Nanoscale self-assembly is a concept that Nature has been making use of since the beginning of life, [1] and we have only recently started realizing its potential for achieving better control over materials properties. An overwhelming number of self-assembly fabrication methods for the formation of nanocluster arrangements on surfaces have been found, and they feature processes having various timescales, complexities, and versatilities. The fabrication of such structures can be discussed in terms of two processing steps that are independent of the actual process sequence. First, nanocomponents must be formed, which can be accomplished in various ways from precursors in the liquid, solid, or gas phases employing either chemical or physical deposition processes. In the second step, the challenge is to organize the segregated and deposited nanoparticles into structures or patterns on surfaces. Several approaches that use either a serial-writing-type process [2] or templates that allow fast parallel processing [3,4] have been formulated. More simple are the template-free approaches based on self-organization, which is the autonomous organization of components into patterns without human intervention.[5]Among all of these approaches, wet-chemical strategies utilizing fluid mechanics appear to be the simplest and most effective. Evaporation of drops on nonfunctionalized substrates has been used for the patterned deposition of solutes in DNA microarrays.[6] Furthermore, the ring deposition of particles from colloidal dispersions deposited as droplets has also been shown. [7] In addition to droplet drying, combined flow drying has been utilized for the deposition of semiconductor nanowires and nanotubes onto functionalized substrates.[8] The self-organization of matter into regular sub-micrometer-and nanoscale lines by using the wetting instability of a Langmuir-Blodgett film [9,10] as a cost-effective method has also been discussed. However, structuring of nanocluster arrays or wirelike morphologies from a droplet still faces certain challenges. Yawahare et al. [11] have demonstrated the room-temperature formation of lines from a drop if three prerequisites are met: evaporation between partially wetted surfaces, the presence of a pinning point, and the availability of a surfactant. In contrast to the above approaches, this paper presents a droplet-deposition-based, template-free, and rapid (only a few seconds) approach for fabricating nanostructures without the use of any surfactant. Our general setup can be understood as the so-called "anti-Lotus effect". The Lotus effect [12] is well known for its removal of dust particles from the surface of a lotus leaf by gathering them into a droplet that is moving over the surface, thus cleaning it. The effect is based on the ability of certain surfaces to form spherical droplets with contact angles near 180°(i.e., superhydrophobic), enabling the incorporation of surface particles as well as a reduction in friction. In contrast to this, our work makes use of an anti-Lotus effect,...

The scanning electron microscopy image (tilted, colored) shown on the inside cover depicts a ring of zinc oxide particles. This ring was obtained from a droplet of a highly diluted solution of zinc acetate by overheating on a 250°C hot silicon substrate, a method reported by Rainer Adelung and co‐workers on p. 1262. The overheating creates an explosion, which results in a spray of microscale droplets that form many rings similar to the one shown over a macroscopic substrate surface.