Foldable apparatus and methods of making
Foldable apparatus can comprise a first portion comprising a first edge surface defined between a first surface area and a second surface area opposite the first surface area. Foldable apparatus can comprise a second portion comprising a second edge surface defined between a third surface area and a fourth surface area opposite the third surface area. A polymer-based portion can be positioned between the first blunted edge surface and the second blunted edge surface. In some embodiments, the polymer-based portion can comprise a polymer thickness of about 50 micrometers or less measured from the second surface area and/or the first surface area. In some embodiments, the first edge surface and/or the second edge surface can comprise a blunted edge surface. In some embodiments, a coating can be disposed over the first portion, the second portion and the polymer-based portion.
1 . A foldable apparatus comprising:
a first portion comprising a first surface area and a second surface area opposite the first surface area, a first edge surface defined between the first surface area and the second surface area, a first blunted edge surface of the first edge surface comprises an outwardly convex edge surface, the outwardly convex edge surface is a rounded edge surface that comprises an entire first edge surface, and a first thickness defined between the first surface area and the second surface area;
a second portion comprising a third surface area and a fourth surface area opposite the third surface area, a second edge surface defined between the third surface area and the fourth surface area, and a second thickness defined between the third surface area and the fourth surface area; and
a polymer-based portion positioned between the first edge surface and the second edge surface and further extending beyond a plane defined by the second surface area and the fourth surface area to contact the second surface area of the first portion and the fourth surface area of the second portion, the polymer-based portion comprises a third contact surface and a fourth contact surface opposite the third contact surface, and the polymer-based portion comprises a polymer thickness of about 50 micrometers or less measured from the second surface area of the first portion in a direction of the first thickness.
2 . The foldable apparatus of claim 1 , further comprising a first adhesive layer comprising a first contact surface and a second contact surface opposite the first contact surface, wherein the second contact surface faces the first surface area and the third surface area.
3 . The foldable apparatus of claim 2 , wherein a thickness of the first adhesive layer defined between the first contact surface and the second contact surface is in a range from about 1 micrometer to about 30 micrometers.
4 . The foldable apparatus of claim 2 , wherein the third contact surface of the polymer-based portion contacts the second contact surface of the first adhesive layer.
5 . The foldable apparatus of claim 2 , wherein the first surface area of the first portion contacts the second contact surface of the first adhesive layer, and the third surface area of the second portion contacts the second contact surface of the first adhesive layer.
6 . The foldable apparatus of claim 2 , wherein the first adhesive layer comprises an elastic modulus is in a range from about 0.001 MegaPascals to about 0.5 MegaPascals.
7 . The foldable apparatus of claim 2 , wherein the first adhesive layer comprises an elastic modulus is in a range from about 250 MegaPascals to about 4 GigaPascals.
8 . The foldable apparatus of claim 1 , further comprising a first substrate comprising a first substrate thickness defined between a first major surface and a second major surface opposite the second major surface, and the second major surface of the first substrate facing the first surface area of the first portion and the third surface area of the second portion.
9 . The foldable apparatus of claim 1 , further comprising a coating disposed over the first portion, the second portion, and the polymer-based portion, wherein the coating comprises a coating thickness in a range from about 0.1 micrometers to about 200 micrometers.
10 . The foldable apparatus of claim 9 , wherein the coating comprises one or more of an ethylene-acid copolymer, a polyurethane-based polymer, an acrylate resin, or a mercapto-ester resin.
11 . The foldable apparatus of claim 1 , wherein the foldable apparatus achieves an effective bend radius of about 20 millimeters.
12 . The foldable apparatus of claim 1 , wherein a minimum distance between the first edge surface of the first portion and the second edge surface of the second portion is in a range from about twice an effective minimum bend radius to about 60 millimeters.
13 . The foldable apparatus of claim 1 , wherein a minimum distance between the first edge surface of the first portion and the second edge surface of the second portion is in a range from about 1 millimeter to about 100 millimeters.
14 . The foldable apparatus of claim 1 , wherein the polymer-based portion comprise an elastomer.
15 . The foldable apparatus of claim 1 , wherein the second blunted edge surface of the second edge surface comprises an outwardly convex edge surface.
16 . The foldable apparatus of claim 1 , wherein the foldable apparatus resists failure for a pen drop height of 15 centimeters over a location of the first portion.
17 . The foldable apparatus of claim 1 , wherein a force to bend the foldable apparatus from a flat configuration to a parallel plate distance of about 10 millimeters is about 10 Newtons or less.