Damage-tolerant 3D-printed ceramics via conformal coating.

Ceramic materials, despite their high strength and modulus, are limited in many structural applications due to inherent brittleness and low toughness. Nevertheless, ceramic-based structures, in nature, overcome this limitation using bottom-up complex hierarchical assembly of hard ceramic and soft polymer, where ceramics are packaged with tiny fraction of polymers in an internalized fashion. Here, we propose a far simpler approach of entirely externalizing the soft phase via conformal polymer coating over architected ceramic structures, leading to damage tolerance.

Deformation resilient cement structures using 3D-printed molds.

Cementitious structures exhibit high compression strength but suffer from inherent brittleness. Conversely, nature creates structures using mostly brittle phases that overcome the strength-toughness trade-off, mainly through internalized packaging of brittle phases with soft organic binders. Here, we develop complex architectures of cementitious materials using an inverse replica approach where a soft polymer phase emerges as an external conformal coating.

Nonlinear bending deformation of soft electrets and prospects for engineering flexoelectricity and transverse (d) piezoelectricity.

Soft materials that exhibit electromechanical coupling are an important element in the development of soft robotics, flexible and stretchable electronics, energy harvesters, sensor and actuators. Truly soft natural piezoelectrics essentially do not exist and typical dielectric elastomers, predicated on electrostriction and the Maxwell stress effect, exhibit only a one-way electromechanical coupling. Extensive research however has shown that soft electrets i.