The layered structures widely existing in natural world such as shells or trees

often bring excellent performances or special features. As the application of biomimetic science in polymer processing field

micro/nanolayer coextrusion technology offers a new method to fabricate alternating multilayer polymers with good physical properties. By virtue of the special design of the flow channels

the polymeric melt would experience an iterative layer-multiplying process and be imposed by multiple stresses

which provides an opportunity to tailor the morphology and microstructure of polymer materials. Additionally

the confined layer spaces generated by the alternating multilayer structure not only endows excellent mechanical

optical

electrical and barrier properties

but also supplies an ideal model for researching polymer crystallization. This paper presents a review of the recent progress of structural development and related properties of polymer materials in confined layer spaces.