Method for modifying an initial stress state of an active layer to a final stress state

摘要

This process comprises steps of: a) providing a first substrate comprising the active layer made of a first material of Young's modulus E1 and of thickness h1; b) providing a second substrate made of a second material of Young's modulus E2 and of thickness h2; c) bending the first substrate and the second substrate such that they each have a curved shape of a radius of curvature R; d) joining the second substrate to the active layer such that the second substrate closely follows the shape of the first substrate; and e) re-establishing the initial at-rest shape of the second substrate, the process being noteworthy in that the second material of the second substrate is a flexible material respecting the relationship E2/E1<10−2, in that the thickness of the second substrate respects the relationship h2/h1≧104, and in that the radius of curvature respects the relationship;R=h22⁢⁢ɛ.

主权项

1. A method for modifying an initial strain state of an active layer to a final strain state denoted ε, the process comprising steps of:
a) providing a first substrate comprising the active layer in the initial strain state, the active layer comprising a first material having a Young's modulus denoted E1, the active layer having a thickness denoted h1; b) providing a second substrate comprising a flexible second material having a Young's modulus denoted E2, the second substrate having a thickness denoted h2, the second substrate having an initial shape at rest, and selecting the second substrate and the flexible second material such that E2/E1<10−2 and such that h2/h1≧104; c) bending the first substrate and the second substrate such that they each have a curved shape of substantially identical radius of curvature denoted R, and selecting the radius of curvature such thatR=h22⁢ɛ; d) joining the second substrate to the active layer such that the second substrate closely follows the shape of the first substrate; and e) re-establishing the initial at-rest shape of the second substrate such that the active layer has the final strain state.