Weather-responsive adaptive shading through biobased and bioinspired hygromorphic 4D-printing

Abstract

Abstract In response to the global challenge of reducing carbon emissions and energy consumption from regulating indoor climates, we investigate the applicability of biobased cellulosic materials and bioinspired 4D-printing for weather-responsive adaptive shading in building facades. Cellulose is an abundantly available natural material resource that exhibits hygromorphic actuation potential when used in 4D-printing to emulate motile plant structures in bioinspired bilayers. Three key aspects are addressed: (i) examining the motion response of 4D-printed hygromorphic bilayers to both temperature and relative humidity, (ii) verifying the responsiveness of self-shaping shading elements in lab-generated conditions as well as under daily and seasonal weather conditions for over a year, and (iii) deploying the adaptive shading system for testing in a real building facade by upscaling the 4D-printing manufacturing process. This study demonstrates that hygromorphic bilayers can be utilized for weather-responsive facades and that the presented system is architecturally scalable in quantity. Bioinspired 4D-printing and biobased cellulosic materials offer a resource-efficient and energy-autonomous solution for adaptive shading, with potential contributions towards indoor climate regulation and climate change mitigation.