Realizing mechanical non-reciprocity in soft composites through shear jamming

Mechanical non-reciprocity, where a material system exhibits asymmetric responses to external stimuli along different directions, has recently attracted significant attention in the field of mechanical meta-materials. Traditionally, static non-reciprocal materials are fabricated by designing topological nonlinearity into the mechanical systems. In this work, we report a new approach to achieve mechanical non-reciprocity in soft composites by incorporating a shear-jammed particle network within the soft matrix. By controlling the material parameters of the gel matrices and the structural configuration of the shear-jammed particles, we demonstrate how the degree of non-reciprocity can be quantitatively varied. The mechanical non-reciprocity is fundamentally related to a shear-jamming phase diagram of the included particles. Finally, the non-reciprocal composites are promising candidates for engineering soft actuators with asymmetric responses.