Kirigami-Inspired Three-Dimensional Metamaterials with Programmable Isotropic and Orthotropic Thermal Expansion

Area of Science:

• Materials Science
• Mechanical Engineering
• Nanotechnology

Background:

• Existing thermal expansion metamaterials have limited cell topologies and deformation ranges, especially in 3D.
• Achieving tunable negative, zero, or positive thermal expansion (NTE/ZTE/PTE) in 3D is challenging.

Purpose of the Study:

• To develop 3D isotropic and orthotropic mechanical metamaterials with programmable thermal expansion.
• To achieve NTE, PTE, and ZTE over an ultra-wide range using a novel kinematic design strategy.

Main Methods:

• Utilized one-degree-of-freedom kirigami polyhedrons with a kinematic design strategy.
• Incorporated bi-material strips for isotropic polyhedrons and varied geometric parameters for orthotropic designs.

Main Results:

• Designed and programmed metamaterials with coefficients of thermal expansion (CTEs) from -2354.3 to 3006.7 ppm/°C.
• Achieved isotropic ZTE metamaterials through homogeneous or hybrid tessellation.
• Developed orthotropic metamaterials with independently programmable thermal expansion in three orthogonal directions.

Conclusions:

• This study presents a novel pathway for creating advanced thermal expansion metamaterials.
• The developed metamaterials have potential applications in space optical systems, MEMS, and other fields requiring precise thermal management.