Continuously tunable mechanical metamaterials based on gear cells

Mechanical metamaterials with tunable mechanical properties have received widespread attention. However, it is still challenging to develop multifunctional mechanical metamaterials with continuous steady-state tunability over a wide range. In this work, a micro-gear unit structure is proposed, which is periodically arranged in a twodimensional plane to form a metamaterial. The structural design principle and stability are analyzed. We show that this metamaterial can achieve continuous and stable adjustment of mechanical properties. Through finite element simulation, the study analyzes various mechanical properties of the metamaterial, including statics and dynamics. The results demonstrate that the Young's modulus of the external gear cells can be adjusted over 10 times, while the internal gear cells show an adjustment range of over 200 times. The shear modulus also exhibits significant adjustability. Additionally, this gear unit-based metamaterial allows for continuous changes in natural frequency and frequency amplitude curves, which presents new possibilities for vibration reduction material designs. Furthermore, the research presents multiple metamaterial structure designs based on this micro gear unit, showcasing its versatile application potential across various scenarios, offering broad prospects for practical applications.