Patent DE-102010008886-A1 (DE)
Title: Triple-shape memory polymer system useful in automotive applications e.g. self-repairing autobodies, comprises a first polymeric material layer, and a second polymeric material layer coupled to first polymeric material layer
Inventor: XIE TAO
IPC: B32B7/027
Filed: 2010-02-23
Abstract: The polymer system comprises a first polymeric material layer (42), a second polymeric material layer (44) coupled to the first polymeric material layer to form a bi-layer polymeric material (40), and an additional polymeric material layer coupled to the bi-layer polymeric material to form a multi-layer polymeric material. The first and second polymeric material layers respond to a first external stimulus and a second external stimulus respectively to transform the bi-layer polymeric material between an original shape and first temporary shapes (40B) and/or second temporary shape. The polymer system comprises a first polymeric material layer (42), a second polymeric material layer (44) coupled to the first polymeric material layer to form a bi-layer polymeric material (40), and an additional polymeric material layer coupled to the bi-layer polymeric material to form a multi-layer polymeric material. The first and second polymeric material layers respond to a first external stimulus and a second external stimulus respectively to transform the bi-layer polymeric material between an original shape and first temporary shapes (40B) and/or second temporary shape without delamination between the first and second polymeric material layers. The first external stimulus is different than the second external stimulus. The bi-layer polymeric material is deformed under a first stress from the original permanent shape to a first one of the two temporary shapes. The first external stimulus is applied to the bi-layer polymeric material and in the absence of stress to recover the bi-layer polymeric material from the second one of the two temporary shapes to the first one of the two temporary shapes. The first and second external stimulus is removed from the bi-layer polymeric material while maintaining the bi-layer polymeric material under the first and second stresses respectively. The second external stimulus is applied to the bi-layer polymeric material while deforming the bi-layer polymeric material under a second stress to transform the bi-layer polymeric material from the first two temporary shapes to a second two temporary shapes and in the absence of stress to recover the bi-layer polymeric material from the first two temporary shape to the original shapes. A layer of the additional material layer responds to a third external stimulus to transform the multi-layer polymeric material between the original shape and two distinct temporary shapes without delamination between any coupled layers of the multi-layer polymeric material. The third external stimulus is different than both the first external stimulus and the second external stimulus. The first, second and third external stimulus comprise temperature, magnetism, light and/or moisture. An independent claim is included for a method of forming a polymer system having a triple shape memory effect.