Monolithic piezoceramic actuators with a twist

Designing artificial structures with heterogeneous elements and manipulating their interface coupling ways usually bring in synthetic neo-nature to functional devices. For piezoceramic devices, the deformation response refers to a variety of extensional, contractional, or shear modes of crystals, and also relies on boundary conditions from morphology design. However, to pursue fundamental torsion actuation in an integrated piezoceramic component is still a long-term tough task due to nil twist mode limited by microscopic crystal mirror symmetry. Herein, we demonstrate a design of cofired monolithic actuators to originally overcome this obstacle. The prototype device is composed of two sets of stacked actuation subunits that work on artificially reverse face shear modes, and their chiral stiffness couplings will synergistically contribute to synthetic twist outputs at a broad bandwidth. Finite element simulation reveals twist displacements are highly tunable by manipulating the geometrical dimensions. Transverse deflection measurements manifest the stable and sizeable linear actuation response to applied electric fields (around 3.7 µm under 40 V at 1 Hz). Importantly, the design actually introduces a more general route to enable arbitrary modes and actuation states in integrated piezoceramic components.