摘要 |
<p>Apparatus including: a substrate, having a substrate surface, at least a portion of which is transparent or apertured; and an array of objects each having a maximum dimension smaller than 1 mm attached to the substrate and having an axis about which the object can rotate, wherein the object has two stable positions, a first stable position at which the object covers a transparent or apertured portion of the substrate and a second stable position at which the transparent portion is at least partially uncovered.</p> |