Cut-Enabled Mechanical Metamaterials for Multimodal and Reprogrammable Static Nonreciprocity.

Area of Science:

• Mechanical metamaterials
• Nonreciprocity physics

Background:

• Static nonreciprocity is crucial for mechanical logic and soft robots.
• Current metamaterials struggle to achieve multiple, reprogrammable nonreciprocal modes within one structure.

Purpose of the Study:

• To demonstrate a novel design for cellular metamaterials enabling multiple static nonreciprocal modes.
• To establish a framework for describing and programming these multi-modal nonreciprocal behaviors.

Main Methods:

• Introduced cuts within metacells to induce contact nonlinearity.
• Developed a constitutive tensor framework to characterize nonreciprocal behaviors.
• Enabled programmability by controlling the positions of internal cuts.

Main Results:

• Achieved orthogonal, uniaxial, and shear static nonreciprocal modes (including displacement and Poynting effect).
• Demonstrated programmable control over nonreciprocal responses through cut encoding.
• Successfully synthesized multiple nonreciprocal modes in a single microstructural topology.

Conclusions:

• This design method offers a pathway to create advanced metamaterials with enhanced functionalities.
• The programmable nature of the nonreciprocity expands possibilities for mechanical logic and soft robotics.
• The study advances the field of metamaterials by enabling multi-modal and controllable static nonreciprocity.