-inspired composite material capable of impact and thermal protection, the researcher also aims to deliver my official doctoral dissertation, quarterly reports, archived data sets compliant with NIJ’s data archival policies, and scholarly products such as peer-reviewed journal publications and conference proceedings, for the duration of the award.

This project contains a research and/or development component, as defined in the applicable law, and complies with Part 200 Uniform Requirements – 2 CFR 200.210(a) (14). nca/ncf

The applicant proposes to develop an advanced ballistic material for police body armor based on the materials of the seeds and related structures of the Banksia, a genus of Australian wildflowers that has evolved to resist fire as well as impacts associated with pecking and abrading organisms.

"Note: This project contains a research and/or development component, as defined in applicable law," and complies with Part 200 Uniform Requirements - 2 CFR 200.210(a)(14).

NCA/NCF