Breaking Barriers: Molding Thermodynamics by Geometry of Nanostructures

Convective, conductive, and radiative mechanisms of thermal and optical management are essential for life, and they are often interwoven with geometry in Nature. Nanostructured materials have properties that depend on size and shape, are entirely different from their bulk counterpart, and very often exhibit size-dependent physical responses. In this study, we reveal the effect of corrugation and geometry on thermodynamic properties, i.e., heat capacity. The presented results highlight that the multifaceted geometry of natural photonic structures strongly shapes the thermodynamic response of the composite system, and, in some extreme cases, exhibits negative heat capacity. Besides the fundamental importance of revealing the geometrical constraints responsible for unusual thermodynamic response, the presented study offers the concept of shaping heat capacity on command by controlling the geometry of the system without changing its chemistry.