Figure 3.

Schematic overview of template-directed assembly on an ordered microsphere array, (a), as developed by Grego et al. (2005), (b) (image reproduced with kind permission of S. Grego the American Chemical Society). Photolithography (a(i)) is used to produce a patterned resist. RIE, (a(ii)), etches the base substrate exposed by the resist, producing wells of carefully selected dimensions in the substrate following resist removal, (a(iii)). Microspheres with dimensions corresponding to those of the wells, fill individual wells, (a(iv)), providing a template to assist in the ordering of a second set of microspheres, (a(v)). The final device and underlying sequential structures can be seen in the SEM image in (b). Scale bar=5 μm.