A Review of Innovative Materials for the Design of Adaptive Biomimetic Façades

For several years now, the debate on climate change has become increasingly central because of the consequences of climate anomalies for different sectors of human activity and the built environment. According to the latest Working Group 1 Intergovernmental Report on Climate Change (IPCC), the level of global warming can exceed 1.5 °C in the coming decades. With the increase in the average temperature in the Mediterranean area, there will probably be an aggravation in the incidence of heatwaves and intense rainfall with significant repercussions in environmental, social, and economic terms. Therefore, solutions are needed to cope with these problems, and research lines are increasingly focused on the development of adaptive building envelopes to curb the adverse consequences of climate change. The study refers to ongoing experimental research that aims to define an adaptive component, for continuous facade systems, using innovative materials based on the biomimetic approach. In this paper, the authors present some parts of their research results, where a necessary step was a systematic review of adaptive façade systems, whose variability is related to the intrinsic properties of the material they are made of. Assuming nature as a model, the authors study molecular-scale or nanomaterial materials that change their configuration and adapt to an external stimulus, organically and passively, without the requirement of sophisticated energy systems. For example, materials regulate their adaptive behavior through modifications that alter their interior structure, such as a temperature difference, or by exchanging energy from one form to another. Incorporating these biomimetic principles in the definition of the component can contribute to the design of sustainable architectural systems to “tune” the façade to changing external climatic conditions.