Curvature Induced by Deflection in Thick Meta-Plates.
The design of advanced functional devices often requires the use of intrinsically curved geometries that belong to the realm of non-Euclidean geometry and remain a challenge for traditional engineering approaches. Here, it is shown how the simple deflection of thick meta-plates based on hexagonal cellular mesostructures can be used to achieve a wide range of intrinsic (i.e., Gaussian) curvatures, including dome-like and saddle-like shapes. Depending on the unit cell structure, non-auxetic (i.e., positive Poisson ratio) or auxetic (i.e., negative Poisson ratio) plates can be obtained, leading to a negative or positive value of the Gaussian curvature upon bending, respectively. It is found that bending such meta-plates along their longitudinal direction induces a curvature along their transverse direction. Experimentally and numerically, it is shown how the amplitude of this induced curvature is related to the longitudinal bending and the geometry of the meta-plate. The approach proposed here constitutes a general route for the rational design of advanced functional devices with intrinsically curved geometries. To demonstrate the merits of this approach, a scaling relationship is presented, and its validity is demonstrated by applying it to 3D-printed microscale meta-plates. Several applications for adaptive optical devices with adjustable focal length and soft wearable robotics are presented.
['Mirzaali|Mohammad J|MJ|https://orcid.org/0000-0002-5349-6922', 'Ghorbani|Aref|A|https://orcid.org/0000-0002-6706-6966', 'Nakatani|Kenichi|K|', 'Nouri-Goushki|Mahdiyeh|M|https://orcid.org/0000-0003-1665-9144', 'Tümer|Nazli|N|', 'Callens|Sebastien J P|SJP|', 'Janbaz|Shahram|S|', 'Accardo|Angelo|A|', 'Bico|José|J|https://orcid.org/0000-0002-3872-1239', 'Habibi|Mehdi|M|https://orcid.org/0000-0003-4672-0516', 'Zadpoor|Amir A|AA|https://orcid.org/0000-0003-3234-2112']
auxeticity Gaussian curvature 3D printing functional materials mechanical metamaterials