A method of manufacturing a foam showing a gradient poisson's ratio behaviour

摘要

There is disclosed a method of manufacturing a foam (1) having a Poisson's ratio which varies across at least a region (21) of the foam (1) in a gradient distribution. The method involves the steps of: a) providing a housing (3) defining an internal space (4a) having an inlet aperture (11) and an outlet aperture (14), the inlet and outlet apertures (11, 14) being in fluid communication with the internal space (4a) and spaced from one another across the internal space (4a); b) providing an open-cell foam (1) of a size and shape configured to fit inside the internal space (4a) of the housing (3); c) positioning the foam (1) inside the internal space (4a) of the housing; d) establishing a flow of air through the foam (1) via the inlet and outlet apertures (11, 14); e) heating the foam (1) to a predetermined temperature whilst maintaining said flow of air through the foam; and f) subsequently cooling the foam (1) whilst continuing to maintain said flow of air through the foam. A foam of such a type is also disclosed.