Nanostructure-Textured Surfaces with Low Friction and High Deformation Resistance

Nanotextured surfaces can effectively reduce friction and adhesion, especially in applications with micro- and nanoscale contact interactions. However, for these surfaces, a common weakness is a lack of structural integrity of the individual nanotextures when subjected to contact loading, resulting in permanent deformation at even the moderate contact forces encountered in microscale systems. Nanostructure-textured surfaces (NSTSs), composed of arrays of novel Al/a-Si core–shell nanostructures (CSNs), have been developed with a desirable combination of low friction and high deformation resistance. When subjected to nanoscratch testing, these surfaces are shown to have extremely low coefficients of friction (as low as ～0.015), as well as no detectable nanostructure deformation at contact forces up to 8,000 μN (estimated contact pressure greater than 1 GPa). In addition, the NSTSs have low adhesion (pull-off) forces on the order of less than 1 μN. The unique properties of these NSTSs provide avenues for designing low-friction, deformation-resistant surfaces that could benefit a variety of fields, including micro/nanoelectromechanical systems (MEMS/NEMS), microelectronics, magnetic recording, or any other application where the mechanical integrity of nanostructures is important.