Template-assisted GLAD: approach to single and multipatch patchy particles with controlled patch shape.

Template-assisted glancing angle deposition (GLAD) is explored for the fabrication of single and multipatch patchy particles with one or more patches of controlled but asymmetric shape. The template is used to ensure the formation of uniform patchy particles, whereas rotation of the template gives access to a large number of asymmetric patch shapes caused by the shadowing effect of the templating groove and/or the neighboring particle. Careful analysis with a straightforward geometric model reveals the effect of the angle of incidence, rotational angle, groove size, and particle size on the patch shape. Initial magnetic field assembly results are presented to illustrate the removal of patchy particles from their template and accessibility to a large number of patchy particles. Two-patch particles with overlapping patches are also accessible by means of secondary metal vapor deposition. The connectivity of these two patches on each particle and the predictable size of the overlapping section provide access to functional patchy particles. The combination of the template-assisted GLAD method with rotation of the template and secondary evaporation is demonstrated to be a good method for fabricating patchy particles with a variety of asymmetric patch shapes, sizes, and multipatches where every particle of a batch carries exactly the same patch pattern and thereby provides valuable input on experimentally accessible patch shapes for future experimental and computational studies of patchy particles.