Responsive friction modulation of 3D printed elastomeric bioinspired structures

Elastomeric bioinspired structures with desirable friction performances are attractive for engineering applications. However, friction-tuning mechanisms through hybrid designs and shape fabrication techniques remain challenging. Herein, we developed a scalable elastomeric bioinspired structure using 3D printing inspired by claws, toe pads and overhang granules found in nature. Friction modulations are demonstrated with pillar and dimple hybrid structures in dry and wet conditions, including different structure arrangements, mechanical properties (strength similar to 13.8 MPa, elongation similar to 410%) and numerical simulations. We identified pillar hybrid design has strong friction features (similar to 2.5 times higher than smooth) on wet surfaces, by evaluating through strong edge boundary and spontaneous liquid splitting effects. Pillar structures are used to mimic grip experiments and simulations to determine gripping strategies.