Extremely Stable, Multidirectional, All-in-One Piezoelectric Bending Sensor with Cycle up to Million Level

Flexible bending sensors are crucial components of flexible/wearable electronics. However, their broad application is restricted by their difficulty in sensing different bending directions and, more importantly, their significant output attenuation after long cycles. Herein, a new design of an All-in-One piezoelectric bending sensor is proposed, in which double-deck, cross-over 3D interdigital microelectrodes (silver nanowires (Ag NWs)) are embedded in a piezoelectric polymer film (poly(vinylidene fluoride-trifluoroethylene (P(VDF-TrFE))). The piezoelectric film with the embedded 3D microelectrodes exhibits a high anisotropy coefficient ((Formula presented.) > 1) based on dual piezoelectric modes (d₃₁ and d₃₃), which renders it more sensitive to different bending directions. More importantly, the homogeneous interconnected interface and heterogeneous microinterlocked interface formed inside the sensor significantly enhance its interface mechanical properties, with at least a tensile strength of 51 MPa, a shear strength of 28 MPa, and an interfacial toughness of 300 J m⁻², which are nearly two orders of magnitude greater than those of conventional sandwich architectures. The prepared All-in-One sensor shows an extremely stable piezoelectric output over as many as 16 00 000 bending cycles, which represents a remarkable breakthrough. Furthermore, a single sensor can be used to remotely control the multidirectional motion of a smart car, demonstrating enormous potential in practical applications.