| abstract |
Foldable apparatus can comprise a foldable substrate comprising a thickness (T) and a plurality of grooves extending through a first major surface. A groove spacing (Gs) is defined between a pair of grooves. A first groove of the plurality of grooves comprises a groove depth (Gd) and a groove width (Gw). In some embodiments, 7.93 - 6.19*(Gw/T) - 9.52*(Gd/T) + 6.05*(Gs/T) < 0. In some embodiments, (Gw/T) ≥ 0.1, (Gs/T) ≤ 1.5, 0.3 ≤ Gd/T ≤ 0.95. In some embodiments, a combined groove volume divided by a central volume can be about 0.3 or more. Methods of making a foldable apparatus comprise drawing a ribbon from a quantity of molten material off a forming device. Methods further comprising impinging a target location of the ribbon traveling in a draw direction with a laser beam to form a groove in the ribbon. In some embodiments, the groove can comprise a plurality of grooves. |