Direct Writing of Silver Nanowire Patterns with Line Width down to 50 mu m and Ultrahigh Conductivity

Direct writing of one-dimensional nanomaterials with large aspect ratios into customized, highly conductive, and high-resolution patterns is a challenging task. In this work, thin silver nanowires (AgNWs) with a length-to-diameter ratio of 730 are employed as a representative example to demonstrate a potent direct ink writing (DIW) strategy, in which aqueous inks using a natural polymer, sodium alginate, as the thickening agent can be easily patterned with arbitrary geometries and controllable structural features on a variety of planar substrates. With the aid of a quick spray-and-dry postprinting treatment at room temperature, the electrical conductivity and substrate adhesion of the written AgNWs-patterns improve simultaneously. This simple, environment benign, and low-temperature DIW strategy is effective for depositing AgNWs into patterns that are high-resolution (with line width down to 50 mu m), highly conductive (up to 1.26 x 10(5) S/cm), and mechanically robust and have a large alignment order of NWs, regardless of the substrate's hardness, smoothness, and hydrophilicity. Soft electroadhesion grippers utilizing as-manufactured interdigitated AgNWs-electrodes exhibit an increased shear adhesion force of up to 15.5 kPa at a driving voltage of 3 kV, indicating the strategy is very promising for the decentralized and customized manufacturing of soft electrodes for future soft electronics and robotics.

Automated summary

This work presents a direct ink writing (DIW) strategy using silver nanowires (AgNWs) as an example, in which aqueous inks with sodium alginate as the thickening agent can be easily patterned onto different planar substrates. With a quick postprinting treatment, the electrical conductivity and substrate adhesion of the AgNWs-patterns can be improved simultaneously. This simple, environmentally friendly, and low-temperature DIW strategy allows for the high-resolution, highly conductive, and mechanically robust deposition of AgNWs into customized patterns.