Clinging-Microdroplet Patterning Upon High-Adhesion, Pillar-Structured Silicon Substrates

The rapidly increasing research interest in nanodevices, including nanoelectronics, nano-optoelectronics, and sensing, requires the development of surface-patterning techniques to obtain large-scale arrays of nanounits (mostly nanocrystals and/or nanoparticles) on a silicon substrate. Herein, we demonstrate a clinging-microdroplet method to fabricate patterning crystal arrays based on the employment of high-adhesion, superhydrophobic, pillar-structured silicon substrates. Different from the previous hydrophilic/ hydrophobic patterned self-assembly monolayer technique, this method provides a novel strategy to fabricate patterning crystal arrays upon pillar-structured silicon substrates of homogenous superhydrophobicity and high adhesion, which greatly simplifies the modification process of the supporting substrates. Ordered crystal arrays with a tunable size and distribution density were successfully generated, and individual crystals grew on the top of each micropillar. Besides soluble inorganic materials, protein microspheres and suspending Ag-nanoparticle or polystyrene-microsphere aggregations could also be patterned in regular arrays, showing the wide adaptation of such an adhesive patterning technique. This novel and low-cost technique for patterning crystal arrays upon silicon substrates could yield breakthroughs in areas ranging from nanodevices to nanoelectronics.