Architected Lattices with Adaptive Energy Absorption

TL;DR

This paper introduces an innovative adaptive energy absorbing material using architected lattices filled with granular particles, enabling tunable stiffness and improved impact mitigation for protective applications.

Contribution

It presents a novel design of architected lattices with granular particles that actively control energy absorption and recoverability, surpassing passive solutions.

Findings

Tunable stiffness and yield strength by over an order of magnitude.

Reduced transmitted impact stress by up to 40%.

Demonstrated potential for diverse protective applications.

Abstract

Energy absorbing materials, like foams used in protective equipment, are able to undergo large deformations under low stresses, reducing the incoming stress wave below an injury or damage threshold. They are typically effective in absorbing energy through plastic deformation or fragmentation. However, existing solutions are passive, only effective against specific threats and they are usually damaged after use. Here, we overcome these limitations designing energy absorbing materials that use architected lattices filled with granular particles. We use architected lattices to take advantage of controlled bending and buckling of members to enhance energy absorption. We actively control the negative pressure level within the lattices, to tune the jamming phase transition of the granular particles, inducing controllable energy absorption and recoverable deformations. Our system shows tunable stiffness and yield strength by over an order of magnitude, and reduces the transmitted impact stress at different levels by up to 40% compared to the passive lattice. The demonstrated adaptive energy absorbing system sees wide potential applications from personal protective equipment, vehicle safety systems to aerospace structures.